[HN Gopher] Willow, Our Quantum Chip
       ___________________________________________________________________
        
       Willow, Our Quantum Chip
        
       Author : robflaherty
       Score  : 1324 points
       Date   : 2024-12-09 16:28 UTC (1 days ago)
        
 (HTM) web link (blog.google)
 (TXT) w3m dump (blog.google)
        
       | tombert wrote:
       | Interesting; it might be time for me to load up a quantum
       | simulator and star learning how to program these things.
       | 
       | I've pushed that off for a long time since I wasn't completely
       | convinced that quantum computers actually worked, but I think I
       | was wrong.
        
         | nick__m wrote:
         | IBM has well structured learning material and a quantum
         | simulator at https://learning.quantum.ibm.com/
         | 
         | Also my almamater made the quantum enigmas series that is
         | appropriate for high-school students (it also interesting if
         | you have no prior knowledge about quantum computing)
         | https://www.usherbrooke.ca/iq/quantumenigmas/ (it also use IBM
         | online learning platform)
        
       | gordon_freeman wrote:
       | So one of the interesting comparisons between Quantum computing
       | vs classical in the video: 5 mins vs 10^25 years. So are there
       | any tradeoffs or specific cases in which the use cases for
       | Quantum computing works or is this generic for "all" computing
       | use cases? if later then this will change everything and would
       | change the world.
        
         | dabeeeenster wrote:
         | Its for a very, very, very narrow set of algorithms AFAIUI.
        
         | antognini wrote:
         | There are only certain kinds of computing tasks which are
         | amenable to an exponential speedup from quantum computing. For
         | many classical algorithms the best you get from a quantum
         | computer is an improvement by a factor of sqrt(N) by using
         | Grover's algorithm.
         | 
         | The other tradeoff is that quantum computers are much noisier
         | than classical computers. The error rate of classical computers
         | is exceedingly low, to the extent that most programmers can go
         | their entire career without even considering it as a
         | possibility. But you can see from the figures in this post that
         | even in a state of the art chip, the error rates are of order
         | ~0.03--0.3%. Hopefully this will go down over time, but it's
         | going to be a non-negligible aspect of quantum computing for
         | the foreseeable future.
        
         | pitpatagain wrote:
         | It is specific to cases where a quantum algorithm exists that
         | provides speedup, it is not at all generic. The complexity
         | class of interest is BQP: https://en.wikipedia.org/wiki/BQP
         | 
         | Also of note: P is in BQP, but it is not proven that BQP != P.
         | Some problems like factoring have a known polynomial time
         | algorithm, and the best known classical algorithm is
         | exponential, which is where you see these massive speedups. But
         | we don't know that there isn't an unknown polynomial time
         | classical factoring algorithm and we just haven't discovered it
         | yet. It is a (widely believed) conjecture, that there are hard
         | problems solved in BQP that are outside P.
        
       | nuz wrote:
       | Every time this comes up people say they're not actually useful
       | for ML. Is that true? And if not what would they be useful for
        
         | christkv wrote:
         | In principal NP complete problems is my guess.
        
           | wazdra wrote:
           | It is unknown whether quantum computing makes NP-complete
           | problems easier to solve. There is a complexity class for
           | problems that can be solved "efficiently" on using quantum
           | computing, called BQP. How BQP and NP are related is unknown.
           | In particular, if an NP-complete problem was shown to be
           | solvable efficiently with Quantum Computing (and thus in
           | BQP), this open (and hard) research question would be solved
           | (or at least half of it).
           | 
           | Note that BQP is not "efficient" in a real-word fashion, but
           | for theoretical study of Quantum computing, it's a good first
           | guess
        
           | benbayard wrote:
           | AFAIK, which is not much, I believe it is problems that you
           | can turn in to a cycle. Right now we pull out answers from
           | quantum computers at random, but typically do not know what
           | the inputs were that got that answer. But if you can get the
           | answers from the quantum computer to be cyclical you can use
           | that symmetry to get all the information you need.
        
         | whimsicalism wrote:
         | breaking crypto, for one
        
         | LampCharger wrote:
         | No, a true quantum computer will not necessarily solve NP-
         | complete (NPC) problems efficiently. Quantum algorithms like
         | Grover's provide quadratic speedups, but this is insufficient
         | to turn exponential-time solutions into polynomial-time ones.
         | While quantum computers excel in specific tasks (e.g., Shor's
         | algorithm for factoring), there's no evidence they can solve
         | all NP-complete problems efficiently.
         | 
         | Current complexity theory suggests that , the class of problems
         | solvable by quantum computers, does not encompass . Quantum
         | computers may aid in approximations or heuristics for NPC
         | problems but won't fundamentally resolve them in polynomial
         | time unless , which remains unlikely.
        
         | vessenes wrote:
         | Factoring. Reversing ECC operations. Decrypting all the data
         | thought to be safely stored at rest in any non quantum
         | resistant storage.
         | 
         | I do think ai algorithms could be built that quantum gates
         | could be fast at, but I don't have any ideas off the top of my
         | head this morning. If you think of AI training as searching the
         | space of computational complexity and quantum algorithms as
         | accessing a superposition of search states I would guess
         | there's an intersection. Google thinks so too - the lab is
         | called quantum ai.
        
       | jawns wrote:
       | > It lends credence to the notion that quantum computation occurs
       | in many parallel universes, in line with the idea that we live in
       | a multiverse
       | 
       | I see the evidence, and I see the conclusion, but there's a lot
       | of ellipses between the evidence and the conclusion.
       | 
       | Do quantum computing folks really think that we are borrowing
       | capacity from other universes for these calculations?
        
         | gaze wrote:
         | I'm upset they put this in because this is absolutely not the
         | view of most quantum foundations researchers.
        
           | whimsicalism wrote:
           | the everettian view is absolutely not the view? i am not so
           | sure.
           | 
           | or you mean specifically the parallel computation view?
        
             | gaze wrote:
             | sorry -- the results don't add weight to one view or the
             | other. The interpretations are equivalent.
        
               | whimsicalism wrote:
               | not metaphysically equivalent. also, i'm not so certain
               | it will always be untestable. i would have thought the
               | same thing about hidden variables but i underestimated
               | the cleverness of experimentalists
        
               | DennisP wrote:
               | I think "experimentally equivalent" is what GP meant, and
               | as of today, it holds true. Google's results are
               | predicted by other interpretations just as well as by
               | Everett. Maybe someday there will be a clever experiment
               | to distinguish the models but just "we have a good QC" is
               | not that.
        
               | whimsicalism wrote:
               | i think you're arguing against a point i never made in
               | any of my comments
        
             | wasabi991011 wrote:
             | In my opinion the "shut up and calculate" view is the most
             | common among actual quantum computing researchers.
             | 
             | Unsure about those working on quantum foundations, but I
             | think the absence of consensus is enough to claim any view
             | as absolutely not _the_ view.
        
               | whimsicalism wrote:
               | i don't really view "shut up and calculate" or very
               | restrained copenhagenism as a real view at all.
               | 
               | i think if you were to ask people to make a real
               | metaphysical speculation, majority might be partial to
               | everett - especially if they felt confident the results
               | were anonymous
        
               | wasabi991011 wrote:
               | I agree, but that kind of goes to my point:
               | 
               | I believe the vast majority of researchers in quantum
               | computing* spend almost no time on metaphysical
               | speculation,
               | 
               | *Well, those on the "practical side" that thinks about
               | algorithms and engineering quantum systems like the
               | Google Quantum AI team and others. Not the computer
               | science theorists knee-deep in quantum computational
               | complexity proofs nor physics theorists working on
               | foundations of quantum mechanics. But these last two
               | categories are outnumbered by the "practical" side.
        
               | spookie wrote:
               | Seeing to believe is indeed a view, as they would have to
               | view it in order to believe!
        
           | klipt wrote:
           | Soon: "are alien universes slowing down _your_ internet?
           | Click here to learn more! "
           | 
           | Reminds me of the Aorist Rods from Hitchhikers' Guide to the
           | Galaxy.
        
             | rafram wrote:
             | Well there has to be _some_ reason I 'm not getting the
             | "gigabit" speeds I was quoted.
        
               | duderific wrote:
               | You were probably quoted "up to" gigabit speed. Which
               | means anything from zero to gigabit is acceptable.
        
               | sebastiennight wrote:
               | Are negative speeds acceptable too?
        
           | ColinHayhurst wrote:
           | Credibility of the article plummeted when I got to that
           | sentence, and especially since using name dropping.
        
           | ferfumarma wrote:
           | One of the biggest problems with such an assertion is that
           | it's not falsifiable.
           | 
           | It could be that we are borrowing qbit processing power from
           | Russel's quantum teapot.
        
           | hshshshshsh wrote:
           | Science is not based on consensus seeking.
           | 
           | Science is about coming up with the best explanations
           | irrespective of whether or not a large chunk does not believe
           | it.
           | 
           | And best explanations are the ones that is hard to vary. Not
           | the one that is most widely accepted or easy to accept based
           | on the current world view.
        
             | jayd16 wrote:
             | Actually it is exactly based on hypotheses that are
             | verified.
        
               | hshshshshsh wrote:
               | And how do you verify hypothesis? What is the process to
               | do that?
        
               | fwip wrote:
               | You use the hypotheses to make predictions and design
               | experiments. Then you carry those out and see if they
               | support the hypothesis.
               | 
               | Or is this one of those rhetorical questions?
        
               | hshshshshsh wrote:
               | Okay. I have a hypothesis that the rain is controlled by
               | a god called Ringo. If you pray to Ringo and he listens
               | to your prayer it will rain in next 24 hours. If he
               | doesn't listen it won't rain. You can also test this
               | experimentally by praying and observing the outcomes.
        
               | kelnos wrote:
               | I assume this is a rhetorical question, since you are
               | perfectly capable of doing a search for "the scientific
               | method" on your own.
               | 
               | MWI has not led to any verifiably-correct predictions,
               | has it? At least not any that other interpretations can
               | also predict, and have other, better properties.
        
               | JanisErdmanis wrote:
               | I think the idea here is that the choice on which
               | hypothesis to verify is based on the risk assessment of
               | the scientist whose goal is to optimize successful
               | results and hence better theories are more likely to
               | surface. In this way one does not need to form a
               | consensus around the theory but instead make consensus on
               | what constitutes a successful result.
               | 
               | Ideally this would be true, but funding agencies are
               | already preloaded with implicit asssumptions what
               | constitutes a scientific progress.
        
             | brisky wrote:
             | David is this you?
        
             | kelnos wrote:
             | > _Science is not based on consensus seeking._
             | 
             | No, but as non-experts in a given field, the best
             | information we have to go on is the consensus among
             | scientists who _are_ experts in the field.
             | 
             | Certainly this isn't a perfect metric, and consensus-
             | smashing evidence sometimes comes to light, but unless and
             | until that happens, we should assume that the people who
             | study this sort of thing as their life's work are probably
             | more correct than we are.
        
           | justinpombrio wrote:
           | From Wikipedia[1]:
           | 
           | A poll of 72 "leading quantum cosmologists and other quantum
           | field theorists" conducted before 1991 by L. David Raub
           | showed 58% agreement with "Yes, I think MWI is true".[85]
           | 
           | Max Tegmark reports the result of a "highly unscientific"
           | poll taken at a 1997 quantum mechanics workshop. According to
           | Tegmark, "The many worlds interpretation (MWI) scored second,
           | comfortably ahead of the consistent histories and Bohm
           | interpretations."[86]
           | 
           | In response to Sean M. Carroll's statement "As crazy as it
           | sounds, most working physicists buy into the many-worlds
           | theory",[87] Michael Nielsen counters: "at a quantum
           | computing conference at Cambridge in 1998, a many-worlder
           | surveyed the audience of approximately 200 people... Many-
           | worlds did just fine, garnering support on a level comparable
           | to, but somewhat below, Copenhagen and decoherence." But
           | Nielsen notes that it seemed most attendees found it to be a
           | waste of time: Peres "got a huge and sustained round of
           | applause...when he got up at the end of the polling and asked
           | 'And who here believes the laws of physics are decided by a
           | democratic vote?'"[88]
           | 
           | A 2005 poll of fewer than 40 students and researchers taken
           | after a course on the Interpretation of Quantum Mechanics at
           | the Institute for Quantum Computing University of Waterloo
           | found "Many Worlds (and decoherence)" to be the least
           | favored.[89]
           | 
           | A 2011 poll of 33 participants at an Austrian conference on
           | quantum foundations found 6 endorsed MWI, 8 "Information-
           | based/information-theoretical", and 14 Copenhagen;[90] the
           | authors remark that MWI received a similar percentage of
           | votes as in Tegmark's 1997 poll.[90]
           | 
           | [1] https://en.wikipedia.org/wiki/Many-
           | worlds_interpretation#Pol...
        
             | whimsicalism wrote:
             | i think if these polls were anonymous, copenhagen would
             | lose share. there's a reason why MWI is disproportionately
             | popular among people who basically have no professional
             | worries because they are already uber-distinguished.
        
         | korkybuchek wrote:
         | > Do quantum computing folks really think that we are borrowing
         | capacity from other universes for these calculations?
         | 
         | Tangentially related, but there's a great Asimov book about
         | this called The Gods Themselves (fiction).
        
           | vessenes wrote:
           | I'm partial to Anathem by Stephenson on this topic as well
        
             | korkybuchek wrote:
             | Thanks for the recommendation!
        
         | wasabi991011 wrote:
         | I was also really taken aback by this quote.
         | 
         | I have no idea who put it there, but I can assure you the
         | actual paper contains no such nonsense.
         | 
         | I would have thought whoever writes the google tech blogs is
         | more competent than bottom tier science journalists. But in
         | this case I think it is more reasonable to assume malice, as
         | the post is authored by the Google Quantum AI Lead, and makes
         | more sense as hype-boosting buzzword bullshit than as an honest
         | misunderstanding that was not caught during editing.
        
           | hshshshshsh wrote:
           | Quantum computation done in done multiple universes is the
           | explanation given by David Deutsch the father of Quantum
           | Computing. He invented the idea of a quantum computer to test
           | the idea of parallel universes.
           | 
           | If you are okay with a single universe coming to existence
           | out of nothing you should be able to handle parallel
           | universes as well just fine.
           | 
           | Also your comment does not have any useful information. You
           | assumed hype as the reason why they mentioned parallel
           | computing. It's just a bias you have on looking at world.
           | Hype does helps explain a lot of things. So it can be
           | tempting to use it as a placeholder for anything that you
           | don't accept based on your current set of beliefs.
        
             | wasabi991011 wrote:
             | I disagree that it is "the best explanation we have". It's
             | a nice theory, but like all theories in quantum foundations
             | / interpretations of quantum mechanics, it is (at least
             | currently) unfalsifiable.
             | 
             | I didn't "assume" hype, I hypothesized it based on the
             | evidence before me: There is nothing in Google's paper that
             | deals with interpretations of quantum mechanics. This only
             | appears in the blog post, with no evidence given. And there
             | is nothing google is doing with it's quantum chip that
             | would discriminate between interpretations of QM, so it is
             | simply false that "It lends credence to ... parallel
             | universes" over another interpretation.
        
               | hshshshshsh wrote:
               | From what I understand, David Deutsch invented the idea
               | of quantum computer as a way to test Parallel Universes.
               | And later people went on and built the quantum computer.
               | Are you saying that the implementation of a quantum
               | computer does not require any kind of assumption on
               | computations being run in parallel universes?
        
               | Vecr wrote:
               | It's just not how it works. All this type of quantum
               | computer can do is test some of the more dubious
               | objective collapse theories. Those are wrong anyway, so
               | all theories that are still in the running agree.
        
               | lanternfish wrote:
               | In short, no.
        
               | kelnos wrote:
               | That's right, it doesn't. The implementation of a quantum
               | computer does not prove or disprove the existence of
               | parallel universes.
        
             | booleandilemma wrote:
             | _If you are okay with a single universe coming to existence
             | out of nothing you should be able to handle parallel
             | universes as well just fine._
             | 
             | We have evidence for this universe though.
        
               | oniony wrote:
               | I believe their point was that, if you accept the reality
               | of _this_ universe being created from nothing, why
               | wouldn't you also accept the notion of _other_ universes
               | similarly existing too.
               | 
               | I can get on board with that: that there may be other,
               | distinct universes, but I do not understand how this
               | would lead to the suggestion they would be necessarily
               | linked together with quantum effects.
        
               | nworno wrote:
               | Disagree with that. The fact that we reasonably accept a
               | well-proven theory (ie the observed universe exists) that
               | has some unexplained parts (we don't currently have a
               | reasonable explanation for where does that universe comes
               | from) doesn't mean that we should therefore accept any
               | unproven theory, especially a unfalsifiable one.
        
             | kelnos wrote:
             | > _If you are okay with a single universe coming to
             | existence out of nothing you should be able to handle
             | parallel universes as well just fine._
             | 
             | I can _handle_ it, sure, and the idea of the multiverse is
             | attractive to me from a philosophical standpoint.
             | 
             | But we have no evidence that there are any other universes
             | out there, while we do have plenty of evidence that our own
             | exists. Just because one of something exists, it doesn't
             | automatically follow that there are others.
        
           | movpasd wrote:
           | There are compelling arguments to believe in the many-worlds
           | interpretation.
           | 
           | No sign of a Heisenberg cut has been observed so far, even as
           | experiments involving entanglement of larger and larger
           | molecules are performed, which makes objective-collapse
           | theories hard to consider seriously.
           | 
           | Bohmian theories are nice, but require awkward adjustments to
           | reconcile them with relativity. But more importantly, they
           | are philosophically uneconomical, requiring many unobservable
           | -- even theoretically -- entities [0].
           | 
           | That leaves either many-worlds or a quantum logic/quantum
           | Bayesian interpretations as serious contenders [1]. These
           | interpretations aren't crank fringe nonsense. They are almost
           | inevitable outcomes of seriously considering the implications
           | of the theory.
           | 
           | I will say that personally, I find many-worlds to focus
           | excessively on the Schrodinger-picture pure state formulation
           | of quantum mechanics. (At least to the level that I
           | understood it -- I expect there is literature on the
           | connection with algebraic formulations, but I haven't taken
           | the time to understand it.) So I would lean towards quantum
           | logic-type interpretations myself.
           | 
           | The point of this comment was to say that many-worlds (or
           | "multiverses", though I dislike the term) isn't nonsense. But
           | it also isn't exactly the kind of sci-fi thing non-physicists
           | might picture. Given how easy it is to misinterpret the term,
           | however, I must agree with you that a self-aware science
           | communicator would think twice about whether the term should
           | be included, and that there may be not-so-scrupulous
           | intentions at play here.
           | 
           | Quick edit: I realise the comment I've written is very
           | technical. I'm happy to try to answer any questions. I should
           | preface it by stating that I'm not a professional in the
           | field, but I studied quantum information theory at a Masters
           | level, and always found the philosophical questions of
           | interest.
           | 
           | ---
           | 
           | [0] Many people seem to believe that many-worlds also
           | postulates the existence of unobservable parallel universes,
           | but this isn't true. We observe the interaction of these
           | universe's every time we observe quantum interference.
           | 
           | While we're here, we can clear up the misconception about
           | "branching" -- there is no branching in many-worlds, just the
           | coherent evolution of the universal wave function. The many
           | worlds are projections out of that wave function. They don't
           | discretely separate from one another, either -- it depends on
           | your choice of basis. That choice is where decoherence comes
           | in.
           | 
           | [1] And of course, there is the Copenhagen "interpretation"
           | -- preferred among physicists who would rather not think
           | about philosophy. (A respectable choice.)
        
             | Vecr wrote:
             | That's right, I agree that Multiple Worlds isn't any _less_
             | correct /falsifiable than quantum mechanics as a whole.
             | 
             | I've never heard about quantum logic before. The "Bayesian"
             | part makes sense because of how it treats the statistics,
             | but the logic? Is that what quantum computer scientists do
             | with their quantum circuits, or is it an actual
             | interpretation?
        
             | tsimionescu wrote:
             | I think the key point that makes the quoted statement
             | sciencey gibberish is that the Many Worlds Interpretation
             | is just that - an interpretation. There is no way to prove
             | or disprove it (except if you proved that the world is not
             | actually quantum mechanical, in which case MWI might not be
             | a valid interpretation of the new theory). Saying "this is
             | more evidence for MWI" is thus true of any quantum
             | mechanical experiment, but anything that is evidence for
             | MWI is also exactly as much evidence for Pilot Waves (well,
             | assuming it is possible to reconcile with quantum field
             | theory), the Copenhagen Interpretation, QBism, and so on.
             | 
             | As a side note, there is still a huge gap between the
             | largest system we've ever observed in a superposition and
             | the smallest system we've ever observed to behave only
             | classically. So there is still _a lot_ of room for
             | objective collapse theories, even though that space has
             | shrunk by some orders of magnitude since it was first
             | proposed. Of course, objective collapse has other, much
             | bigger, problems, such as being incompatible with Bell 's
             | inequalities.
             | 
             | Edit: I'd also note some things about MWI. First, there are
             | many versions of it, some historical, some current. Some
             | versions, at least older ones, absolutely did involve
             | explicit branching. And the ones that don't have a big
             | problem still with explaining why, out of the many ways to
             | choose the basis vectors for a measurement, we always end
             | up with the same classical measurables in every experiment
             | we perform on the world at large. Especially given that we
             | know we can measure quantum systems in another other basis
             | if we want to. It also ultimately doesn't answer the
             | question of why we need the Born rule at all, it still
             | postulates that an observer only has access to one possible
             | value of the wave function and not to all at once. And of
             | course, the problem of defining probabilities in a world
             | where everything happens with probability 1 is another
             | philosophically thorny issue, especially when you need the
             | probabilities to match the amplitude of the wave function.
             | 
             | So the MWI is nice, and it did spawn a very useful and
             | measurable observation, decoherence. But it's far from a
             | single, satisfying, complete, self-consistent account of
             | the world.
        
               | byteknight wrote:
               | I would argue because we can't postulate a means of
               | testing it now does not mean it is thereby impossible to
               | prove; merely currently.
        
               | tsimionescu wrote:
               | This would be true if we were talking about something
               | like String Theory, or Loop Quantum Gravity.
               | 
               | But it is not true for MWI: MWI was designed from the
               | ground up as an interpretation of the mathematics and
               | experimental results of quantum mechanics. It is designed
               | specifically to not match all of the predictions of
               | quantum mechanics, and to not make any new predictions.
               | Other interpretations are also designed in the same way.
               | 
               | So, if the people creating these interpretations
               | succeeded in their goals when making them, then they will
               | never be experimentally verifiable.
        
             | sesm wrote:
             | "Many-world interpretation" is just a religion, it has
             | nothing to do with physics. Pilot Wave is an example of a
             | physical theory, Copenhagen is an administrative agreement.
        
               | smolder wrote:
               | I'm pretty sure pilot wave is the same kind of
               | unfalsifiable interpretation of the experimental results
               | that MWI is. Also I think people are making too big a
               | deal out of the comment in the article. I took it as kind
               | of tongue-in-cheek. An expert would know MWI is
               | unfalsifiable and inconsequential.
        
               | sesm wrote:
               | No, Bell Inequality test falsified it.
        
               | smolder wrote:
               | Oh my mistake.
        
           | vixen99 wrote:
           | Presumably the 'nonsense' is the supposed link between the
           | chip and MW theory.
           | 
           | Let me add a recommendation for David Wallace's book The
           | Emergent Multiverse - a highly persuasive account of 'quantum
           | theory according to the Everett Interpretation'. Aside from
           | the technical chapters, much of it is comprehensible to non-
           | physicists. It seems that adherents to MW do 'not know how to
           | refute an incredulous stare'. (From a quotation)
        
         | ComputerGuru wrote:
         | It doesn't make sense to me because if we can borrow capacity
         | to perform calculations then we can "borrow" an infinite amount
         | of energy.
        
           | griomnib wrote:
           | Climate change solved: steal energy from adjacent universes,
           | pipe our carbon waste into theirs.
        
             | danielbln wrote:
             | Remind me of The Expanse, where the ring space is syphoning
             | energy from some other universe to keep the gates open.
        
             | kridsdale1 wrote:
             | It's "out of the environment".
        
               | griomnib wrote:
               | We're taking negative externalities to a whole new
               | dimension!
        
             | FridgeSeal wrote:
             | There's a fun short story in qntm's "Valuable Humans In
             | Transit" about a scenario like this.
        
         | rdtsc wrote:
         | > It lends credence to the notion that quantum computation
         | occurs in many parallel universes, in line with the idea that
         | we live in a multiverse, a prediction first made by David
         | Deutsch.
         | 
         | That's in line with a religious belief. One camp believes one
         | thing, other believes something else, others refuse to
         | participate and say "shut up and calculate". Nothing wrong with
         | religious beliefs of course, it's just important to know that
         | is what it is.
        
         | paxys wrote:
         | I don't understand the jump from: classical algorithm takes
         | time A -> quantum algorithm takes time B -> (A - B) must be
         | borrowed from a parallel universe.
         | 
         | Maybe A wasn't the most efficient algorithm for this universe
         | to begin with?
        
           | kelnos wrote:
           | Right, and that's part of the argument against quantum
           | computing being a proof (or disproof) of the many-worlds
           | interpretation. Sure, "(A-B) was borrowed from parallel
           | universes" is _a_ possible explanation for why quantum
           | computing can be so fast, but it 's by far not the only
           | possible explanation.
        
         | aithrowawaycomm wrote:
         | I suspect the real issue is that Big Tech investors and
         | executives (including Sundar Pichai) are utterly hopped up on
         | sci-fi, and this sort of stuff convinces them to dedicate
         | resources to quantum computing.
        
           | kridsdale1 wrote:
           | That explains metaverse funding at least.
        
         | ko27 wrote:
         | It's a perfectly legit interpretation of what's happening, and
         | many physicists share the same opinion. Of course the big
         | caveat is that you need to interfere those worlds so that they
         | cancel out, which necessarily requires a lower algorithmic
         | bound which prevents you from doing infinite amount of
         | computation in an instant.
        
         | johnfn wrote:
         | You don't even have to get to the point where you're reading a
         | post off Scott Aaronson's blog[1] at all; his headline says "If
         | you take nothing else from this blog: quantum computers won't
         | solve hard problems instantly by just trying all solutions in
         | parallel."
         | 
         | [1]: https://scottaaronson.blog/
        
         | aithrowawaycomm wrote:
         | In the same way people believe P != NP, most quantum computing
         | people believe BQP != NP, and NP-complete problems will still
         | take exponential time on quantum computers. But if we had
         | access to arbitrary parallel universes then presumably that
         | shouldn't be an issue.
         | 
         | The success on the random (quantum) circuit problem is really a
         | valdiation of Feynman's idea, not Deutsch: classical computers
         | need 2^n bits to simulate n qubits, so we will need quantum
         | computers to efficiently simulate quantum phenomena.
        
           | jumping_frog wrote:
           | Does access to arbitrary parallel universes imply that they
           | divide up the computation and the correct answer is
           | distributed to all of the universes or in such a collection,
           | there will be sucker universes which will always receive
           | wrong answers ?
        
             | aithrowawaycomm wrote:
             | Good question! The whole magic of quantum computation
             | versus parallel computation is that the "universe"
             | probabilities interfere with each other so that wrong
             | answers cancel each other out. So I suppose the wrong
             | "universes" still exist somewhere. But it's a whole lot
             | less confusing if you view QC as taking place in one
             | universe which is fundamentally probabilistic.
        
         | melvinmelih wrote:
         | > It performed a computation in under five minutes that would
         | take one of today's fastest supercomputers 1025 or 10
         | septillion years. If you want to write it out, it's
         | 10,000,000,000,000,000,000,000,000 years.
         | 
         | If it's not, what would be your explanation for this
         | significant improvement then?
        
           | Ar-Curunir wrote:
           | I mean, that's like saying GPUs operate in parallel universes
           | because they can do certain things thousands of times faster
           | than CPUs.
        
           | shawabawa3 wrote:
           | Quantum computing can perform certain calculations much
           | faster than classical computing in the same way classical
           | computing can perform certain calculations much faster than
           | an abacus
        
         | GenerWork wrote:
         | >Do quantum computing folks really think that we are borrowing
         | capacity from other universes for these calculations?
         | 
         | Doesn't this also mean that other universes have civilizations
         | that could potentially borrow capacity from our universe, and
         | if so, what would that look like?
        
         | hshshshshsh wrote:
         | The quantum computer idea was literally invented by David
         | Deutsche to test the many universes theory of quantum physics.
        
           | wasabi991011 wrote:
           | You've mentioned this in another comment. I have to point
           | out, even if this is his opinion, and he has been influential
           | in the field, it does not mean that this specific idea of his
           | has been influential.
        
             | hshshshshsh wrote:
             | Sorry. I don't care whether an idea was influential or not.
             | All I care is whether someone has a better explanation.
        
               | wasabi991011 wrote:
               | I'll remind you of the quote that started this thread:
               | 
               | "Do quantum computing folks really think that we are
               | borrowing capacity from other universes for these
               | calculations?"
               | 
               | In this context, your opinion and Deutsch's opinion don't
               | matter. The question is about whether the idea is common
               | in the field or not.
        
               | hshshshshsh wrote:
               | Okay. I just don't understand. Are you saying Quantum
               | Computers are also implemented without assuming the
               | computations run in parallel universe?
        
               | Vecr wrote:
               | I don't know what he's saying, but I'm saying that the
               | answer to your question is "Yes," unless quantum
               | computers behave differently than expected.
        
               | wasabi991011 wrote:
               | Correct. The laws of quantum mechanics (used for building
               | quantum computers among other things) make very little
               | assumptions on the nature of the universe, and support
               | multiple interpretations, many-worlds being only one of
               | them.
               | 
               | Quantum mechanics is a tool to calculate observable
               | values, and this tool works very successfully without
               | needing to make strong assumptions about the nature of
               | the universe.
        
           | Vegenoid wrote:
           | It is not useful to spam this comment repeatedly under
           | different people who question or disagree with many worlds.
           | Pick one place to make your case.
        
         | killerstorm wrote:
         | Everett interpretation simply asserts that quantum
         | wavefunctions are real and there's no such thing as
         | "wavefunction collapse". It's the simplest interpretation.
         | 
         | People call it "many worlds" because we can interact only with
         | a tiny fraction of the wavefunction at a time, i.e. other
         | "branches" which are practically out of reach might be
         | considered "parallel universes".
         | 
         | But it would be more correct to say that it's just one universe
         | which is much more complex than what it looks like to our eyes.
         | Quantum computers are able to tap into this complexity. They
         | make a more complete use of the universe we are in.
        
         | layer8 wrote:
         | The Schrodinger equation inherently contains a multiverse. The
         | disagreement is about whether the wave function described by
         | the equation collapses to a single universe upon measurement
         | (i.e. whether the equation stops holding upon measurement), or
         | whether the different branches continue to exist (i.e. the
         | equation continues to hold at all times), each with a different
         | measurement outcome. Regardless, between measurements the
         | different branches exist in parallel. It's what allows quantum
         | computation to be a thing.
        
           | Lionga wrote:
           | Non of that honkey ponkey is needed if you just give up
           | locality and a hard deterministic explanation like De-
           | Broglie-Bohm gives all the same correct measurements and
           | conclusions like Copenhagen interpretation without
           | multiverses and "wave function collapses".
           | 
           | Copenhagen interpretation is just "easier" (like oops all our
           | calculations about the univers don't seemt to fit, lets
           | invent "dark matter") when the correct explanations makes any
           | real world calculation practically impossible (thus ending
           | most of physics further study) as any atom depends on every
           | other atom at any time.
        
             | layer8 wrote:
             | De Broglie-Bohm doesn't remove anything from the wave
             | function, and thus all the pointer states therein contained
             | are still present. The theory basically claims that one of
             | them is special and _really_ exists, whereas the others
             | only mathematically exist, but philosophically it's not
             | clear what the difference would be. The Broglie-Bohm
             | ontology is bigger than MW rather than smaller.
        
           | wasabi991011 wrote:
           | > The Schrodinger equation inherently contains a multiverse.
           | 
           | A simple counterexample is superdeterminism, in which the
           | different measurement outcomes are an illusion and instead
           | there is always a single pre-determined measurement outcome.
           | Note that this does not violate Bell's inequality for hidden
           | variable theories of quantum mechanics, as Bell's inequality
           | only applies to hidden variables uncorrelated to the choice
           | of measurement: in superdeterminism, both are predetermined
           | so perfectly correlated.
        
           | creata wrote:
           | > The Schrodinger equation inherently contains a multiverse.
           | 
           | Just to be clear, where in the Schrodinger equation (ihps =
           | Hps) is the "multiverse"?
        
             | layer8 wrote:
             | When taking the entire universe as a quantum system
             | governed by the Schrodinger equation, then ps is the
             | universal wavefunction, and its state vector can be
             | decomposed into pointer states that represent the
             | "branches" of MW.
        
         | varjag wrote:
         | Yes this is deeply unserious tangent in supposedly landmark
         | technology announcement.
        
           | athesyn wrote:
           | It's just marketing.
        
             | varjag wrote:
             | Oh, are they selling these?
        
             | mrguyorama wrote:
             | "Just marketing" in science journalism and publications is
             | basically at the root of the anti-intellectualism movement
             | right now (other than the standard hyper-fundamentalist
             | Christians that need to convince people that science in
             | general is all fraud), everyone sees all these wild claims
             | and conclusions made by "science journalists" with zero
             | scientific training and literal university PR departments
             | that are trivially disproved in the layman's mind simply by
             | the fact that they don't happen, and they lose faith not in
             | the journalists who have no idea what they are writing
             | about, but in _science itself_
             | 
             | I used to love Popular Science magazine in middle school,
             | but by high school I had noticed how much it's claims were
             | hyperbole and outright nonsense. I can't fathom how or why,
             | but most people blame the scientists for it.
             | 
             | Puffery is not a victimless crime.
        
         | qnleigh wrote:
         | This is a viable interpretation of quantum mechanics, but
         | currently there is no way to scientifically falsify or confirm
         | any particular interpretation. The boundary between philosophy
         | and science is fuzzy at times, but this question is solidly on
         | the side of philosophy.
         | 
         | That being said, I think the two most commonly preferred
         | interpretations of quantum mechanics among physicists are 'Many
         | Worlds' and 'I try not to think about it too hard.'
        
         | m3kw9 wrote:
         | So are we now concerned with the environment of another
         | universe? Like climate activitist but for multiverses?
        
         | whoitwas wrote:
         | Well. If you study quantum physics and the folks who found it
         | like Max Planck, they believed in "a conscious and intelligent
         | non-visible living energy force .. . the matrix mind of all
         | matter".
         | 
         | I don't know much about multiverse, but we need something
         | external to explain the magic we uncover.
         | 
         | Energy and quantum mechanics are really cool but dense to get
         | into. Like Planck, I suspect there's a link between
         | consciousness and matter. I also think our energy doesn't cease
         | to exist when our human carcass expires.
        
       | htrp wrote:
       | 105 qubits
        
       | wslh wrote:
       | ELI5: what I could do if I have this chip at home?
        
         | wrsh07 wrote:
         | Probably just research on quantum computers? I don't think it's
         | big enough to let you solve any practical problems, but maybe
         | someone can correct me
        
           | d3m0t3p wrote:
           | IF (and that's a big if) that's true then it means they can
           | factorize number into primes with this quantum computer and
           | break encryption.
        
             | Ar-Curunir wrote:
             | No, this quantum computer cannot factorize the large
             | composite numbers that we use for modern RSA. Even for the
             | numbers that it _can_ factor, I don 't think it will be
             | faster than a decent classical computer.
        
             | wasabi991011 wrote:
             | No, that's not what that means.
             | 
             | Not sure what you mean by the "that" when you say "if
             | that's true", but there is nothing in this thread or by
             | google that is anywhere close to breaking encryption.
        
               | bluSCALE4 wrote:
               | How are you so sure? If something that takes years is
               | completed in minutes, how is encryption safe?
        
               | shawabawa3 wrote:
               | The amount of cubits required for a practical application
               | of shors algorithm to break modern encryption is known
               | and it's around 2500 qubits
               | 
               | Willow has 100
        
               | wasabi991011 wrote:
               | Because the "something" in question is not decryption.
               | It's actually specifically something with no useful
               | result, just a benchmark.
               | 
               | Decryption with quantum computers is still likely decades
               | away, as others have pointed out.
               | 
               | To be specific, the best know quantum factoring did 15 =
               | 3x5, and when 35 was not able to be factored when
               | attempted. Most experimental demonstrations have stopped
               | in recent years due to how pointless it currently is.
        
       | readyplayernull wrote:
       | > It lends credence to the notion that quantum computation occurs
       | in many parallel universes, in line with the idea that we live in
       | a multiverse, a prediction first made by David Deutsch.
       | 
       | Processing in multiverse. Would that mean we are inyecting
       | entropy into those other verses? Could we calculate how many are
       | there from the time it takes to do a given calculation? We need
       | to cool the quantum chip in our universe, how are the (n-1)verses
       | cooling on their end?
        
         | deanCommie wrote:
         | What if we are? And by injecting entropy into it, we are
         | actually hurrying (in small insignificant ways) the heat death
         | of those universes? What if we keep going and scale out and in
         | the future it causes a meaningful impact to that universe in a
         | way that it's residents would be extremely unhappy with, and
         | would want to take revenge?
         | 
         | What if it's already happening to our universe? And that is
         | what black holes are? Or other cosmology concepts we don't
         | understand?
         | 
         | Maybe a great filter is your inability to protect your universe
         | from quantum technology from elsewhere in the multiverse
         | ripping yours up?
         | 
         | Maybe the future of sentience isn't fighting for resources on a
         | finite planet, or consuming the energy of stars, but fighting
         | against other multiverses.
         | 
         | Maybe The Dark Forest Defence is a decision to isolate your
         | universe from the multiverse - destroying it's ability to
         | participate in quantum computation, but also extending it's
         | lifespan.
         | 
         | (I don't believe ANY of this, but I'm just noting the
         | fascinating science fiction storylines available)
        
           | navaati wrote:
           | Getting strong vibes of Asimov's novel "The Gods Themselves"
           | here ! For those who haven't read it I recommend it. It's a
           | nice little self-contained book, not a grandiose series and
           | universe, but I love it.
        
             | demaga wrote:
             | This is exactly it, love that book.
        
           | kridsdale1 wrote:
           | I'd say it's more akin to Dark Energy than anything Black
           | Hole related.
           | 
           | DE is some sort of entropy that is being added to our cosmos
           | in an exponential way over historic time. It began at a point
           | a few billion in to our history.
        
           | Willish42 wrote:
           | Thanks for throwing in references like
           | https://en.wikipedia.org/wiki/Dark_forest_hypothesis even
           | though this was a silly response to the science fiction
           | implications.
           | 
           | I found it an interesting read and hadn't heard the term
           | before, but it's exactly the kind of nerdy serendipity I come
           | to this site for!
        
         | jsvlrtmred wrote:
         | AFAIK a fundamental step in any quantum computing algorithm is
         | bringing the qubits back to a state with a nonrandom outcome
         | (specifically, the answer to the problem being solved). Thus a
         | "good" quantum computer does not bifurcate the wavefunction at
         | a macro level, ie there is no splitting of the "multiverse"
         | after the calculation.
        
         | thrance wrote:
         | The many-worlds interpretation of quantum theory [1] is widely
         | considered unfalsifiable and therefore mostly pseudoscientific.
         | This article is way in over it's head in claiming such
         | nonsense.
         | 
         | [1] https://en.wikipedia.org/wiki/Many-worlds_interpretation
        
           | zarzavat wrote:
           | That depends on whether you think that MWI is making claims
           | beyond what QM claims, or if you think that MWI is just a
           | restatement of QM from another perspective. If the latter
           | then the falsifiability of MWI is exactly the same as the
           | falsifiability of QM itself.
        
           | newsbinator wrote:
           | Unfalsifiable does not mean pseudoscientific. Plenty of
           | things might be unfalsifiable for humans (e.g. humans lack
           | the cognitive capacity to conceive of ways to falsify them),
           | but then easily falsifiable for whatever comes after humans.
        
         | akira2501 wrote:
         | Isn't it really just processing with matrices of imaginary
         | numbers? Which is why you need error correction in the first
         | place because the higher temperature the system the less
         | coherent the phases all become? Thus having absolutely nothing
         | to do with multiverse theory?
         | 
         | I think string theories ideas about extra curled up dimensions
         | are far more likely places to look. You've already got an
         | infinite instantaneous energy problem with multiverses let
         | alone entropy transfer considerations.
        
       | ipsum2 wrote:
       | They renamed quantum supremacy to "beyond-classical"? That's
       | something.
        
         | maxboone wrote:
         | https://arxiv.org/abs/1705.06768
         | 
         | It's not something that new, I like it.
        
         | sdenton4 wrote:
         | Quantum supremacy was an absolutely awful name for what it was
         | (ability to do something, anything, better than a classical
         | computer, which remains 'supreme' on all problems of any
         | practical interest).
        
           | airstrike wrote:
           | Sure, but it sounded much cooler
        
       | Mistletoe wrote:
       | In what ways could Google monetize quantum computing?
        
         | michaelt wrote:
         | Searching through an unstructured data set of size N on a
         | classical computer takes O(N) time
         | 
         | but on a quantum computer, Grover's Algorithm allows such a
         | search to be performed in O(N^0.5) time.
         | 
         | So Quantum Computing, could bring us a future where, when you
         | perform a Google search for a word, the web pages returned
         | actually contain the word you searched for.
        
           | _benj wrote:
           | > So Quantum Computing, could bring us a future where, when
           | you perform a Google search for a word, the web pages
           | returned actually contain the word you searched for.
           | 
           | Lol! I'm not gonna put a kagi plug here...
        
       | 7e wrote:
       | Quantum mechanics is a computational shortcut that makes our
       | simulation cost-effective. Mass adoption of chips like these is
       | going to make the particular situation we live in unprofitable
       | for hosts, resulting in the firey and dramatic end of the world
       | for us. Simulating ancestors is fun, but not after your cloud
       | bill skyrockets. Thank you, Google, for bringing about the
       | apocalypse.
        
       | vessenes wrote:
       | I'm a quantum dabbler so I'll throw out an armchair reaction:
       | this is a significant announcement.
       | 
       | My memory is that 256 bit keys in non quantum resistant algos
       | need something like 2500 qubits or so; and by that I mean
       | generally useful programmable qubits. To show a bit over 100
       | qubits with stability, meaning the information survives a while,
       | long enough to be read, and general enough to run some benchmarks
       | on is something many people thought might never come.
       | 
       | There's a sort of religious reaction people have to quantum
       | computing: it breaks so many things that I think a lot of people
       | just like to assume it won't happen: too much in computing and
       | data security will change -> let's not worry about it.
       | 
       | Combined with the slow pace of physical research progress
       | (Schorrs algorithm for quantum factoring was mid 90s), and snake
       | oil sales companies, it's easy to ignore.
       | 
       | Anyway seems like the clock might be ticking; AI and data
       | security will be unalterably different if so. Worth spending a
       | little time doing some long tail strategizing I'd say.
        
         | goatking wrote:
         | How can I, a regular software engineer, learn about quantum
         | computing without having to learn quantum theory?
         | 
         | > Worth spending a little time doing some long tail
         | strategizing I'd say
         | 
         | any tips for starters?
        
           | sshb wrote:
           | Might be worth checking out: https://quantum.country/
        
           | zitterbewegung wrote:
           | I recommend this book I studied it in Undergrad and I never
           | took a quantum theory course. https://www.amazon.com/Quantum-
           | Computing-Computer-Scientists...
        
             | raidicy wrote:
             | Are there any insights that you can give based off the info
             | you've learned about quantum computation that you might not
             | have been able to reach if you hadn't learned about it?
             | 
             | From my __very__ shallow understanding, because all of the
             | efficiency increases are in very specific areas, it might
             | not be useful for the average computer science interested
             | individual?
        
               | zitterbewegung wrote:
               | Nearly all of quantum computation is theoretical
               | algorithms and the hard engineering problems haven't been
               | solved. Most of the math though has a large amount of
               | overlap of AI / ML and all of deep learning to the point
               | that Quantum computers could be used as "ML accelerators"
               | by using algorithms (this is called Quantum Machine
               | learning) [1]. Quantum computing could be learned with a
               | limited understanding of Quantum theory unless you are
               | trying to engineer the hardware.
               | 
               | https://en.wikipedia.org/wiki/Quantum_machine_learning
        
               | kvathupo wrote:
               | Possibly of interest, but I wrote a (hopefully
               | approachable) report on quantum perceptrons a few years
               | back [1]. Perhaps it's found elsewhere, but I was
               | surprised by how, at least in this quantum algo's case,
               | the basis of training was game theoretic not gradient
               | descent!
               | 
               | [1] - https://kvathupo.github.io/cs/quantum/457_Final_Rep
               | ort.pdf
        
           | potsandpans wrote:
           | Start here: https://youtu.be/F_Riqjdh2oM
           | 
           | You don't need to know quantum theory necessarily, but you
           | will need to know some maths. Specifically linear algebra.
           | 
           | There are a few youtube courses on linear algebra
           | 
           | For a casual set of video: - https://youtube.com/playlist?lis
           | t=PLZHQObOWTQDPD3MizzM2xVFit...
           | 
           | For a more formal approach:
           | 
           | - https://youtube.com/playlist?list=PL49CF3715CB9EF31D
           | 
           | And the corresponding open courseware
           | 
           | - https://ocw.mit.edu/courses/18-06-linear-algebra-
           | spring-2010...
           | 
           | Linear algebra done right comes highly recommended
           | 
           | - https://linear.axler.net/
        
             | RossBencina wrote:
             | +1 for 18-06 and Axler. Another, more concrete, option (not
             | sure how much it will help with quantum theory) is Stephen
             | Boyd's "Introduction to Applied Linear Algebra" available
             | online here:
             | 
             | https://web.stanford.edu/~boyd/vmls/
        
             | pagekicker wrote:
             | Isn't there a Python library that abstracts most of it away
             | with a couple of gigantic classes with incompatible
             | dependencies?
        
           | jvanderbot wrote:
           | There is a course mentioned in the article, but I'm not clear
           | on how "theory" it is.
           | 
           | https://coursera.org/learn/quantum-error-correction
        
           | carabiner wrote:
           | First learn about eigenvalues.
        
           | billti wrote:
           | If you're a software engineer, then the Quantum Katas might
           | fit your learning style. The exercises use Q#, which is
           | quantum specific programming language.
           | 
           | https://quantum.microsoft.com/en-us/tools/quantum-katas
           | 
           | The first few lessons do cover complex numbers and linear
           | algebra, so skip ahead if you want to get straight to the
           | 'quantum' coding, but there's really no escaping the math if
           | you really want to learn quantum.
           | 
           | Disclaimer: I work in the Azure Quantum team on our Quantum
           | Development Kit (https://github.com/microsoft/qsharp) -
           | including Q#, the Katas, and our VS Code extension. Happy to
           | answer any other questions on it.
        
             | auto wrote:
             | Is there a reasonable pivot for someone well versed in the
             | software engineering space to get in, or is it still the
             | playground of relevant Ph.Ds and the like? I've been up and
             | down the stack from firmware to the cloud, going on 14
             | years in the industry, have a Master's in CS, am the
             | technical lead for a team, yada yada, but have been
             | flirting with the idea of getting out of standard product
             | development and back into the nitty gritty of the space I
             | first pursued during undergrad.
        
               | almostgotcaught wrote:
               | > Is there a reasonable pivot for someone well versed in
               | the software engineering space to get in, or is it still
               | the playground of relevant Ph.Ds and the like?
               | 
               | there's no such thing as a practical QC and there won't
               | be for decades. this isn't a couple of years away - this
               | is "maybe, possibly, pretty please, if we get lucky"
               | 25-50 years away. find the above comment that alludes to
               | "2019 estimates needing ~20 million physical qubits" and
               | consider that this thing has 105 physical qubits. then
               | skim the posted article and find this number
               | 
               | > the key quantum computational resource -- are now
               | approaching 100 us (microseconds)
               | 
               | that's how long those 105 physical qubits stay coherent
               | for. now ponder your career pivot.
               | 
               | source: i dabbled during my PhD - took a couple of
               | classes from Fred Chong, wrote a paper - it's all hype.
        
           | kvathupo wrote:
           | The bar for entry is surprisingly low, you just need to brush
           | up on intro abstract algebra. I recommend the following:
           | 
           | 1. Kaye, LaFlamme, and Mosca - An Introduction to Quantum
           | Computing
           | 
           | 2. Nielsen and Chuang - Quantum Computation and Quantum
           | Information (The Standard reference source)
           | 
           | 3. Andrew Childs's notes here [1]. Closest to the state-of-
           | the-art, at least circa ~3 years ago.
           | 
           | [1] - https://www.cs.umd.edu/~amchilds/qa/
        
           | neoden wrote:
           | These lessons might be of help:
           | https://youtu.be/3-c4xJa7Flk?si=krrpXMKh3X5ktrzT
        
           | currymj wrote:
           | specifically avoid resources written by and for physicists.
           | 
           | the model of quantum mechanics, if you can afford to ignore
           | any real-world physical system and just deal with abstract
           | |0>, |1> qubits, is relatively easy. (this is really funny
           | given how incredibly difficult actual quantum physics can
           | be.)
           | 
           | you have to learn basic linear algebra with complex numbers
           | (can safely ignore anything really gnarly).
           | 
           | then you learn how to express Boolean circuits in terms of
           | different matrix multiplications, to capture classical
           | computation in this model. This should be pretty easy if you
           | have a software engineer's grasp of Boolean logic.
           | 
           | Then you can learn basic ideas about entanglement, and a few
           | of the weird quantum tricks that make algorithms like Shor
           | and Grover search work. Shor's algorithm may be a little
           | mathematically tough.
           | 
           | realistically you probably will never need to know how to
           | program a quantum computer even if they become practical and
           | successful. applications are powerful but very limited.
           | 
           | "What You Shouldn't Know About Quantum Computers" is a good
           | non-mathematical read.
           | 
           | https://arxiv.org/abs/2405.15838
        
           | ajb wrote:
           | The simplest algorithm to understand is probably Grover's
           | algorithm. Knowing that shows you how to get an sqrt(N)
           | speedup on many classical algorithms. Then have a look at
           | shor's algorithm which is the classic factoring algorithm.
           | 
           | I would not worry about hardware at first. But if you are
           | interested and like physics, the simplest to understand are
           | linear optical quantum circuits. These use components which
           | may be familiar from high school or undergraduate physics.
           | The catch is that the space (and component count) is
           | exponential in the number of qubits, hence the need for more
           | exotic designs.
        
           | cevi wrote:
           | I always recommend Watrous's lecture notes:
           | https://cs.uwaterloo.ca/~watrous/QC-notes/QC-notes.pdf
           | 
           | I prefer his explanation to most other explanations because
           | he starts, right away, with an analogy to ordinary
           | probabilities. It's easy to understand how linear algebra is
           | related to probability (a random combination of two outcomes
           | is described by linearly combining them), so the fact that we
           | represent random states by vectors is not surprising at all.
           | His explanation of the Dirac bra-ket notation is also
           | extremely well executed. My only quibble is that he doesn't
           | introduce density matrices (which in my mind are the correct
           | way to understand quantum states) until halfway through the
           | notes.
        
           | tsimionescu wrote:
           | If you want to learn about what theoretical quantum computers
           | might be able to do faster than classical ones and what they
           | might not, you can try to read about quantum complexity
           | theory, or some of what Scott Aaronson puts out on his blog
           | if you don't want to go that in depth.
           | 
           | But the key thing to know about quantum computing is that it
           | is all about the mathematical properties of quantum physics,
           | such as the way complex probabilities work.
        
         | thrance wrote:
         | The error rates given are still horrendous and nowhere near low
         | enough for the Quantum Fourier Transform used by Shor's
         | algorithm. Taking qubit connectivity into account, a single CX
         | between 2 qubits that are 10 edges aways gives an error rate of
         | 1.5%.
         | 
         | Also, the more qubits you have/the more instructions are in
         | your program, the faster the quantum state collapses.
         | Exponentially so. Qubit connectivity is still ridiculously low
         | (~3) and does not seem to be improving at all.
         | 
         | About AI, what algorithm(s) do you think might have an edge
         | over classical supercomputers in the next 30 years? I'm really
         | curious, because to me it's all (quantum) snake oil.
        
           | LeftHandPath wrote:
           | Re: AI, it's a long way off still. The big limitation to
           | anything quantum is always going to be decoherence and t-time
           | [0]. To do anything with ML, you'll need whole circuit (more
           | complex than shor's) just to initialize the data on the
           | quantum device; the algorithms to do this are complex
           | (exponential) [1]. So, you have to run a very expensive data-
           | initialization circuit, and only then can you start to run
           | your ML circuit. All of this needs to be done within the
           | machine's t-time limit. If you exceed that limit, then the
           | measured state of a qubit will have more to do with outside-
           | world interactions than interactions with your quantum gates.
           | 
           | Google's willow chip has t-times of about 60-100mu.s. That's
           | not an impressive figure -- in 2022, IBM announced their
           | Eagle chip with t-times of around 400mu.s [2]. Google's angle
           | here would be the error correction (EC).
           | 
           | The following portion from Google's announcement seems most
           | important:
           | 
           | > With 105 qubits, Willow now has best-in-class performance
           | across the two system benchmarks discussed above: quantum
           | error correction and random circuit sampling. Such
           | algorithmic benchmarks are the best way to measure overall
           | chip performance. Other more specific performance metrics are
           | also important; for example, our T1 times, which measure how
           | long qubits can retain an excitation -- the key quantum
           | computational resource -- are now approaching 100 us
           | (microseconds). This is an impressive ~5x improvement over
           | our previous generation of chips.
           | 
           | Again, as they lead with, their focus here is on error
           | correction. I'm not sure how their results compare to
           | competitors, but it sounds like they consider that to be the
           | biggest win of the project. The RCS metric is interesting,
           | but RCS has no (known) practical applications (though it is a
           | common benchmark). Their T-times are an improvement over
           | older Google chips, but not industry-leading.
           | 
           | I'm curious if EC can mitigate the sub-par decoherence times.
           | 
           | [0]: https://www.science.org/doi/abs/10.1126/science.270.5242
           | .163...
           | 
           | [1]: https://dl.acm.org/doi/abs/10.5555/3511065.3511068
           | 
           | [2]: https://www.ibm.com/quantum/blog/eagle-quantum-
           | processor-per...
        
             | wasabi991011 wrote:
             | > I'm curious if EC can mitigate the sub-par decoherence
             | times.
             | 
             | The main EC paper referenced in this blog post showed that
             | the logical qubit lifetime using a distance-7 code (all 105
             | qubits) was double the lifetime of the physical qubits of
             | the same machine.
             | 
             | I'm not sure how lifetime relates to decoherence time, but
             | if that helps please let me know.
        
               | LeftHandPath wrote:
               | That's very useful, I missed that when I read through the
               | article.
               | 
               | If the logical qubit can have double the lifetime of any
               | physical qubit, that's massive. Recall IBM's chips, with
               | t-times of ~400microseconds. Doubling that would change
               | the order of magnitude.
               | 
               | It still won't be enough to do much in the near term -
               | like other commenters say, this seems to be a proof of
               | concept - but the concept is very promising.
               | 
               | The first company to get there and make their systems
               | easy to use could see a similar run up in value to NVIDIA
               | after ChatGPT3. IBM seems to be the strongest in the
               | space overall, for now.
        
               | deepburner wrote:
               | I'm sorry if this is nitpicky but your comment is
               | hilarious to me - doubling something is doubling
               | something, "changing the order of magnitude" would entail
               | multiplication by 10.
        
               | LeftHandPath wrote:
               | Hahaha not at all, great catch. Sometimes my gray matter
               | just totally craps out... like thinking of "changing
               | order of magnitude" as "adding 1 extra digit".
               | 
               | Reminds me of the time my research director pulled me
               | aside for defining CPU as "core processing unit" instead
               | of "central processing unit" in a paper!
        
             | JanisErdmanis wrote:
             | Wouldn't thoose increased decoherence times need to be
             | viewed in relation to the time it takes to execute a basic
             | gate? If the time to execute a gate also increases it may
             | overtake practicality of having less noisy logical qubits.
        
           | AlexCoventry wrote:
           | In addition to that, the absolutely enormous domains that the
           | Fourier Transform sums over (essentially, one term in the sum
           | for each possible answer), and the cancellations which would
           | have to occur for that sum to be informative, means that a
           | theoretically-capable Quantum Computer will be testing the
           | predictions of Quantum Mechanics to a degree of precision
           | hundreds of orders of magnitude greater than any physics
           | experiment to date. (Or at least dozens of orders of
           | magnitude, in the case of breaking Discrete Log on an
           | Elliptic Curve.) It demands higher accuracy in the
           | probability distributions predicted by QM than could be
           | confirmed by naive frequency tests which used the entire
           | lifetime of the entire universe as their laboratory!
           | 
           | Imagine a device conceived in the 17th century, the intended
           | functionality of which would require a physical sphere which
           | matches a perfect, ideal, geometric sphere in Euclidean space
           | to thousands of digits of precision. We now know that the
           | concept of such a perfect physical sphere is incoherent with
           | modern physics in a variety of ways (e.g., atomic basis of
           | matter, background gravitational waves.) I strongly suspect
           | that the cancellations required for the Fourier Transform in
           | Shor's algorithm to be cryptographically relevant will turn
           | out to be the moral equivalent of that perfect sphere.
           | 
           | We'll probably learn some new physics in the process of
           | trying to build a Quantum Computer, but I highly doubt that
           | we'll learn each others' secrets.
        
             | JanisErdmanis wrote:
             | Beautiful analogy.
        
           | sesm wrote:
           | > Also, the more qubits you have/the more instructions are in
           | your program, the faster the quantum state collapses.
           | 
           | Was this actually measured and published somewhere?
        
         | JanisErdmanis wrote:
         | The required number of qubits to execute Shor's algorithm is
         | way larger than 2500 qubits as the error ceiling for logical
         | qubits must decrease exponentially with every logical qubit
         | added to produce meaningful results. Hence, repeated
         | applications of error correction or an increase in the surface
         | code would be required. That would significantly blow up the
         | number of physical qubits needed.
        
           | adastra22 wrote:
           | He's quoting the number of logical qubits (which is 1024
           | IIRC, not 2500), after error correction.
           | 
           | ETA: Wikipedia 2330 qubits, but I'm not sure it is citing the
           | most recent work: https://en.wikipedia.org/wiki/Elliptic-
           | curve_cryptography#ci...
        
             | pclmulqdq wrote:
             | 1024 is for RSA-1024, which is believed to be broken by
             | classical means at this point. Everyone doing anything with
             | RSA is on 4k or larger.
        
               | Vecr wrote:
               | They are? The short term recommendation is 3072, and I
               | still see lots of 2048. Actually, it's mostly 2048.
        
               | wcoenen wrote:
               | > _Everyone doing anything with RSA is on 4k or larger._
               | 
               | The Let's Encrypt intermediate certificates R10 and R11
               | seem to be only 2048 bit.
        
               | pclmulqdq wrote:
               | A signature (not encryption) with short-term valid life
               | is fine at 2048 still.
        
               | adastra22 wrote:
               | I took this conversation to be about ECC, not RSA.
        
               | notarealllama wrote:
               | My completely unfounded tin foil hat at the moment is
               | that ECC was pushed as a standard not because it was
               | faster/ smaller, but the smaller bit size makes it less
               | quantum resistant and is more prone to be broken first
               | (if not already) via quantum supremacy.
        
               | tptacek wrote:
               | You're right, that's pretty unfounded.
        
               | marcosdumay wrote:
               | ECC is easier to implement right. Even the older ones
               | that are full of footguns have orders of magnitude less
               | footguns than RSA.
               | 
               | So don't fear them due to unfounded theories.
        
               | anonymoushn wrote:
               | Is there consensus on what signature validation is
               | correct?
               | https://hdevalence.ca/blog/2020-10-04-its-25519am
        
               | marcosdumay wrote:
               | IMO, that article has a clear conclusion that you should
               | aim your software at the libsodium-1.0.16 pattern (no
               | edge cases).
               | 
               | The problem it's presenting is more about software on the
               | wild having different behavior... And if "some people
               | connect on the internet and use software that behaves
               | differently from mine" is a showstopper for you, I have
               | some really bad news.
        
               | pclmulqdq wrote:
               | Discrete log doesn't use Shor's algorithm, and appears to
               | need more qubits to break (per key bit).
        
               | tptacek wrote:
               | 2048. There is no plausible conventional attack on 2048;
               | whatever breaks 2048 is probably going to break 4096, as
               | I understand it.
               | 
               | https://crypto.stackexchange.com/questions/1978/how-big-
               | an-r...
        
               | FredF--- wrote:
               | Is it broken? Seems still no one solved RSA-1024
               | challenge.
        
               | pclmulqdq wrote:
               | The state actors aren't going to reveal their
               | capabilities by solving an open challenge.
        
               | rob-olmos wrote:
               | Reminder to anyone if DKIM keys haven't been rotated in a
               | while they might still be 1024. Eg., Google Workspace but
               | new keys are 2048 now.
        
             | JanisErdmanis wrote:
             | I actually thought the number of logical qubits needed was
             | around 20 for factorisation as the state space size is
             | 2^(2^n) and hence did not recognise them as the number of
             | logical qubits required. It is often misunderstood that
             | error correction needs to be done only once, as with
             | classical quantum computers, and the numbers would fit
             | together with one pass of error correction.
             | 
             | The Shor's algorithm requires binary encoding; hence, 2048
             | logical qubits are needed to become a nuance for
             | cryptography. This, in turn, means that one will always be
             | easily able to run away from a quantum adversary by paying
             | a polynomial price on group element computations, whereas a
             | classical adversary is exponentially bounded in computation
             | time, and a quantum adversary is exponentially bounded with
             | a number of physical qubits. Fascinating...
        
             | Strilanc wrote:
             | The most recent result on reducing the number of logical
             | qubits is [1]. They show how to use residue arithmetic to
             | factor n bit numbers using n/2 + o(n) logical qubits (they
             | give the example of 1730 qubits to factor a 2048 bit
             | number).
             | 
             | [1]: https://eprint.iacr.org/2024/222
        
           | The5thElephant wrote:
           | Isn't that what they are claiming is true now? That the
           | errors do decrease exponentially with each qubit added?
        
             | JanisErdmanis wrote:
             | What they claim is that adding physical qubits reduce error
             | rate of the logical qubits exponentially. For the Schor
             | algorithm the error rate of the logical qubits must
             | decrease exponentially with every single logical qubit
             | added to make the system produce meaningful results.
             | 
             | To see how it plays out consider adding a single logical
             | qubit. First you need to increase the number of physical
             | qubits to accommodate the new logical qubit at the same
             | error rate. Then multiply the number of physical qubits to
             | accommodate for exponentially decreased error rate which
             | would be a constant factor N ( or polynomial but let's keep
             | things simple) by which the number of physical qubits need
             | to be multiplied to produce a system with one additional
             | logical qubit with an error rate to produce meaningful
             | results.
             | 
             | To attain 1024 logical qubits for Schor algorithm one would
             | need N^1024 physical qubits. The case where N<1 would be
             | possible if error would decrease by itself without
             | additional error correction.
        
         | isoprophlex wrote:
         | Data security okay. But AI? How will that change?
        
           | adastra22 wrote:
           | AI is essentially search. Quantum computers are really good
           | at search.
        
             | sheeshkebab wrote:
             | Search of what?
        
               | roywiggins wrote:
               | Latent space?
               | 
               | https://en.wikipedia.org/wiki/Latent_space
        
               | adastra22 wrote:
               | Anything. Everything. In domains where the search space
               | is small enough to physically enumerate and store or
               | evaluate every option, search is commonly understood as a
               | process solved by simple algorithms. In domains where the
               | search space is too large to physically realize or index,
               | search becomes "intelligence."
               | 
               | E.g. winning at Chess or Go (traditional AI domains) is
               | searching through the space of possible game states to
               | find a most-likely-to-win path.
               | 
               | E.g. an LLM chat application is searching through
               | possible responses to find one which best correlates with
               | expected answer to the prompt.
               | 
               | With Grover's algorithm, quantum computers let you find
               | an answer in any disordered search space with O(sqrt(N))
               | operations instead of O(N). That's potentially applicable
               | to many AI domains.
               | 
               | But if you're so narrow minded as to only consider
               | connectionist / neural network algorithms as "AI", then
               | you may be interested to know that quantum linear algebra
               | is a thing too:
               | https://en.wikipedia.org/wiki/HHL_algorithm
        
               | cwillu wrote:
               | O(sqrt(N)) is easily dominated by the relative ease of
               | constructing much bigger classical computers though.
        
               | adastra22 wrote:
               | Uh, no? Not for large N.
               | 
               | There are about 2^152 possible legal chess states. You
               | cannot build a classical computer large enough to compute
               | that many states. Cryptography is generally considered
               | secure when it involves a search space of only 2^100
               | states.
               | 
               | But you could build a computer to search though
               | sqrt(2^152) = 2^76 states. I mean it'd be big--that's on
               | the order of total global storage capacity. But not
               | "bigger than the universe" big.
        
               | IanCal wrote:
               | Doing 2^76 iterations is _huge_. That 's a trillion
               | operations a second for two and a half thousand years if
               | I've not slipped up and missed a power of ten.
        
               | hatthew wrote:
               | Maybe 100 years from now we can do 2^18 quantum ops/sec
               | and solve chess in a day, whereas a classical computer
               | could do 2^36 ops/sec and still take longer than the
               | lifetime of the universe to complete.
        
               | adastra22 wrote:
               | Google's SHA-1 collision took 2^63.1 hash operations to
               | find. Given that a single hash operation takes more than
               | 1000 cycles, that's only less than three doublings away.
               | 
               | Cryptographers worry about big numbers. 2^80 is not
               | considered secure.
        
               | IanCal wrote:
               | It's early so I'm thinking out loud here but I don't
               | think the algorithm scales like this, does it?
               | 
               | We're talking about something that can search a list of
               | size N in sqrt(N) iterations. Splitting the problem in
               | two doesn't halve the compute required for each half. If
               | you had to search 100 items on one machine it's taken 10x
               | iterations but split over two it'd take ~7x on each or
               | ~14 in total.
        
               | tsimionescu wrote:
               | If an algorithm has a complexity class of O(sqrt(N)), by
               | definition it means that it can do better if run on all
               | 100 elements than by splitting the list into two elements
               | and running it on each 50.
               | 
               | This is not at all a surprising property. The same things
               | happens with binary search: it has complexity O(log(N)),
               | which means that running it on a list of size 1024 will
               | take about 10 operations, but running it in parallel on
               | two lists of size 512 will take 2 * 9 operations = 18.
               | 
               | This is actually easy to intuit when it comes to search
               | problems: the element you're looking for is either in the
               | first half of the list or in the second half, it can't be
               | in both. So, if you are searching for it in parallel in
               | both halves, you'll have to do extra work that just
               | wasn't necessary (unless your algorithm is to look at
               | every element in order, in which case it's the same).
               | 
               | In the case of binary search, with the very first
               | comparison, you can already tell in which half of the
               | list your element is: searching the other half is
               | pointless. In the case of Grober's algorithm, the
               | mechanism is much more complex, but the basic point is
               | similar: Grover's algorithm has a way to just not look at
               | certain elements of the list, so splitting the list in
               | half creates more work overall.
        
               | CJefferson wrote:
               | No-one would solve chess by checking every possible legal
               | chess state -- also checking 'all the states' wouldn't
               | solve chess, you need a sequence of moves, and that
               | pushes you up to an even bigger number. But again, you
               | can easily massively prune that, as many moves are
               | forced, or you can check you are in a provable end-game
               | situation.
        
               | tsimionescu wrote:
               | That only helps for a relative small range of N. Chess
               | happens to sort of fit into this space. Go is way out,
               | even a sqrt(N) is still in the "galaxy-sized computer"
               | range. So again, there are few problems for which
               | Grover's algorithms really takes us from practically
               | uncomputable to computable.
               | 
               | Even for chess, 2^76 operations is still waaaaay more
               | time than anyone will ever wait for a computation to
               | finish, even if we assumed quantum computers could reach
               | the OPS of today's best classical computers.
        
               | CJefferson wrote:
               | Grover's algorithm is useful for very few things in
               | practice, because for most problems we have a better
               | technique than checking sqrt(N) of all possible
               | solutions, at least heuristicly.
               | 
               | There is, at present, no quantum algorithm which looks
               | like it would beat the state of the art on Chess, Go, or
               | NP-complete problems in general.
        
               | spencerchubb wrote:
               | training an ai model is essentially searching for
               | parameters that can make a function really accurate at
               | making predictions. in the case of LLMs, they predict
               | text.
        
             | cwillu wrote:
             | Unstructured search is only a [?]n improvement. You need to
             | find some way for algorithmically significant
             | interference/cancellation of terms in order for a qc to
             | potentially (!) have any benefit.
        
           | numpad0 wrote:
           | Aren't quantum computers expected to be like digitally read
           | analog computers for high dimension optimization problems,
           | and AI is like massive high dimension optimization problems?
        
             | Yoric wrote:
             | Google is betting on digital quantum computers.
             | 
             | There are, however, analog quantum computers, e.g. by
             | Pasqal, which hope to capitalize on this to optimize AI-
             | like high dimension optimization problems.
        
               | gecko22 wrote:
               | Why do quantum computers need to be analog to be applied
               | to such problems?
        
               | arlort wrote:
               | They don't, but if I interpreted the post above correctly
               | analog QCs aremuch easier to build
               | 
               | At least as far as I'm aware by digital they probably
               | mean a generally programmable QC, whereas another
               | approach is to encode a specific class of problems in the
               | physical structure of an analog QC so that it solves
               | those problems much faster than classical. This latter
               | approach is less general (so for instance you won't use
               | it to factor primes) but much more attainable. I think
               | D-wave or someone like that already had commercial
               | application for optimization problems (either traveling
               | salesman or something to do with port organization)
        
               | numpad0 wrote:
               | But aren't qubits sort of analog? I thought the bits have
               | figurative angles of rotation or something continuous
               | that would resonate together and/or cancel out like
               | neurons in fully-connected parts of neural nets that
               | would be read out at the end of the pipeline.
        
         | winwang wrote:
         | Edit after skimming arxiv preprint[1]:
         | 
         | Yeah, this is pretty huge. They achieved the result with
         | surface codes, which are general ECCs. The repetition code was
         | used to further probe quantum ECC floor. "Just POC" likely
         | doesn't do it justice.
         | 
         | (Original comment):
         | 
         | Also quantum dabbler (coincidentally dabbled in bitflip quantum
         | error correction research). Skimmed the post/research blog. I
         | believe the key point is the scaling of error correction via
         | repetition codes, would love someone else's viewpoint.
         | 
         | Slightly concerning quote[2]:
         | 
         | """
         | 
         | By running experiments with repetition codes and ignoring other
         | error types, we achieve lower encoded error rates while
         | employing many of the same error correction principles as the
         | surface code. The repetition code acts as an advance scout for
         | checking whether error correction will work all the way down to
         | the near-perfect encoded error rates we'll ultimately need.
         | 
         | """
         | 
         | I'm getting the feeling that this is more about proof-of-
         | concept, rather than near-practicality, but this is certainly
         | one fantastic POC if true.
         | 
         | [1]: https://arxiv.org/abs/2408.13687
         | 
         | [2]: https://research.google/blog/making-quantum-error-
         | correction...
         | 
         | Relevant quote from preprint (end of section 1, sorry for copy-
         | paste artifacts):
         | 
         | """
         | 
         | In this work, we realize surface codes operating below
         | threshold on two superconducting processors. Using a 72-qubit
         | processor, we implement a distance-5 surface code operating
         | with an integrated real-time decoder. In addition, using a
         | 105-qubit processor with similar performance, we realize a
         | distance-7 surface code. These processors demonstrate L > 2 up
         | to distance-5 and distance7, respectively. Our distance-5
         | quantum memories are beyond break-even, with distance-7
         | preserving quantum information for more than twice as long as
         | its best constituent physical qubit. To identify possible
         | logical error f loors, we also implement high-distance
         | repetition codes on the 72-qubit processor, with error rates
         | that are dominated by correlated error events occurring once an
         | hour. These errors, whose origins are not yet understood, set a
         | current error floor of 10-10. Finally, we show that we can
         | maintain below-threshold operation on the 72qubit processor
         | even when decoding in real time, meeting the strict timing
         | requirements imposed by the processor's fast 1.1us cycle
         | duration.
         | 
         | """
        
           | echelon wrote:
           | Google could put themselves and everyone else out of business
           | if the algorithms that underpin our ability to do e-commerce
           | and financial transactions can be defeated.
           | 
           | Goodbye not just to Bitcoin, but also Visa, Stripe, Amazon
           | shopping, ...
        
             | mperham wrote:
             | Right? Does TLS1.3 have the underpinnings to use quantum-
             | proof encryption algos?
             | 
             | https://en.wikipedia.org/wiki/Post-quantum_cryptography
             | 
             | https://www.microsoft.com/en-us/research/project/post-
             | quantu...
             | 
             | https://www.forbes.com/councils/forbestechcouncil/2024/10/0
             | 9...
        
               | bangaladore wrote:
               | It seems you can get TLS 1.3 (or atlest slighty modified
               | 1.3) to be quantum secure, but it increases the handshake
               | size by roughly 9x. Cloudflare unfortunately didn't
               | mention much about the other downsides though.
               | 
               | https://blog.cloudflare.com/kemtls-post-quantum-tls-
               | without-...
        
               | bwesterb wrote:
               | About one third of traffic with Cloudflare is already
               | using post-quantum encryption.
               | https://x.com/bwesterb/status/1866459174697050145
               | 
               | Signatures still have to be upgraded, but that's more
               | difficult. We're working on it.
               | http://blog.cloudflare.com/pq-2024/#migrating-the-
               | internet-t...
        
               | SAI_Peregrinus wrote:
               | Yes-ish. They're not enabled yet, but post-quantum
               | signatures & KEMs are available in some experimental
               | versions of TLS. None are yet standardized, but I'd
               | expect a final version well before QCs can actually break
               | practical signatures or key exchanges.
        
               | bwesterb wrote:
               | One third of all human traffic with Cloudflare is using a
               | post-quantum KEM. I'd say that counts as enabled. We want
               | that to be 100% of course. Chrome (and derivates) enabled
               | PQ by default. https://radar.cloudflare.com/adoption-and-
               | usage
        
             | bluSCALE4 wrote:
             | Why is no one else talking about this? I came here to see a
             | discussion about this and encryption.
        
               | wasabi991011 wrote:
               | Because this result is still very far from anything
               | related to practical decryption.
        
               | jgalt212 wrote:
               | And if they were, would they tell the world?
        
               | tsimionescu wrote:
               | If they had a QC that could run Shor's algorithm to
               | factor the number 1000, I'd guarantee you they'd tell the
               | whole world. And it would still be a long, _long_ time
               | from there to having a QC that can factor 2048-bit
               | numbers.
        
             | shriphani wrote:
             | bitcoin proof of work is not as impacted by quantum
             | computers - grover's algorithm provides a quadratic speedup
             | for unstructured search - so SHA256 ends up with 128 bits
             | of security for pre-image resistance. BTC can easily move
             | to SHA512.
             | 
             | symmetric ciphers would have similar properties (AES,
             | CHACHA20). Asymmetric encryption atm would use ECDH (which
             | breaks) to generate a key for use with symmetric ciphers -
             | Kyber provides a PQC KEM for this.
             | 
             | So, the situation isn't as bad. We're well positioned in
             | cryptography to handle a PQC world.
        
             | qnleigh wrote:
             | It's currently believed that quantum computers cannot break
             | all forms of public key cryptography. Lattice based
             | cryptography is a proposed replacement to RSA that would
             | let us keeping buying things online no problem.
        
           | wasabi991011 wrote:
           | You got the main idea, it's a proof-of-concept: that a class
           | of error-correcting code on real physical quantum chips obey
           | the threshold theorem, as is expected based on theory and
           | simulations.
           | 
           | However the main scaling of error correction is via surface
           | codes, not repetition codes. It's an important point as
           | surface codes correct all Pauli errors, not just either bit-
           | flips or phase-flips.
           | 
           | They use repetition codes as a diagnostic method in this
           | paper more than anything, it is not the main result.
           | 
           | In particular, I interpret the quote you used as: "We want to
           | scale surface codes even more, and if we were able to do the
           | same scaling with surface codes as we are able to do with
           | repetition codes, then this is the behaviour we would
           | expect."
           | 
           | Edit: Welp, saw your edit, you came to the same conclusion
           | yourself in the time it took me to write my comment.
        
             | winwang wrote:
             | Haha, classic race condition, but I appreciate your take
             | nonetheless!
        
         | bee_rider wrote:
         | I think some element of it might be: Shor's algorithm has been
         | known of for 30 years, and hypothetically could be used to
         | decrypt captured communications, right? So, retroactively I
         | will have been dumb for not having switched to a quantum-
         | resistant scheme. And, dumb in a way that a bunch of academic
         | nerds have been pointing out for decades.
         | 
         | That level of embarrassment is frankly difficult to face. And
         | it would be devastating to the self-image of a bunch of
         | "practical" security gurus.
         | 
         | Therefore any progress must be an illusion. In the real world,
         | the threats are predictable and mistakes don't slowly snowball
         | into a crisis. See also, infrastructure.
        
           | adastra22 wrote:
           | What would you switch to? There hasn't been post quantum
           | systems to use until very very recently.
        
           | bawolff wrote:
           | All you encrypted communication from the 90s (SSL anyways)
           | can probably be decrypted with classical means anyways. 90s
           | SSL was pretty bad.
        
         | cherryteastain wrote:
         | > AI and data security will be unalterably different if so
         | 
         | Definitely agree with the latter, but do you have any sources
         | on how quantum comphters make "AI" (i.e. matrix multiplication)
         | faster?
        
           | meta_x_ai wrote:
           | Exploring via Search can become O(1) instead of M^N
        
             | bawolff wrote:
             | That is definitely not true.
        
         | npalli wrote:
         | > Worth spending a little time doing some long tail
         | strategizing I'd say.
         | 
         | Yup, like Bitcoin going to zero.
        
           | drcode wrote:
           | eh, they will add a quantum-resistant signature scheme
           | (already a well-understood thing) then people can transfer
           | their funds to the new addresses before it is viable to crack
           | the existing addresses
        
             | bangaladore wrote:
             | So the first company that can break bitcoin addresses using
             | quantum computers gets a prize of how many billion(?)
             | dollars by stealing all the non-migrated addresses.
             | 
             | Is that a crime? Lots of forgotten keys in there.
        
               | webXL wrote:
               | A very interesting philosophical and moral can of worms
               | you just opened there. Bitcoin is governed by the
               | protocol, so if the protocol permits anyone who can sign
               | a valid transaction involving a given UTXO to another
               | address, then it technically isn't a "crime". Morally I'm
               | not sure I'd be able to sleep well at night if I
               | unilaterally took what I didn't exchange value for.
               | 
               | As for the forgotten key case, I think the only way to
               | prove you had the key at some point would need to involve
               | the sender vouching for you and cryptographically proving
               | they were the sender.
        
               | tsimionescu wrote:
               | Morally, there is no quandary: it's obviously morally
               | wrong to take someone else's things, and knowing their
               | private key changes nothing.
               | 
               | Legally, the situation is the same: legal ownership is
               | not in any way tied to the mechanism of how some system
               | or another keeps track of ownership. Your BTC is yours
               | via a contract, not because the BTC network says so. Of
               | course, proving to a judge that someone else stole your
               | BTC may be extremely hard, if not impossible.
               | 
               | Saying "if the protocol permits anyone who can sign a
               | valid transaction involving a given UTXO to another
               | address, then it technically isn't a "crime"" is like
               | saying "traditional banking is governed by a banker
               | checking your identity, so if someone can convince the
               | banker they are you, then it technically isn't a
               | "crime"".
               | 
               | The only thing that wouldn't be considered a crime, in
               | both cases, is the system allowing the transaction to
               | happen. That is, it's not a crime for the bank teller to
               | give your money to someone else if they were legitimately
               | fooled; and it's not a crime for the Bitcoin miners to
               | give your money to someone else if that someone else
               | impersonated your private key. But the person who fooled
               | the bank teller /the miners is definitely committing a
               | crime.
        
           | K0balt wrote:
           | I think you're going to need about 10,000,000 qbits to divert
           | a transaction, but that's still within foreseeable scale. I
           | think it's extreme likely that the foundation will have
           | finished their quantum resistance planning before we get to
           | 10MM coherent qbits, but still, it's a potential scenario.
           | 
           | More likely that other critical infrastructure failures will
           | happen within trad-finance, much larger vulnerability
           | footprint, and being able to trivially reverse engineer every
           | logged SSL session is likely to be a much more impactful turn
           | of events. I'd venture that there are significant ear-on-the-
           | wire efforts going on right now in anticipation of a
           | reasonable bulk SSL de cloaking solution. Right now we think
           | it doesn't matter who can see our "secure" traffic. I think
           | that is going to change, retroactively, in a big way.
        
             | vessenes wrote:
             | I agree that the scary scenario is stored SSL frames from
             | 20 years of banking. That's nuclear meltdown scenarios.
        
               | K0balt wrote:
               | It is.. and I don't see a way to avoid it.
        
               | kdmtctl wrote:
               | To do what? Replay? Just curious on an attack vector.
        
               | K0balt wrote:
               | Hopefully replay attacks will not be useful, but
               | confidential information will be abundant. There will be
               | actionable information mixed in there , and it will be a
               | lot of data. Just imagine if everything whispered
               | suddenly became shouted.
        
           | sekai wrote:
           | > Yup, like Bitcoin going to zero.
           | 
           | If the encryption on Bitcoin is broken, say goodbye to the
           | banking system.
        
             | nadahalli wrote:
             | [pedantic hat on] Bitcoin doesn't use encryption.
             | 
             | You mean digital signatures - and yes, we use signatures
             | everywhere in public key cryptography.
        
             | socks wrote:
             | not really. banking systems have firewalls and access
             | controls. quantum computations would be useless.
        
               | webXL wrote:
               | Those don't really mean anything when an attacker can
               | eavesdrop on customer and employee comms and possibly
               | redirect transactions (MITM).
        
               | kelnos wrote:
               | Banking communications and transactions will all be
               | protected by quantum-resistant protocols and ciphers well
               | before that will become a problem. Most of these already
               | exist, and some of them can even be deployed.
        
           | vessenes wrote:
           | I'm a _little_ more in my wheelhouse here -- without an algo
           | change, Grover 's algorithm would privilege quantum miners
           | significantly, but not any more than the industry has seen in
           | the last 13 years (C code on CPU -> GPU -> Large Geometry
           | ASIC -> Small Geometry ASIC are similarly large shifts in
           | economics for miners probably).
           | 
           | As to faking signatures and, e.g. stealing Satoshi's coins or
           | just fucking up the network with fake transactions that
           | verify, there is some concern and there are some attack
           | vectors that work well if you have a large, fast quantum
           | computer and want to ninja in. Essentially you need something
           | that can crack a 256 bit ECDSA key before a block that
           | includes a recently released public key can be inverted.
           | That's definitely out of the reach of anyone right now, much
           | less persistent threat actors, much less hacker hobbyists.
           | 
           | But it won't always be. The current state of the art plan
           | would be to transition to a quantum-resistant UTXO format,
           | and I would imagine, knowing how Bitcoin has managed itself
           | so far, that will be a well-considered, very safe, multi-year
           | process, and it will happen with plenty of time.
        
             | ravenhappy wrote:
             | You fool! And I say that affectionately. Another fool says:
             | the security of Bitcoin relies on the inability to (among
             | other things) derive a private key from a public key. This
             | is just basic cryptography, like Turning vs enigma. This
             | machine can "calculate" solutions to problems in time
             | frames that break the whole way that cryptocurrency works.
             | You better believe that what we hear about is old. These
             | types of systems, and there must be non-public versions,
             | could solve a private key from a public key, in easy less
             | than O(fu) time.
             | 
             | EDIT: it's like rainbow hashes, but every possible
             | variation is a color, not granular like binary, but all and
             | any are included.
        
           | m101 wrote:
           | Bitcoin will just fork to a quantum proof encryption scheme
           | and there will be something called "bitcoin classic" that is
           | the old protocol (which few would care about)
        
         | qnleigh wrote:
         | You need to distinguish between "physical qubits" and "logical
         | qubits." This paper creates a single "first-of-a-kind" logical
         | qubit with about 100 physical qubits (using Surface Code
         | quantum error correction). A paper from Google in 2019
         | estimates needing ~20 million physical qubits ("How to factor
         | 2048 bit RSA integers in 8 hours using 20 million noisy qubits"
         | - https://arxiv.org/abs/1905.09749), though recent advances
         | probably brought this number down a bit. That's because to run
         | Shor's algorithm at a useful scale, you need a few thousand
         | very high quality logical qubits.
         | 
         | So despite this significant progress, it's probably a still a
         | while until RSA is put out of the job. That being said, quantum
         | computers would be able to retroactively break any public keys
         | that were stored, so there's a case to be made for switching to
         | quantum-resistant cryptography (like lattice-based
         | cryptography) sooner rather than later.
        
           | rhubarbtree wrote:
           | This is correct. I worked in quantum research a little.
        
             | orliesaurus wrote:
             | any books for beginners that you recommend?
        
               | macrolime wrote:
               | https://quantum.country/qcvc
        
               | sebastialonso wrote:
               | This is an outstanding resource, thanks!
        
             | ozzsama wrote:
             | Dear rhubarbtree,
             | 
             | I'm very sorry to admit it but I'm too lazy to read the
             | entire discussion in this thread. Could you please tell me,
             | a mere mortal, at which point the humanity should start
             | worrying about the security of asymmetric encryption in the
             | brave new world of quantum computing?
        
           | rhaps0dy wrote:
           | Thank you for the explanation. It's still an upwards update
           | on the qubit timelines of https://arxiv.org/pdf/2009.05045
           | (see Fig. 7), but not by an insane amount. We've realized
           | their 95% expectation of qubit progress (1 logical qubit) for
           | 2026, in 2024.92 instead.
           | 
           | Which to be clear is quite a bit faster than expected in
           | 2020, but still within the realm of plausible stuff.
        
             | qnleigh wrote:
             | Nice, thanks for linking that paper. I also did below.
             | 
             | The authors argue (e.g. in the first comment here
             | https://scottaaronson.blog/?p=8310#comments) that by their
             | definition, Google still only has a fraction of one logical
             | qubit. Their logical error rate is of order 1e-3, whereas
             | this paper considers a logical qubit to have error of order
             | 1e-18. Google's breakthrough here is to show that the
             | logical error rate can be reduced exponentially as they
             | make the system larger, but there is still a lot of scaling
             | work to do to reach 1e-18.
             | 
             | So according to this paper, we are still on roughly the
             | same track that they laid out, and therefore might expect
             | to break RSA between 2040 and 2060. Note that there are
             | likely a lot of interesting things one can do before
             | breaking RSA, which is among the hardest quantum algorithms
             | to run.
        
           | kortilla wrote:
           | > quantum computers would be able to retroactively break any
           | public keys that were stored
           | 
           | Use a key exchange that offers perfect forward secrecy (e.g.
           | diffie Hellman) and you don't need to worry about your RSA
           | private key eventually being discovered.
        
             | HeatrayEnjoyer wrote:
             | Not exactly, they can just reverse the entire chain.
        
               | kortilla wrote:
               | What chain are you talking about?
        
             | ReptileMan wrote:
             | Perfect forward secrecy doesn't work that well when NSA
             | motto is - store everything now decrypt later. If they
             | intercept the ephemeral key exchange now they can decrypt
             | the message 10 or 50 years later.
        
               | JKCalhoun wrote:
               | Something tells me that by the end of the century only
               | the one-time pads will still be holding their secrets.
        
               | FredPret wrote:
               | Even for that to work you need a good random number
               | generator
        
               | adgjlsfhk1 wrote:
               | That's pretty trivial. xor a video camera with AES and no
               | one is decrypting that ever.
        
               | JKCalhoun wrote:
               | And, famously, the camera is pointing at a lava lamp, ha
               | ha.
        
               | JKCalhoun wrote:
               | Honestly not sure how they created one-time pads 100
               | years ago.
        
               | rdtsc wrote:
               | In one case it was people just banging on typewriters
               | randomly.
        
               | kortilla wrote:
               | Diffie Hellman doesn't ever send the key over the wire,
               | that's the point. There is nothing to decrypt in the
               | packets that tells you the key both sides derived.
               | 
               | Unless they break ECDHE, it doesn't matter if RSA gets
               | popped.
        
               | bsaul wrote:
               | wouldn't be surprised if ecdhe isn't quantum resistant.
        
               | ReptileMan wrote:
               | Diffie Hellman to the best of my understanding also
               | relies on the same hard problems that make the public key
               | cryptography possible. If you trivialize factoring of big
               | numbers, you break both RSA and the original DHE. Not
               | sure how it will work for elliptic curves, but my
               | instinct tells me that if you make the fundamental ECC
               | problem easy, the exchange will also go down.
        
               | Thorrez wrote:
               | According to the top image on the Wikipedia page, Diffie
               | Hellman does send the public key over the wire.
               | 
               | https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_
               | exc...
        
             | dathery wrote:
             | Diffie-Hellman isn't considered to be post-quantum safe: ht
             | tps://en.wikipedia.org/wiki/Shor%27s_algorithm#Feasibility.
             | ..
        
             | lxgr wrote:
             | Forward secrecy is orthogonal to post-quantum safety.
        
             | ramchip wrote:
             | > Forward secrecy is designed to prevent the compromise of
             | a long-term secret key from affecting the confidentiality
             | of past conversations. However, forward secrecy cannot
             | defend against a successful cryptanalysis of the underlying
             | ciphers being used, since a cryptanalysis consists of
             | finding a way to decrypt an encrypted message without the
             | key, and forward secrecy only protects keys, not the
             | ciphers themselves.[8] A patient attacker can capture a
             | conversation whose confidentiality is protected through the
             | use of public-key cryptography and wait until the
             | underlying cipher is broken (e.g. large quantum computers
             | could be created which allow the discrete logarithm problem
             | to be computed quickly). This would allow the recovery of
             | old plaintexts even in a system employing forward secrecy.
             | 
             | https://en.wikipedia.org/wiki/Forward_secrecy#Attacks
        
               | kortilla wrote:
               | I'm talking specifically about RSA being eventually
               | broken. If just RSA is broken and you were using ECDHE
               | for symmetric keying, then you're fine.
               | 
               | The point is that you can build stuff on top of RSA today
               | even if you expect it to be broken eventually if RSA is
               | only for identity verification.
        
               | minitech wrote:
               | The relevant RSA break is sufficiently powerful quantum
               | computers, which also break ECDH (actually, ECDH is
               | easier than classically equivalent-strength RSA for
               | quantum computers[1]), so no, you're not fine.
               | 
               | [1]
               | https://security.stackexchange.com/questions/33069/why-
               | is-ec...
        
               | coppsilgold wrote:
               | I would actually expect RSA to see a resurgence due to
               | this. Especially because you can technically scale RSA to
               | very high levels potentially pushing the crack date to
               | decades later than any ECC construction. With the
               | potential that such a large quantum computer may never
               | even arrive.
               | 
               | There are several choices with scaling RSA too, you can
               | push the primes which slows generation time considerably.
               | Or the more reasonable approach is to settle on a prime
               | size but use multiple of them (MP-RSA). The second
               | approach scales indefinitely. Though it would only serve
               | a purpose if you are determined to hedge against the
               | accepted PQC algorithms (Kyber/MLKEM, McEliece) being
               | broken at some point.
        
               | bwesterb wrote:
               | If you don't mind a one terabyte public key.
               | https://eprint.iacr.org/2017/351.pdf
        
               | adgjlsfhk1 wrote:
               | also that paper (IMO) is ridiculously conservative. Just
               | using 1GB keys is plenty sufficient since it would
               | require a quantum computer with a billion bits to
               | decrypt.
        
               | trogdor wrote:
               | Although I know it's an apocryphal quote, I am reminded
               | of "640K should be enough for anybody."
               | 
               | The Intel 4004, in 1971, had only 2,250 transistors.
               | 
               | A handful of qubits today might become a billion sooner
               | than you think.
        
               | Vecr wrote:
               | How long does it take to generate a key that big? What
               | probabilities do you need to put on generating a
               | composite number and not a prime? Does the prime need
               | extra properties?
        
             | coppsilgold wrote:
             | Perfect forward secrecy requires the exchange of ephemeral
             | keys. If you use either ECC or RSA for this and the traffic
             | is captured a quantum computer will break it.
             | 
             | All perfect forward secrecy means is that you delete your
             | own ephemeral private keys, the public keys stay in the
             | record. And a quantum computer will recover the deleted
             | private keys.
             | 
             | Also, none of the currently accepted post-quantum
             | cryptographic algorithms offer a Diffie-Hellman
             | construction. They use KEM (Key Encapsulation Mechanism).
        
           | prmoustache wrote:
           | > so there's a case to be made for switching to quantum-
           | resistant cryptography (like lattice-based cryptography)
           | sooner rather than later.
           | 
           | This.
           | 
           | People seems to think that because something is end to end
           | encrypted it is secure. They don't seem to grasp that the
           | traffic and communication that is possibly dumped/recorded
           | now in encrypted form could be used against them decades
           | later.
        
             | pas wrote:
             | Well. Yes, but currently there are no well tested (ie.
             | recommended by the ITsec community) post-quantum
             | cryptosystems as far as I understand.
             | 
             | https://crypto.stackexchange.com/a/61596
             | 
             | But ... AES is believed to be quantum-safe-ish, so with
             | perfect forwards secrecy this exact threat can be quite
             | well managed.
             | 
             | The currently best known quantum attack on AES requires a
             | serial computation of "half of key length" (Grover's
             | algorithm ... so if they key is 128 bit long then it
             | requires 2^64 sequential steps)
             | 
             | https://www.reddit.com/r/AskNetsec/comments/15i0nzp/aes256_
             | i...
        
               | _tk_ wrote:
               | Google uses NTRU-HRSS internally, which seems reasonable.
               | 
               | https://cloud.google.com/blog/products/identity-
               | security/why...
        
               | makeworld wrote:
               | Signal and Apple both use post-quantum.
        
               | pas wrote:
               | I read about Signal's double-trouble tactics, but I
               | haven't heard about Apple's.
               | 
               | Ah, okay for iMessage, something called PQ3[1], hm, it
               | uses Kyber. And it's also a hybrid scheme, combining ECC.
               | And a lot of peer review.
               | 
               | And there's also some formal verification for Signal's
               | PQXDH [2].
               | 
               | Oh, wow, not bad. Thanks!
               | 
               | Now let's hope a good reliable sane implementation
               | emerges so others can also try this scheme. (And I'm very
               | curious of the added complexity/maintenance burden and
               | computational costs. Though I guess this mostly runs on
               | the end users' devices, right?)
               | 
               | [1] https://security.apple.com/blog/imessage-pq3/ [2]
               | https://github.com/Inria-Prosecco/pqxdh-analysis
        
         | r33b33 wrote:
         | > Worth spending a little time doing some long tail
         | strategizing I'd say.
         | 
         | What do you mean by this?
        
           | unethical_ban wrote:
           | The _only_ thing I know or understand about quantum computing
           | is its ability to  "crack" traditional encryption algorithms.
           | 
           | So the commenter is saying that Cybersecurity needs to be
           | planning for a near-world where traditional cryptography,
           | including lots of existing data at rest, is suddenly as
           | insecure as plaintext.
        
           | tsimionescu wrote:
           | "long tail" typically refers to the tail of a normal
           | distribution - basically it's a sciencey, but common, way of
           | saying "very unlikely event". So, the OP was saying that it's
           | worth spending some time strategizing about the unlikely
           | event that a practical RSA-breaking QC appears in the near
           | future, even though it's still a "long tail" (very unlikely)
           | event.
           | 
           | Honestly, there's not that much to discuss on this though.
           | The only things you can do from this strategizing is to
           | consider even encrypted data as not safe to store, unless
           | you're using quantum resistant encryption such as AES; and to
           | budget time for switching to PQC as it becomes available.
        
         | sizzle wrote:
         | How long until this can derive a private key from its public
         | key in the cryptocurrency space? Is this an existential threat
         | to crypto?
        
           | bawolff wrote:
           | Long enough you don't need to panic or worry.
           | 
           | Short enough that its reasonable to start r&d efforts on post
           | quantum crypto.
        
             | sizzle wrote:
             | Is there a way to fork and add a quantum-proof encryption
             | layer on the existing cryptocurrency paradigm i.e. Bitcoin
             | 2.0?
        
               | bawolff wrote:
               | You could replace ECDSA with a post quantum algorithm.
               | Keep in mind that many crypto primitives are safe, so
               | there are large parts of bitcoin where you don't have to
               | do anything. Digital signatures is going to be where the
               | main problem is for bitcoin. But thinks like the hash
               | algorithm should be fine (at most quantum gives a square
               | root speed up for hashing, which isn't enough to be
               | really concerning).
               | 
               | One thing that might be problematic for a blockchain
               | where everything has to go on the blockchain forever is
               | that some post quantum schemes have really large
               | signatures or key sizes.
               | 
               | I'm not that familiar with the details of bitcoin, but i
               | had the impression that p2pkh is more secure against
               | quantum computers.
               | 
               | [I should emphasize, im not a cryptographer and only
               | somewhat familiar with bitcoin]
        
         | beams_of_light wrote:
         | https://en.wikipedia.org/wiki/BGP_hijacking#Public_incidents
         | 
         | A long-term tactic of our adversaries is to capture network
         | traffic for later decryption. The secrets in the mass of
         | packets China assumedly has in storage, waiting for quantum
         | tech, is a treasure trove that could lead to crucial state,
         | corporate, and financial secrets being used against us or made
         | public.
         | 
         | AI being able to leverage quantum processing power is a threat
         | we can't even fathom right now.
         | 
         | Our world is going to change.
        
         | inasio wrote:
         | They showed a logical qubit that can last entangled for an
         | hour, but to do that they had to combine their hundred or so
         | physical qubits into a single one, so in some sense they have,
         | right now, a single (logical) qubit
        
         | weatherlite wrote:
         | > AI and data security will be unalterably different if so
         | 
         | So what are the implications if so ?
        
       | vhiremath4 wrote:
       | I really wish the release videos made things a ~tad~ bit less
       | technical. I know quantum computers are still very early so the
       | target audience is technical for this kind of release, but I
       | can't help wonder how many more people would be excited and
       | pulled in if they made the main release video more approachable.
        
         | tcgv wrote:
         | If you have programming experience, you might find this
         | interesting: back in 2019, when Google announced achieving
         | quantum supremacy, I worked on a personal project to study the
         | basics of quantum computing and share my learnings with others
         | in my blog:
         | 
         | - https://thomasvilhena.com/2019/11/quantum-computing-for-
         | prog...
        
           | vhiremath4 wrote:
           | Excellent thank you!
        
       | rdtsc wrote:
       | The main part for me is reducing error faster as they scale. This
       | was a major road-block, known as "below threshold". That's a
       | major achievement.
       | 
       | I am not sure about RCS as the benchmark as not sure how useful
       | that is in practice. It just produced really nice numbers. If I
       | had a few billions of pocket change around, would I buy this to
       | run RCS really fast? -Nah, probably not. I'll get more excited
       | when they factor numbers at a rate that would break public key
       | crypto. For that would spend my pocket change!
        
         | vessenes wrote:
         | The implication seems to be that they can implement other
         | gates. As my gen z kids say: huge if true.
        
           | wasabi991011 wrote:
           | It's really important to note that the error correction test
           | and the random circuit test are separate tests.
           | 
           | The error correction is producing a single logical qubit of
           | quantum memory, i.e. a single qubit with no gates applied to
           | it.
           | 
           | Meanwhile, the random circuit sampling uses physical qubits
           | with no error correction, and is used as a good benchmark in
           | part because it can prove "quantumness" even in the presence
           | of noise.[1]
           | 
           | [1] https://research.google/blog/validating-random-circuit-
           | sampl...
        
       | fidotron wrote:
       | The slightly mind blowing bit is detailed here: >
       | https://research.google/blog/making-quantum-error-correction...
       | 
       | "the first quantum processor where error-corrected qubits get
       | exponentially better as they get bigger"
       | 
       | Achieving this turns the normal problem of scaling quantum
       | computation upside down.
        
         | thrance wrote:
         | It also breaks a fundamental law of quantum theory, that the
         | bigger a system in a quantum state is, the faster it collapses,
         | exponentially so. Which should at least tell you to take
         | Google's announcement with z grain of salt.
        
           | wasabi991011 wrote:
           | This is not a "fundamental law of quantum theory", as
           | evidenced by the field of quantum error correcting codes.
           | 
           | Google's announcement is legit, and is in line with what
           | theory and simulations expect.
        
         | bgnn wrote:
         | Hmm why? I thought the whole idea was this would work
         | eventually. Physical qubit vs logical qubit distinction is
         | there already for a long time.
         | 
         | The scaling problem is multifaceted. IMHO the physical qubits
         | are the biggest barrier to scaling.
        
           | fidotron wrote:
           | > Hmm why?
           | 
           | In theory, theory and practice are the same.
        
       | whimsicalism wrote:
       | We need to seriously think if our systems/society are even
       | remotely ready for this.
        
         | germandiago wrote:
         | In order to evolve, forbiding evolution is the wrong path. Just
         | use and study and learn from new things and accumulate
         | experience is the way to go.
        
           | kridsdale1 wrote:
           | Biological evolution occurs on the backs of millions of
           | deaths.
        
             | hello_computer wrote:
             | and a few extinctions!
        
         | _benj wrote:
         | This comment reminded me of the TV show I've been recently
         | watching on Netflix, Pantheon. It's about a different technical
         | breakthrough (I don't want to put any spoilers), but it's also
         | something that completely alters society, no security is able
         | to deal with that new technology, first thing that happens is
         | that the technology is weaponized... etc.
         | 
         | Idk enough about quantum computing to even understand this...
         | but a technology that turns, say, AES or Blowfish, suddenly
         | trivial to crack would very likely change the world
        
           | kridsdale1 wrote:
           | This is how I feel about drones.
        
             | riiii wrote:
             | They'll be banned for public use in the next 2-3 years. I'm
             | not advocating for the ban, just saying it'll happen.
        
               | debacle wrote:
               | It's easier to make a "ghost drone" than a "ghost gun."
               | Banning will not be feasible for bad actors.
        
               | mrguyorama wrote:
               | Banning anything is never about stopping theoretical "bad
               | actors", it's about reducing the number of normal people
               | who pick up "bad thing" and making mere ownership a
               | suspicious enough act to compel investigation. It's about
               | making things harder. A gun on a black market will be
               | more expensive in a place that makes guns in general
               | illegal. Small time Timmy will not be able to afford a
               | gun to back up his desire to rob the local liquor store.
               | 
               | Systemic design is usually about how you affect the
               | margins
        
         | seanw444 wrote:
         | They're not. What's there to think about?
        
         | preisschild wrote:
         | As if "thinking about it" will ever stop people from acting
         | first.
         | 
         | I'm far more scared when tech-bros like Musk land on Mars and
         | contaminate stuff we might not even be able to detect yet.
        
           | whimsicalism wrote:
           | i'm not even remotely 'far more scared' about that. i think
           | you are insufficiently scared about crypto being broken
        
             | drivebycomment wrote:
             | Quantum computer becoming available / powerful does not
             | mean all cryptography will get broken. People who have
             | actual knowledge and expertise are already busy working on
             | various aspects of PQC.
        
       | taf2 wrote:
       | Is this using ionq or is this in-house from google?
        
         | vessenes wrote:
         | They say in-house with their own US fab in the announcement.
        
       | DebtDeflation wrote:
       | >the more qubits we use in Willow, the more we reduce errors, and
       | the more quantum the system becomes
       | 
       | That's an EXTRAORDINARY claim and one that contradicts the
       | experience of pretty much all other research and development in
       | quantum error correction over the course of the history of
       | quantum computing.
        
         | wasabi991011 wrote:
         | It's really not so extraordinary, exponential reduction in
         | logical errors when the physical error rate is below a
         | threshold (for certain types of error correcting codes_ is well
         | accepted an both theoretical and computational grounds.
         | 
         | For a rough but well-sourced overview, see Wikipedia:
         | https://en.wikipedia.org/wiki/Threshold_theorem
         | 
         | For a review paper on surface codes, see A. G. Fowler, M.
         | Mariantoni, J. M. Martinis, and A. N. Cleland, "Surface codes:
         | Towards practical large-scale quantum computation," Phys. Rev.
         | A, vol. 86, no. 3, p. 032324, Sep. 2012, doi:
         | 10.1103/PhysRevA.86.032324.
        
           | DebtDeflation wrote:
           | Does this not assume uncorrelated errors?
        
             | wasabi991011 wrote:
             | It does. It's up to engineering to make errors
             | uncorrelated. The google paper being referenced actually
             | makes an "error budget" to see what the main sources of
             | errors are, and also run tests to find sources of
             | correlated errors.
             | 
             | The claim about this is that correlated errors will lead to
             | an "error floor", a certain size of error correction past
             | which exponential reduction in errors no longer applies,
             | due to a certain frequency of correlated errors. See figure
             | 3a of the arxiv version of the paper:
             | https://arxiv.org/abs/2408.13687
        
         | qnleigh wrote:
         | I wouldn't call it extraordinary, as this has been expected
         | since the first quantum error correcting codes were worked out
         | theoretically. But it is a strong claim, backed up with
         | comparably strong evidence. Figure 1d of the paper shows
         | exactly this https://arxiv.org/html/2408.13687v1, and unlike
         | many other comparable works, there are no hat tricks like post-
         | selection to boost the numbers.
        
         | deepburner wrote:
         | it... doesn't? threshold theorems are well known.
        
         | da-bacon wrote:
         | >That's an EXTRAORDINARY claim and one that contradicts the
         | experience of pretty much all other research and development in
         | quantum error correction over the course of the history of
         | quantum computing.
         | 
         | Not sure why you would say that? This sort of exponential
         | suppression of errors is exactly how quantum error correction
         | works and why we think quantum computing is viable. Source:
         | have worked on quantum error correction for a couple of
         | decades. Disclosure: I work on the team that did this
         | experiment. More reading: lecture notes from back in the day
         | explaining this exponential suppression
         | https://courses.cs.washington.edu/courses/cse599d/06wi/lectu...
        
         | pjs_ wrote:
         | It's a categorically new experimental regime but it's exactly
         | what was supposed to happen. I think it's an awesome result.
        
       | deanCommie wrote:
       | I don't want to judge people by their cover, but I want to
       | confess to having those feelings right now.
       | 
       | In this day and age, I feel an immediate sense of distrust to any
       | technologist with the "Burning Man" aesthetic for lack of a
       | better word. (which you can see in the author's wikipedia profile
       | from an adjacent festival ->
       | https://en.wikipedia.org/wiki/Hartmut_Neven, as well as in this
       | blog itself with his wristbands and sunglasses ->
       | https://youtu.be/l_KrC1mzd0g?si=HQdB3NSsLBPTSv-B&t=39)
       | 
       | In the 2000's, any embracement of alternative culture was a
       | breath of fresh air for technologists - it showed they cared
       | about the human element of society as much as the mathematics.
       | 
       | But nowadays, especially in a post-truthiness, post-COVID world,
       | it comes off in a different way to me. Our world is now filled
       | with quasi-scientific cults. From flat earthers to anti-vaxxers,
       | to people focused on "healing crystals", to the resurgence of
       | astrology.
       | 
       | I wouldn't be saying this about anyone in a more shall we say
       | "classical" domain. As a technologist, your claims are pretty
       | easily verifiable and testable, even on fuzzy areas like large
       | language models.
       | 
       | But in the Quantum world? I immediately start to approach the
       | author of this with distrust:
       | 
       | * He's writing about multiverses
       | 
       | * He's claiming a quantum performance for something that would
       | take a classical computer septillions of years.
       | 
       | I'm a layman in this domain. If these were true, should they be
       | front page news on CNN and the BBC? Or is this just how
       | technology breakthroughs start (after all the Transformer paper
       | wasn't)
       | 
       | But no matter what I just can't help but feel like the author's
       | choices harm the credibility of the work. Before you downvote me,
       | consider replying instead. I'm not defending feeling this way.
       | I'm just explaining what I feel and why.
        
         | bubblyworld wrote:
         | I don't share your mistrust of the aesthetic, but I think it's
         | pretty natural to be skeptical of the out-group, so to speak,
         | doubly so if you have no practical way of verifying their
         | claims. At least you're honest about it!
         | 
         | I guess something to think about it that amongst a group like
         | the "burners" there is huge variety in individual experience
         | and skill. And even within a single human mind it's possible to
         | have radically groundbreaking thoughts in one domain, and
         | simultaneously be a total crack-pot in another. Linus Pauling
         | and the vitamin C thing comes to mind. There's no such thing as
         | an average person!
         | 
         | I guess we'll see what the quantum experts have to say about
         | this in the weeks to come =)
        
         | leptons wrote:
         | I know Hartmut Neven personally and professionally, and have
         | for decades. He's not anything like you claim he is. Attacking
         | him for wearing a wristband? That's an ad hominem attack, and
         | not worthy of my time to counter you on.
         | 
         | The fact is that "Burners" are everywhere, nothing about
         | Burning Man means someone is automatically a quack. Your
         | distrust seems misplaced and colored by your own personal
         | biases. The list of prominent people in tech that are also
         | "burners" would likely shock you. I doubt you've ever been to
         | Burning Man, but you're going to judge people who have? Maybe
         | you're just feeling a little bit too "square" and are
         | threatened by people who live differently than you do.
         | 
         | Yes, Hartmut has a style, yes, he enjoys his lifestyle, no,
         | he's not a quack. You don't have to believe me, and I don't
         | expect that you will, but I've talked at length with him about
         | his work, and about a great many other topics, and he is not as
         | you think he is.
         | 
         | Your comment here says far more about you than it says about
         | Hartmut Neven.
        
           | deanCommie wrote:
           | > Attacking him for wearing a wristband? That's an ad hominem
           | attack, and not worthy of my time to counter you on.
           | 
           | I picked my words very carefully and I would appreciate if
           | you responded to what I said, not what you think I implied.
           | 
           | I specifically called out - I'm having feelings of bias. That
           | in a field full of quack science and overpromises and
           | underdelivery, I am extraordinarily suspicious of anyone who
           | I feel might be associated with a shall we say "less than
           | rigorous relationship with scientific accuracy". This
           | person's aesthetic reminds me of this.
           | 
           | > The fact is that "Burners" are everywhere, nothing about
           | Burning Man means someone is automatically a quack. Your
           | distrust seems misplaced and colored by your own personal
           | biases. The list of prominent people in tech that are also
           | "burners" would likely shock you. I doubt you've ever been to
           | Burning Man, but you're going to judge people who have? Maybe
           | you're just feeling a little bit too "square" and are
           | threatened by people who live differently than you do.
           | 
           | You couldn't be more wrong. I'm a repeat Burner throughout
           | the 2000's (though it's been a decade), and I've been to a
           | dozen regional Burner events. I know many Burners both in the
           | tech industry and outside of it.
           | 
           | So I actually speak with some experience. I know wonderful
           | people who are purely artists and are not
           | scientifically/technologically inclined - and they're great.
           | I also know deep technologists for whom Burning man is purely
           | an aesthetic preference - a costume not an outfit. Something
           | to pretend to be for a little while but that otherwise has no
           | bearing on their outside life.
           | 
           | And I unfortunately know those whose brainrot ends up
           | intertwining. Crypto evangelists who find healing crystals
           | just as groundbreaking as the blockchain. It's this latter
           | category that I am the most suspicious of, and what I worry
           | when I see a person presented as an authoritative leader in
           | the Quantum Computing domain demonstrate in their external
           | presentation.
           | 
           | I led with an acknowledgement that I am judging a book by
           | it's cover, which one ought to never do. But I think it is
           | worth pointing out because respectability in a cutting edge
           | field is important, lest you end up achieving technological
           | breakthroughs that don't actually change society at all (as
           | already happened with Google Glass).
           | 
           | > You don't have to believe me, and I don't expect that you
           | will,
           | 
           | Why would you expect that I wouldn't?
           | 
           | > but I've talked at length with him about his work, and
           | about a great many other topics, and he is not as you think
           | he is.
           | 
           | That's fantastic to hear! You have direct evidence
           | contradicting the assumptions generated by my first
           | impression. This is all that matters, and all you had to say.
        
             | leptons wrote:
             | >who I feel
             | 
             | You're basing things on your feelings, not personally
             | knowing the person. I know you've alluded to that, but
             | seriously, just stop.
             | 
             | > I worry when I see a person presented as an authoritative
             | leader in the Quantum Computing domain demonstrate in their
             | external presentation.
             | 
             | I'm not sure why how someone dresses makes you worry,
             | especially since you aren't even involved in QC. Stop
             | worrying about things you can't control, especially someone
             | else's appearance. _Has Burning Man taught you nothing_? If
             | you think it taught you to be biased towards someone based
             | on their appearance, then I think you completely missed the
             | point.
             | 
             | >as already happened with Google Glass
             | 
             | You may not know this, but he was tapped to lead the Google
             | Glass project, and quickly got out of it. He felt that the
             | silicon at the time was not capable of producing the
             | results people wanted in the form-factor they were
             | expecting. He was right. Of course tech has improved since
             | then and better VR/AR glasses in a convenient form factor
             | are just now starting to be a thing, but Google Glass is
             | long since shuttered.
             | 
             | He didn't just come out of nowhere, he's been involved in
             | actual AI (not LLMs) for decades. His company was bought by
             | Google and is the basis for their computer vision systems,
             | which is how he ended up at Google.
             | 
             | As for you supposing he's into "healing crystals" or any
             | other wooo nonsense simply based on how he dresses, I have
             | never known him to talk about such things at all, in all
             | our conversations throughout the decades.
             | 
             | > This person's aesthetic reminds me of this.
             | 
             | You are barking up the wrong tree, and you should maybe
             | tone down your judginess of others. I have news for you -
             | _you can 't tell a book by its cover_, but you sure are
             | trying to. You just come off as being jealous that someone
             | can have fun and also be a pioneer in QC. No doubt any
             | person at the top of their field has plenty of haters,
             | based on nothing more than "he doesn't dress like I expect
             | him to".
        
           | wasabi991011 wrote:
           | > I know Hartmut Neven personally and professionally, and
           | have for decades
           | 
           | I don't want to put you on the spot too much, but can you
           | speak to why he included the part about many-worlds in this
           | blog post?
           | 
           | I don't know enough about Google to say if maybe someone else
           | less technical wrote that, or if he is being pressured to put
           | sci-fi sounding terms in his posts, or if he believes
           | Google's quantum computer is actually testing many-worlds, or
           | some other reason I can't think of.
        
         | wasabi991011 wrote:
         | > I immediately start to approach the author of this with
         | distrust:
         | 
         | > * He's writing about multiverses
         | 
         | > * He's claiming a quantum performance for something that
         | would take a classical computer septillions of years.
         | 
         | > I'm a layman in this domain
         | 
         | I think your skepticism is well-founded. But as you learn more
         | about the field, you learn what parts are marketing/hype
         | bullshit, and what parts are not, and how to translate from the
         | bullshit to the underlying facts.
         | 
         | IMO:
         | 
         | > He's writing about multiverses
         | 
         | The author's pet theory, no relevance to the actual science
         | being done.
         | 
         | * He's claiming a quantum performance for something that would
         | take a classical computer septillions of years.
         | 
         | The classical computer is running a very naive algorithm,
         | basically brute-force. It is very easy to write a classical
         | algorithm which is very slow. But still, in the field, it takes
         | new state-of-the-art classical algorithms run on medium size
         | clusters to get results that are on-par with recent quantum
         | computers. Not even much better, just on-par.
         | 
         | > Or is this just how technology breakthroughs start (after all
         | the Transformer paper wasn't)
         | 
         | You could say that. It's not truly a breakthrough, but it is
         | one more medium-size step in a rapidly advancing field.
        
         | hello_computer wrote:
         | The hall of great scientists is packed with holders of strange
         | beliefs. Half of Newton's writings were on religious
         | speculation, alchemy, and the occult. One of Einstein's very
         | favorite books was Blavatsky's " _Isis Unveiled_ ". Just about
         | every key person in early QM was deep into the Vedas. Kary
         | Mullis was an AIDS denialist, and questioned the utility of his
         | own test as a virus detector. If you really think about it, you
         | will see that this phenomenon arises more from necessity than
         | coincidence.
        
         | Aeium wrote:
         | The quantum performance thing is real, but that the random
         | circuit sampling problem they are tabling as the benchmark here
         | is for a quantum circuit.
         | 
         | So really what is being claimed is that classical computers
         | can't easily simulate quantum ones. But is that really
         | surprising?
         | 
         | What would be surprising would be that kind of speedup vs
         | classical on some kind of general optimization algorithm. I
         | don't think that is what they are claiming though, even if it
         | does kind of seem like it's being presented that way.
        
       | pandemic_region wrote:
       | > Willow performed a standard benchmark computation in under five
       | minutes that would take one of today's fastest supercomputers 10
       | septillion years -- a number that vastly exceeds the age of the
       | Universe.
       | 
       | What computation would that be?
       | 
       | Also, what is the relationship, if any, between quantum computing
       | and AI? Are these technologies complementary?
        
         | ra7 wrote:
         | It's in the article. Random circuit sampling benchmark:
         | https://research.google/blog/validating-random-circuit-sampl...
        
           | crote wrote:
           | Is it really fair to call that "computation"? I am
           | _definitely_ not an expert, but it seems they are just doing
           | a meaningless operation which happens to be trivial on a
           | quantum computer but near-impossible to simulate on a
           | classical computer.
           | 
           | To me that sounds a bit like saying my "sand computer"
           | (hourglass) is way faster than a classical computer, because
           | it'd take a classical computer trillions of years to
           | _exactly_ simulate the final position of every individual
           | grain of sand.
           | 
           | Sure, it proves that your quantum computer is actually a
           | _genuine_ quantum computer, but it 's not going to be topping
           | the LINPACK charts or factoring large semiprimes any time
           | soon, is it?
        
             | becquerel wrote:
             | As they say explicitly in the article, this is like
             | criticizing the first rocket to reach the edge of space for
             | not getting anywhere useful.
        
               | crote wrote:
               | It seems like they went from lighting a candle to firing
               | off some fireworks. Impressive, but there's still a long
               | way to go until they can land a human on the moon - let
               | alone travel to Alpha Centauri like some people are
               | claiming.
        
             | andrewla wrote:
             | Yes, this is exactly what it is doing [1]. The area of
             | research is Noisy Intermediate Scale Quantum, and has
             | arisen specifically to prove that quantum supremacy is
             | possible in practice. It is currently the focus of pretty
             | much all quantum computing research because attempts to
             | produce a generalized quantum computer have all failed
             | miserably. Existing practical quantum computers (like
             | DWave) perform various annealing tasks but have basically
             | proven to be inferior to probablistic algorithms computing
             | the same task.
             | 
             | To date all attempt to produce valid claims of quantum
             | supremacy via this channel have failed on closer
             | inspection, and there is no reason to assume otherwise in
             | this case until researchers have had time to look at the
             | paper. There's a number of skeptics in the quantum
             | computing field that believe that this is simply not
             | possible.
             | 
             | [1] https://news.ycombinator.com/item?id=42369463
        
               | hermitcrab wrote:
               | Are DWave still in the running? They used my
               | PerfectTablePlan table seating software back in 2007 as
               | the front end to demonstrate solving a combinatorial
               | seating problem: https://www.perfecttableplan.com/newslet
               | ters/newsletter10_we...
        
             | drkevorkian wrote:
             | It's different from your hourglass in that the computer is
             | controllable. Each sampled random circuit requires choosing
             | all of the operations that the computer will perform. You
             | have no control over what operation the hourglass does.
             | 
             | It won't be factoring large numbers yet because that
             | computation requires the ability to perform millions of
             | operations on thousands of qubits without any errors. You
             | need very good error correction to do that, but luckily
             | that's the other thing they demonstrated. Only when they do
             | error correction, they are basically combining their system
             | down into one effective qubit. They'll need to scale by
             | several orders of magnitude to have hundreds of error
             | corrected qubits to do factoring.
        
         | 0xB31B1B wrote:
         | "Also, what is the relationship, if any, between quantum
         | computing and AI? Are these technologies complementary?"
         | 
         | AI is limited in part by the computation available at training
         | and runtime. If your computer is 10^X times faster, then your
         | model is also "better". Thats why we have giant warehouses full
         | of H100 chips pulling down a few megawatts from the grid right
         | now. Quantum computing could theoretically allow your phone to
         | do that.
        
           | spencerflem wrote:
           | A quantum computer is not just a 10^X faster normal computer.
           | 
           | Are there AI algorithms that would benefit from quantum?
        
           | kridsdale1 wrote:
           | Makes sense. My brain is able to do that work on milliwatts.
        
             | pdabbadabba wrote:
             | Actually about 20 W -- if you ignore the 80 W used by the
             | rest of the body (which seems debatable). And clearly far
             | more than this was required to 'train' the human brain to
             | the level of intelligence we have today.[1] But this still
             | probably doesn't take away from your point. The human brain
             | seems to be many orders of magnitude more efficient than
             | our most advanced AI technology.
             | 
             | Though the more I think about this, the more I wonder how
             | they really would compare if you made a strictly apples-to-
             | apples comparison.
             | 
             | [1]
             | https://psychology.stackexchange.com/questions/12385/how-
             | muc...
        
         | wasabi991011 wrote:
         | > Also, what is the relationship, if any, between quantum
         | computing and AI? Are these technologies complementary?
         | 
         | Ongoing research.
         | 
         | The main idea of quantum machine learning is that qubits make
         | an exponentially high-dimensional space with linear resources,
         | so can store and compute a lot of data easily.
         | 
         | However, getting the data in and results out of the quantum
         | computer is tricky, and if you need many iterations in your
         | optimization, that may destroy any advantage you have from
         | using quantum computers.
        
         | oldgradstudent wrote:
         | > Also, what is the relationship, if any, between quantum
         | computing and AI? Are these technologies complementary?
         | 
         | AI is quite good in producing the meaningless drivel needed for
         | quantum computing related press releases.
        
       | sys32768 wrote:
       | In other words, get off the cloud so nobody has your encrypted
       | data which they will be able to crack in a few minutes five or
       | ten years from now?
        
         | noident wrote:
         | It depends on the algorithm you use to encrypt your data.
         | 
         | Only asymmetric cryptography is threatened. There is no
         | realistic threat to symmetric encryption like AES.
         | 
         | If you are encrypting your cloud data with ed25519 or RSA, then
         | yes, a quantum computer could theoretically someday crack them.
        
           | Havoc wrote:
           | > Only asymmetric cryptography is threatened.
           | 
           | aka everything we use daily
        
       | codeulike wrote:
       | They opened the API for it and I'm sending requests but the
       | response always comes back 300ms before I send the request, is
       | there a way of handling that with try{} predestined{} blocks? Or
       | do I need to use the Bootstrap Paradox library?
        
         | timcobb wrote:
         | What does Gemini say?
        
           | KTibow wrote:
           | It responds with 4500 characters:
           | https://hst.sh/olahososos.md
        
         | wk_end wrote:
         | Finally, INTERCAL's COME FROM statement has a practical use.
        
         | handfuloflight wrote:
         | Have you tried using the Schrodinger Exception Handler? It
         | catches errors both before and after they occur simultaneously,
         | until you observe the stack trace.
        
           | oblio wrote:
           | I swear I can't tell which of these comments are
           | sarcastic/parody and which are actual answers.
           | 
           | A sort of quantum commenting conundrum, I guess.
        
             | camillomiller wrote:
             | They are both, just until the moment you try to read them
        
               | weakwire wrote:
               | I read them as sarcastic. Please reply here with your
               | output.
        
               | AnimalMuppet wrote:
               | Since you read them as sarcastic, I also read them as
               | sarcastic. Quantum entanglement at work.
        
               | 3l3ktr4 wrote:
               | This subthread are among the best comments I've read in
               | this website.
        
         | nobrains wrote:
         | What happens when you don't send the request after receiving
         | the response? Please try and report back.
        
           | r3trohack3r wrote:
           | You unlock the "You've met a terrible fate." achievement [1]
           | 
           | [1] https://outerwilds.fandom.com/wiki/Achievements
        
             | atoav wrote:
             | I love myself a good Zelda reference
        
           | ukuina wrote:
           | Please report back and try.*
        
           | tealpod wrote:
           | Looks like we don't have a choice.
        
           | jmcqk6 wrote:
           | No matter what we've tried so far, the request ends up being
           | sent.
           | 
           | The first time I was just watching, determined not to press
           | the button, but when I received the response, I was startled
           | into pressing it.
           | 
           | The second time, I just stepped back from my keyboard, and my
           | cat came flying out of the back room and walked on the
           | keyboard, triggering the request.
           | 
           | The third time, I was holding my cat, and a train rumbled by
           | outside, rattling my desk and apparently triggering the
           | switch to send the request.
           | 
           | The fourth time, I checked the tracks, was holding my cat,
           | and stepped back from my keyboard. Next thing I heard was a
           | POP from my ceiling, and the request was triggered. There was
           | a small hole burned through my keyboard when I examined it.
           | Best I can figure, what was left of a meteorite managed to
           | hit at exactly the right time.
           | 
           | I'm not going to try for a fifth time.
        
         | cloudking wrote:
         | The answer is yes and no, simultaneously
        
         | yu3zhou4 wrote:
         | Did you try staring on your IP packets while sending the
         | requests?
        
         | Nifty3929 wrote:
         | Try using inverse promises. You get back the result you wanted,
         | but if you don't then send the request the response is useless.
         | 
         | It's a bit like Jeopardy, really.
        
         | dtquad wrote:
         | >They opened the API for it and I'm sending requests but the
         | response always comes back 300ms before I send the request
         | 
         | For a brief moment I thought this was some quantum-magical side
         | effect you were describing and not some API error.
        
           | pinkmuffinere wrote:
           | Isn't that.... the joke?
        
         | vangamoZX wrote:
         | Write the catch clause before the try block
        
         | sebastiennight wrote:
         | You are getting that response 300ms beforehand because your
         | request is denied.
         | 
         | If you auth with the bearer token "And There Are No Friends At
         | Dusk." then the API will call you and tell you which request
         | you wanted to send.
        
         | GuB-42 wrote:
         | It think you are supposed to use a "past" object to get your
         | results before calling the API.
        
         | tiborsaas wrote:
         | Try setting up a beam-splitter router and report back with the
         | interference pattern. If you don't see a wave pattern it might
         | be because someone is spying on you.
        
         | yonatan8070 wrote:
         | Pretty sure you just need to use await-async (as opposed to
         | async-await)
        
         | codeulike wrote:
         | Update: I tried installing the current Boostrap Paradox library
         | but it says I have to uninstall next years version first.
        
         | nick3443 wrote:
         | Help! Every time I receive the response, an equal number of
         | bits elsewhere in memory are reported as corrupt by my ECC RAM.
        
         | robomartin wrote:
         | > I'm sending requests but the response always comes back 300ms
         | before I send the request
         | 
         | Ah. Newbie mistake. You need to turn OFF your computer and
         | disconnect from the network BEFORE sending the request. Without
         | this step you will always receive a response before the request
         | is issued.
        
         | qingcharles wrote:
         | I'm trying to write a new version of Snake game in Microsoft Q#
         | but it keeps eating its own tail.
        
       | kernal wrote:
       | >Willow's performance on this benchmark is astonishing: It
       | performed a computation in under five minutes that would take one
       | of today's fastest supercomputers 1025 or 10 septillion years. If
       | you want to write it out, it's 10,000,000,000,000,000,000,000,000
       | years. This mind-boggling number exceeds known timescales in
       | physics and vastly exceeds the age of the universe. It lends
       | credence to the notion that quantum computation occurs in many
       | parallel universes, in line with the idea that we live in a
       | multiverse, a prediction first made by David Deutsch.
       | 
       | A much simpler explanation is that your benchmark is severely
       | flawed.
        
         | wasabi991011 wrote:
         | "Severely flawed" is a matter of interpretation, and I don't
         | want to argue for or against.
         | 
         | But to put into context, these numbers are likely accurate, but
         | represent the time it would take for a very naive classical
         | algorithm (possibly brute-force, I am unsure).
         | 
         | For example, the previous result claimed it would take Summit
         | 10,000 years to do the same calculation as the Sycamore quantum
         | chip. However, other researchers were able to reproduce results
         | classically using tensor-network-based methods in 14.5 days
         | using a "relatively small cluster". [1]
         | 
         | [1] G. Kalachev, P. Panteleev, P. Zhou, and M.-H. Yung,
         | "Classical sampling of random quantum circuits with bounded
         | fidelity," arXiv.org, https://arxiv.org/abs/2112.15083
         | (accessed Dec. 9, 2024).
        
       | xnx wrote:
       | Is anyone else even close to Google in this space? (e.g. on the
       | "System Metrics" the blog defines)
        
         | wasabi991011 wrote:
         | I would expect IBM, but I can't find any information on their
         | system metrics based on a quick google search.
         | 
         | Would love if someone could weight in.
        
         | lanthissa wrote:
         | not publicly
        
         | taf2 wrote:
         | IonQ - they are powering AWS solution here:
         | https://aws.amazon.com/braket/quantum-computers/ionq/
         | 
         | Not sure if they are close in terms of specs but looks like
         | they are a viable solution and seeing an increase in
         | utilization over the last year... Seems both are pretty
         | interesting to keep an eye on.
        
         | EvgeniyZh wrote:
         | Main players IMHO are IBM and Quantinuum, the latter employing
         | different platform (ions). Neither could perform the same
         | experiment I think, but have their own advantages. QuEra also
         | looks good but are not as mature yet imho.
        
         | paxys wrote:
         | Give it a few more years and a smaller, more focused company
         | will come in and launch a successful product based on their
         | research.
        
         | cahaya wrote:
         | I'm wondering how this Google announcement will have an impact
         | on their future revenue, and how easily competitors can
         | replicate this breakthrough?
        
         | krick wrote:
         | I would be very grateful if somebody can point to an actually
         | good blogpost/video that would summarize the current state of
         | the domain. I mean, I remember some "quantum annealing"
         | providers as far as some 10 years ago (I mean, as a service, as
         | such D-Wave exists for 25 years now), but I never actually
         | learned if they are truly useful for anything (like, real
         | numbers, what amount of computation these thing can perform and
         | if it's truly cheaper/faster than throwing a bunch of GPUs on
         | it). From time to time there are some news feturing dope
         | photos, about some new chip from IBM, that is useful for
         | nothing, but a big breakthrough for reasons I don't understand.
         | 
         | But I don't really have a feel of what's going on, really. How
         | many quantum computers there are, is there anything that is
         | actually capable of performing anything more than just being an
         | ongoing research prototype? Some educated guesses about how far
         | can be some non-public projects by now? Like, is it possible
         | that some secret CIA project is further ahead than what we
         | know, or if it's even more unlikely and farther away than
         | fusion power? Or maybe it's even more comparable to cold
         | fusion?
         | 
         | I know, that this kinda exists as an idea, and apparently
         | somebody's working on it, but that's pretty much it.
        
       | fguerraz wrote:
       | Am I oversimplifying in thinking that they've demonstrated that
       | their quantum computer is better than at simulating a quantum
       | system than a classical computer?
       | 
       | In which case, should I be impressed? I mean sure, it sounds like
       | you've implemented a quantum VM.
        
         | TachyonicBytes wrote:
         | Simulating a quantum system is a hard challenge and it's
         | actually how Feynman proposed the quantum computing paradigm in
         | the first place. It's basically the original motive.
        
           | freetonik wrote:
           | Exactly.
           | 
           | I've seen lots of people dismissing this as if it isn't
           | impressive or important. I've watched one video where the
           | author said in a deprecating manner "quantum computers are
           | good for just two things: generating random numbers and
           | simulating quantum systems".
           | 
           | It's like saying "the thing is good for just two things:
           | making funny noises and producing infinite energy".
           | 
           | (Also, generating random numbers is pretty useful, but I
           | digress)
        
       | slater wrote:
       | I bet Vimeo videos will still chug on it
        
       | TachyonicBytes wrote:
       | Link to the actual article:
       | https://www.nature.com/articles/s41586-024-08449-y
        
         | qnleigh wrote:
         | and the arXiv preprint, which isn't paywalled
         | https://arxiv.org/html/2408.13687v1
        
           | wasabi991011 wrote:
           | And contains more information, figures, and lots of
           | supplementary material.
        
       | zelon88 wrote:
       | > It lends credence to the notion that quantum computation occurs
       | in many parallel universes, in line with the idea that we live in
       | a multiverse, a prediction first made by David Deutsch.
       | 
       | Can someone explain to me how he made the jump from "we achieved
       | a meaninful threshold in quantum computing performance" to "The
       | multiverse is probably real."
        
         | dekhn wrote:
         | The explanation is that Hartmut Neven has a bunch of sci-fi
         | beliefs and somehow has managed to hold onto his job and even
         | get to write parts of press releases.
        
         | not_a_bot_4sho wrote:
         | My money is on edibles.
        
       | radioactivist wrote:
       | Some of these results have been on the arxiv for a few months
       | (https://arxiv.org/abs/2408.13687) -- are there any details on
       | new stuff besides this blog post? I can't find anything on the
       | random circuit sampling in the preprint (or its early access
       | published version).
        
         | qnleigh wrote:
         | The peer-reviewed version at Nature has more technical details
         | about the processor itself.
        
       | ryandvm wrote:
       | Imagine your civilization develops quantum computing technology
       | and it's for... advertising.
       | 
       | "What is their mission? Cure cancer? Eliminate poverty? Explore
       | the universe? No, their goal: to sell another fucking Nissan."
       | --Scott Galloway
        
         | mperham wrote:
         | That's how you monetize attention, digital consumption. If you
         | aren't paying for it, you are the product being sold.
        
           | NoOn3 wrote:
           | In modern world, sometimes, even if you pay for it, it
           | doesn't always give guarantees... :(
        
       | softwaredoug wrote:
       | With this plus the weather model announcement. I'm curious what
       | people think about the meta question on why corporate labs like
       | Google DeepMind etc seem to make more progress on big problems
       | than academia?
       | 
       | There are a lot of critiques about academia. In particular that
       | it's so grant obsessed you have to stay focused on your next
       | grant all the time. This environment doesnt seem to reward
       | solving big problems but paper production to prove the last grant
       | did something. Yet ostensibly we fund fundamental public research
       | precisely for fundamental changes. The reality seems to be the
       | traditional funding model create incremental progress within
       | existing paradigms.
        
         | LeftHandPath wrote:
         | I did quantum computing research in university. We did
         | meaningful work and published meaningful research.
         | 
         | Around 50% of our time was spent working in Overleaf making
         | small improvements to old projects so that we could submit to
         | some new journal or call-for-papers. We were always doing peer
         | review or getting peer reviewed. We were working with a lot of
         | 3rd-party tools (e.g. FPGAs, IBM Q, etc). And our team was
         | constantly churning due to people getting their degrees and
         | leaving, people getting too busy with coursework, and people
         | deciding they just weren't interested anymore.
         | 
         | Compare that to the corporate labs: They have a fully
         | proprietary ecosystem. The people who developed that ecosystem
         | are often the ones doing research on/with it. They aren't
         | taking time off of their ideas to handle peer-review processes.
         | They aren't taking time off to handle unrelated coursework.
         | Their researchers don't graduate and start looking for
         | professor positions at other universities.
         | 
         | It's not surprising in the slightest that the corporate labs do
         | better. They're more focused and better suited for long-term
         | research.
        
           | softwaredoug wrote:
           | I wonder what makes research different than product
           | development at a company?
           | 
           | Because in product development, there can be short-sighted
           | industry decisions based on quarterly returns. I've also seen
           | a constant need to justify outcomes based on KPIs etc, and
           | constantly justifying your work, etc.
        
             | LeftHandPath wrote:
             | Research _is_ product development. Successful companies
             | treat it with respect.
             | 
             | > Because in product development, there can be short-
             | sighted industry decisions based on quarterly returns. I've
             | also seen a constant need to justify outcomes based on KPIs
             | etc, and constantly justifying your work, etc.
             | 
             | I have seen this as well. It's extremely common (especially
             | among publicly-owned companies) and frustrating. But it's
             | not ubiquitous. Consider LM's Skunkworks or Apple's quiet
             | development of the iPhone, and compare it to companies that
             | finish a product and then focus on cutting costs / nickel-
             | and-diming their customers.
        
         | anonymousDan wrote:
         | Where exactly do you think the idea for a quantum computer came
         | from in the first place?
        
         | lysecret wrote:
         | I can only speak for the weather models (since it is in my
         | domain). The answer is that the issues are much more
         | engineering and scaling/infra issues than theoretical issues,
         | and google is good at engineering (or attracts people that
         | are).
        
       | andrewla wrote:
       | This is yet another attempt to posit NISQ results (Noisy
       | Intermediate Scale Quantum) as demonstrations of quantum
       | supremacy. This does not allow us to do useful computational
       | work; it's just making the claim that a bathtub full of water can
       | do fluid dynamic simulations faster than a computer with a
       | bathtub-full-of-water-number-of-cores can do the same
       | computation.
       | 
       | If history is any guide we'll soon see that there are problems
       | with the fidelity (the system they use to verify that the results
       | are "correct") or problems with the difficulty of the underlying
       | problem, as happened with Google's previous attempt to
       | demonstrate quantum supremacy [1].
       | 
       | [1] https://gilkalai.wordpress.com/2024/12/09/the-case-
       | against-g... -- note that although coincidentally published the
       | same day as this announcement, this is talking about Google's
       | previous results, not Willow.
        
       | cryptozeus wrote:
       | QTUM
        
         | cloudking wrote:
         | Contains MSTR and not GOOG...
        
           | cryptozeus wrote:
           | Point is to get in before goog gets in
        
       | djoldman wrote:
       | I wonder if anyone else will be forced to wait on
       | https://scottaaronson.blog/ to tell us if this is significant.
        
         | gloriousduke wrote:
         | I was about to add a similar comment. Definitely interested to
         | read his evaluation and whether there is more hype than
         | substance here, though I'm guessing it may take some time.
        
         | EvgeniyZh wrote:
         | He told when the preprint was published
         | 
         | https://scottaaronson.blog/?p=8310
        
         | qnleigh wrote:
         | He's already blogged about it a bit here
         | 
         | https://scottaaronson.blog/?p=8310#comments
         | 
         | and here
         | 
         | https://scottaaronson.blog/?p=8329
         | 
         | though I bet he will have more to say now that the paper is
         | officially out.
        
       | bn-l wrote:
       | This is weird. I got this pop up halfway through reading:
       | 
       | > After reading this article, how has your perception of Google
       | changed? Gotten better Gotten worse Stayed the same
        
       | beyondCritics wrote:
       | >It lends credence to the notion that quantum computation occurs
       | in many parallel universes, in line with the idea that we live in
       | a multiverse, a prediction first made by David Deutsch.
       | 
       | Makes sense, or doesn't it? What's your take on the multiverse
       | theory?
        
       | dom96 wrote:
       | Can anyone comment on how this chip is built? What does the
       | hardware look like?
        
       | stan_kirdey wrote:
       | Is anyone fine-tuning llama to write Q#? I feel LLMs can be a
       | helpful tool in learning how to code quantum systems.
        
       | dtquad wrote:
       | Do Americans still want to breakup the big US tech companies like
       | Google? With proper regulation it feels like their positive
       | externalities, like this, is good for humanity.
        
         | 0_____0 wrote:
         | "Proper regulation" may involve breaking companies into pieces
         | such that they cannot dominate industries and deprive the
         | public the option of choosing a different provider for the
         | services they provide. Does an Alphabet subsidiary working on
         | quantum computer research require 90% of search traffic to go
         | through Google? Or for Android handsets to send a really
         | phenomenal amount of telemetry back to the mothership with no
         | real recourse for the average user?
        
         | skort wrote:
         | The key words here are "proper regulation". In an era where
         | industries have captured governmental bodies, there will likely
         | be no such regulation, and these tech companies will continue
         | to siphon up resources and funnel them to a handful at the top.
         | 
         | A quote from the article is especially ludicrous: > to benefit
         | society by advancing scientific discovery, developing helpful
         | applications, and tackling some of society's greatest
         | challenges
         | 
         | You don't need a quantum computer to do this. We can solve
         | housing and food scarcity today, arguably our greatest
         | challenges. Big tech has been claiming that it's going to solve
         | all of our problems for decades now and it has yet to put up.
         | 
         | If you want this type of technology to be made and do actual
         | good, we need publicly funded research institutions. Tech won't
         | save us.
        
           | noisy_boy wrote:
           | Regulation is the handle of the chainsaw aka corporation.
           | Right now it is a bit wobbly which explains the cuts on the
           | society we see around us. The faster we make the blades turn
           | due to technological advances, the firmer the handle needs to
           | be.
        
       | correlator wrote:
       | I met julian touring UCSB as perspective grad students. We sat
       | together at dinner and he was really smart, kind, and outgoing.
       | Great to see him presenting this work!
        
       | robot wrote:
       | there is so much skepticism on quantum computing that instead of
       | inflated marketing words one should always start by what the
       | biggest problems are, how they are not still solved yet, and then
       | introduce what the new improvement is.
       | 
       | Otherwise there is no knowing if the accomplishment is really
       | significant or not.
        
         | gauge_field wrote:
         | Especially if you consider how they choose the words and how
         | they can be interpreted
         | 
         | " Second, Willow performed a standard benchmark computation in
         | under five minutes that would take one of today's "
         | 
         | Standard benchmark in what sense. Well, it was chosen for task
         | where quantum computer would have better performance.
         | 
         | I am not saying this is nothing. Maybe, use more reserved
         | words, e.g. "special quantum oriented benchmark" or something.
         | 
         | When I think of standard benchmark, I am thinking more common
         | scenarios, e.g. searching, sorting, matrix multiplication.
        
       | Sakurai_Quantum wrote:
       | Great time to learn the mathematical foundations of quantum
       | computing rigorously:
       | https://quantumformalism.academy/mathematical-foundations-fo....
       | All self-paced with problem sheets (proof challenges) and worked
       | out solutions, etc.
        
         | Sakurai_Quantum wrote:
         | Here is a free preview (lecture 6): https://youtu.be/6rf-
         | hjyNl4U
        
       | staunton wrote:
       | This is a great technical achievement. It gives me some hope to
       | see that the various companies are able to invest into what is
       | still very basic science, even if it were mostly as vanity
       | projects for advertising purposes.
       | 
       | Quantum computing will surely have amazing applications that we
       | cannot even conceive of right now. The earliest and maybe most
       | useful applications might be in material science and medicine.
       | 
       | I'm somewhat disappointed that most discussions here focus on
       | cryptography or even cryptocurrencies. People will just switch to
       | post-quantum algorithms and most likely still have decades left
       | to do so. Almost all data we have isn't important enough that
       | intercept-now-decrypt-later really matters, and if you think you
       | have such data, switch now...
       | 
       | Breaking cryptography is the most boring and useless application
       | (among actual applications) of quantum computing. It's purely
       | adversarial, merely an inconsequential step in a pointless arms
       | race that we'd love to stop, if only we could learn to trust each
       | other. To focus on this really betrays a lack of imagination.
        
         | rgmerk wrote:
         | "Quantum computing will surely have amazing applications that
         | we cannot even conceive of right now..."
         | 
         | As best I understand, it's not clear yet whether quantum
         | computing will _ever_ have any practical applications.
         | 
         | Furthermore, there has already been a great deal of work
         | identifying potential applications for a quantum computer, so
         | I'd say we've got a fair idea of what you could do with one if
         | it ever exists.
        
           | gauge_field wrote:
           | The first (and important enough) practical application (apart
           | from breaking RSA) seems to be simulation of quantum systems.
           | But, this has some problems since alot of quantum models can
           | be simulated with Deep Learning methods (getting better) to a
           | good approximation. Probably, some quantum systems wont be
           | good for (classical) Deep Learning, those might be the first
           | candidates for application of quantum computers.
        
       | hi41 wrote:
       | What benchmark is being referred here?
       | 
       | >>Willow performed a standard benchmark computation in under five
       | minutes that would take one of today's fastest supercomputers 10
       | septillion (that is, 1025) years -- a number that vastly exceeds
       | the age of the Universe
        
         | dbrans wrote:
         | https://research.google/blog/validating-random-circuit-sampl...
        
       | hi41 wrote:
       | If error is getting corrected, doesn't it mean lower entropy? If
       | so where else is entropy increasing, if it is a valid question to
       | be asked.
        
         | roywiggins wrote:
         | Probably the same as normal chips: waste heat?
        
       | codeyperson wrote:
       | If we are in a simulation. This seems like a good path to getting
       | our process terminated for consuming too much compute.
        
         | prettyStandard wrote:
         | AI too.
         | 
         | I've followed Many worlds & Simulation theory a bit too far and
         | I ended up back where I started.
         | 
         | I feel like the most likely scenario is we are in a AI
         | (kinder)garden being grown for future purposes.
         | 
         | So God is real, heaven is real, and your intentions matter.
         | 
         | Obviously I have no proof...
        
           | swores wrote:
           | > " _and your intentions matter._ "
           | 
           | How do you reach that conclusion?
           | 
           | Characters in The Sims games technically have us human
           | players as gods, it doesn't mean that when we uninstall the
           | game those characters get to come into our earthly (to them)
           | heaven or have any consequences for actions performed during
           | the simulation?
        
             | prettyStandard wrote:
             | Sure it would. If you had Sims that went around killing
             | other Sims, there's no way in hell you would promote them,
             | or use their stimulated experiences as a bases for more
             | complex/serious projects.
             | 
             | I'm not deep into LLMs or AI safety right now, but if you
             | have a bad performing AI, you aren't going to use it as a
             | base for future work.
             | 
             | I was about to go to bed so I was rushing through my
             | initial comment... I was just trying to understand the
             | motivations for trying to create a stimulated reality...
             | Look at the resources we spend on AI?
        
               | djhn wrote:
               | One would have to be rather optimistic and patient if one
               | was to hold out hope for the humanity experiment to not
               | be destined for the Trash bin in this scenario, with our
               | track record.
        
         | a2128 wrote:
         | I doubt we would even register as a blip. The universe is
         | absolutely massive and there's celestial events that are
         | unthinkably massive and complex. Black hole mergers,
         | supernovae, galaxies merging. Hell, think of what chaos happens
         | in the inside of our own sun, and multiply that by 100 billion
         | stars in a galaxy, and multiply that by 100 billion galaxies.
         | Humanity is ultimately inconsequential.
        
           | swores wrote:
           | Surely it would depend on what the simulation actually was?
           | 
           | If you imagine simulations we can build ourselves, such as
           | video games, it's not hard to add something at the edge of
           | the map that users are prevented from reaching and have the
           | code send "this thing is massive and powerful" data to the
           | players. Who's to say that the simulation isn't actually
           | focussed on earth, and everything including the sun is
           | actually just a fiction designed to fool us?
        
             | prettyStandard wrote:
             | For me the interesting thing is, assuming miny worlds AND
             | simulation theory are both true. Many worlds would seem to
             | be a way to essentially run a/b tests on the simulation. So
             | how would you separate out/simplify details of your
             | simulation like far away planet stars and galaxies? The
             | speed of light and light cones, don't seem to be enough to
             | make a difference except for on the largest scales.
        
             | vlovich123 wrote:
             | The common trait that all hypothetical high-fidelity
             | simulated universes possess is the ability to produce high-
             | fidelity simulated universes. And since our current world
             | does not possess this ability, it would mean that either
             | humans are in the real universe, and therefore simulated
             | universes have not yet been created, or that humans are the
             | last in a very long chain of simulated universes, an
             | observation that makes the simulation hypothesis seem less
             | probable.
        
               | mrguyorama wrote:
               | >The common trait that all hypothetical high-fidelity
               | simulated universes possess is the ability to produce
               | high-fidelity simulated universes.
               | 
               | Where have you seen this?
        
               | vlovich123 wrote:
               | https://youtu.be/pmcrG7ZZKUc?t=220
               | 
               | If we're a simulation of a parent universe that is
               | exactly like us just of it's past or an alternate past,
               | then we likely should be able to achieve simulating our
               | own universe within ourselves. Otherwise we're not
               | actually a simulation.
               | 
               | There's another line of counter argument that various
               | results in QM and computing theory would suggest that
               | it's mathematically impossible for the universe to be
               | simulated on a computer (i.e. the parent universe would
               | have to look very different from ours vs ours in the
               | future). But I don't recall the arxiv paper.
        
               | mrguyorama wrote:
               | >If we're a simulation of a parent universe that is
               | exactly like us just of it's past or an alternate past
               | 
               | Yes, this is a MASSIVE and COMPLETELY UNTESTABLE if
               | 
               | Everything about simulation theory is like, science-
               | hostile or something it seems.
        
       | rkagerer wrote:
       | How much support infrastructure does this thing need? (eg.
       | Cryogenic cooling?) How big is a whole 'computer' and how much
       | power draw?
        
       | Havoc wrote:
       | So is it time to 100x key length on browsers yet or not?
        
         | bwesterb wrote:
         | About 8x just for key agreement and 40x for signatures. It's a
         | lot. For key agreement it's worth it, and now about 1/3 of
         | browsers in the wild use it.
         | http://radar.cloudflare.com/adoption-and-u...
        
       | jxdxbx wrote:
       | More misleading random circuit sampling benchmarks. All it proves
       | is that Google has built a quantum computer that does quantum
       | things.
        
       | webdevver wrote:
       | what is this actually useful for?
        
       | mvkel wrote:
       | Seems to coincide with Google's annual quantum announcement,
       | which has happened each fall since 2014
        
         | riku_iki wrote:
         | annual perf cycle probably
        
       | rvz wrote:
       | I don't usually say this often, unlike most here but this is
       | actually a huge achievement in quantum computing.
       | 
       | Yet another example as to why Google is essentially not going
       | anywhere or 'dying' as most have been proclaiming these days.
        
       | Uptrenda wrote:
       | 'It lends credence to the notion that quantum computation occurs
       | in many parallel universes, in line with the idea that we live in
       | a multiverse, a prediction first made by David Deutsch.'
       | 
       | Wait... what? Google said this and not some fringe crackpot?
        
       | GilKalai wrote:
       | In the past five years I participated in a project (with Yosi
       | Rinott and Tomer Shoham) to carefully examine the Google's 2019
       | "supremacy" claim. A short introduction to our work is described
       | here: https://gilkalai.wordpress.com/2024/12/09/the-case-
       | against-g.... We found in that experiment statistically
       | unreasonable predictions (predictions that were "too good to be
       | true") indicating methodological flaws. We also found evidence of
       | undocumented global optimization in the calibration process.
       | 
       | In view of these and other findings my conclusion is that Google
       | Quantum AI's claims (including published ones) should be
       | approached with caution, particularly those of an extraordinary
       | nature. These claims may stem from significant methodological
       | errors and, as such, may reflect the researchers' expectations
       | more than objective scientific reality.
        
         | janpmz wrote:
         | I've heared claims before that quantum computers are not real.
         | But I didn't understand it. Can anybody explain the reasoning
         | behind the criticism? Are they just simulated?
        
           | Rhapso wrote:
           | So the basics:
           | 
           | - quantum physics are real, this isn't about debating that.
           | The theory underpinning quantum computing is real.
           | 
           | - quantum annealing is theoretically real, but not the same
           | "breakthrough" that a quantum computer would be. Z-wave and
           | google have made these.
           | 
           | - All benchmark computations have been about simulating a
           | smaller quantum computer or annealer. which these systems can
           | do faster than a brute force classical search. These are
           | literally the only situation where "quantum supremacy"
           | exists.
           | 
           | - There is literally no claim of "productive" computation
           | being made by a quantum computer. Only simulations of our
           | assumptions about quantum systems.
           | 
           | - The critical gap is "quantum error correction", proof that
           | they can use many error prone physical qubits to simulate a
           | smaller system with lower error. There isn't proof yet that
           | is actually possible.
           | 
           | This result they are claiming, is they have "critical error
           | correction" is the single most groundbreaking result we could
           | have in quantum computing. Their evidence does not satisfy
           | the burden of proof. They also only claim to have 1 qubit,
           | which is intrinsically useless, and doesn't examine the costs
           | of simulating multiple interacting qubits.
        
           | sgt101 wrote:
           | I think that this is now a very fringe position - the
           | accumulation of reported evidence is such that if folks
           | were/are fooling themselves it would now be a case of an
           | entire community conspiring to keep things quiet. I mean,
           | it's not impossible that could happen, but I think it would
           | be extraordinary.
           | 
           | On the other hand the question is what does "real QC" mean?
           | The current QC's perform very limited and small computations,
           | they lack things like quantum memory. The large versions are
           | extremely impractical to use in the sense that they run for
           | 1000ths of a second and take many hours to setup for a run.
           | But that doesn't mean that the physical effects that they
           | use/capture aren't real.
           | 
           | Just a long long way from practical.
        
         | whoitwas wrote:
         | I'm skeptical only because they have AI in the name.
        
       | attentionmech wrote:
       | What does it mean when they say that the computations are
       | happening in multiverse? I didn't know we are that advanced
       | already :)
        
         | attentionmech wrote:
         | I don't know why i got downvoted. "It lends credence to the
         | notion that quantum computation occurs in many parallel
         | universes, in line with the idea that we live in a multiverse,
         | a prediction first made by David Deutsch." -- this is from the
         | article itself.
        
       | raminf wrote:
       | Relatives were asking for a basic explainer. Here's a good one by
       | Hannah Fry: https://youtu.be/1_gJp2uAjO0
        
       | crishoj wrote:
       | Take the announcement with a grain of salt. From German physicist
       | Sabine Hoffenfelder:
       | 
       | > The particular calculation in question is to produce a random
       | distribution. The result of this calculation has no practical
       | use. > > They use this particular problem because it has been
       | formally proven (with some technical caveats) that the
       | calculation is difficult to do on a conventional computer
       | (because it uses a lot of entanglement). That also allows them to
       | say things like "this would have taken a septillion years on a
       | conventional computer" etc. > > It's exactly the same calculation
       | that they did in 2019 on a ca 50 qubit chip. In case you didn't
       | follow that, Google's 2019 quantum supremacy claim was questioned
       | by IBM pretty much as soon as the claim was made and a few years
       | later a group said they did it on a conventional computer in a
       | similar time.
       | 
       | https://x.com/skdh/status/1866352680899104960
        
         | l33tman wrote:
         | TBH you need to take the _youtube influencer_ Sabine
         | Hoffenfelder with a bigger grain of salt. She has converted to
         | mainly posting clickbait youtube stuff over the last years
         | (unfortunately, she was interesting to listen to earlier).
         | 
         | The RCS is a common benchmark with no practical value, as is
         | stated several times in the blog announcement as well. It's
         | used because if a quantum computer can't do that, it can't do
         | any other calculation either.
         | 
         | The main contribution here seems to be what they indeed put
         | first, which is the error correction scaling.
        
           | falleng0d wrote:
           | I have observed the change in approach to use aggressive
           | (clickbaity) thumbnails, but I do think the quality of the
           | content has not changed.
           | 
           | And I can't blame her for adopting this trend, in many cases
           | it is the difference between surviving or not on YouTube
           | nowadays.
        
             | dexterdog wrote:
             | How would she not survive on YouTube? Would they block her
             | posts if she didn't use a misleading title and thumbnail
             | (shout-out to dearrow for those who despise this practice)?
        
               | mrguyorama wrote:
               | >Would they block her posts if she didn't use a
               | misleading title and thumbnail
               | 
               | So, the way youtube works is that every single creator is
               | in an adversarial competition for your attention and
               | time. More content is uploaded than can be consumed
               | (profitably, from Youtube's point of view). Every video
               | you watch is a "victory" for that video's creator, and a
               | loss for many others.
               | 
               | Every single time youtube shows you a screen full of
               | thumbnails, it's running a race. Whichever video you pick
               | will be shown to more users, while the videos you don't
               | pick get punished and downranked in the algorithm. If a
               | Youtube creator's video is shown to enough people without
               | getting clicked on, ie has a low clickthrough rate, it
               | literally stops being shown to people.
               | 
               | Youtube will even do this to channels you have explicitly
               | subscribed to, which they barely use as a signal for
               | recommendations nowadays.
               | 
               | Every single creator has said that clickbait thumbnails
               | have better performance than otherwise. If other creators
               | are using clickbait thumbnails, you will be at a natural
               | disadvantage if you do not. There are not enough users
               | who _hate_ clickbait to drive any sort of signal to the
               | algorithm(s).
               | 
               | If you as a creator have enough videos in a row that do
               | not do well, you will find your entire channel basically
               | stops getting recommended.
               | 
               | It's entirely a tragedy of the commons problem: If every
               | user stopped simultaneously, nobody would suffer, but any
               | defectors would benefit, so they won't stop
               | simultaneously.
               | 
               | Youtube itself could trivially stop this, but in reality
               | they love it, because they have absolutely run tests, and
               | clickbait thumbnails drive more engagement than normal
               | thumbnails. This is why they provide ample tooling to
               | creators to A/B test thumbnails, help make better
               | clickbait etc, and zero tooling around providing viewers
               | a way to avoid clickbait thumbnails, which would be
               | trivial to provide as an "alternative thumbnail" setting
               | for creators and viewers.
               | 
               | Sabine is literally driving herself down an anti-science
               | echochamber though. Maybe she can't see it, but it's very
               | clear from the outside what is happening. She has
               | literally said that "90% of the science that your tax
               | dollars pay for is bullshit" which is absurd hyperbole,
               | and something that a PHYSICIST cannot say about all
               | fields full stop. It's literally https://xkcd.com/793/
        
           | Closi wrote:
           | I think simplifying her to 'youtube influencer' is unfair -
           | she is a doctor of theoretical physics with a specialism in
           | quantum gravity who produces science content for youtube. She
           | knows the field enough to comment.
           | 
           | She doesn't even say that this isn't a big leap (she says
           | it's very impressive - just not the sort of leap that means
           | that there are now practical applications for quantum
           | computers, and that a pinch of salt is required on the claim
           | of comparisons to a conventional computer due to the 2019
           | paper with a similar benchmark).
        
           | pixelsort wrote:
           | As a counterpoint, she recently reviewed a paper in one of
           | her recent videos and completely tore it to shreds as
           | apparently the math was full of absolute nonsense.
           | 
           | This was a fascinating watch, and not the kind of content
           | that is easy to find. Besides videos like that one, I enjoy
           | her videos as fun way to absorb critical takes on interesting
           | science news.
           | 
           | Maybe she is controversial for being active and opinionated
           | on social media, but we need more science influencers and
           | educators like her, who don't just repeat the news without
           | offering us context and interpretation.
        
             | l33tman wrote:
             | I think I know which you mean, but TBH that paper read as
             | an AI auto-generated troll paper that any physics undergrad
             | should be able to dissect :) It was a bit fun to watch
             | though and sure sometimes you need to provide some fun
             | content as well!
        
           | zipy124 wrote:
           | Just because she is a YouTuber doesn't diminish her other
           | credentials, just as she is incetivised to do clickbait, so
           | are actual scientific communication outlets such as nature,
           | and the more clicky they are the more downloads and citation
           | they will acquire. Incentives change content but don't
           | directly detract from someone's expertise. See: the fact that
           | most universities now publish some lectures on YouTube, it
           | doesn't make the content any less true.
        
           | cowl wrote:
           | she was right the first time when they announced this in 2019
           | and this time even they admit in their own press release:
           | 
           | > Of course, as happened after we announced the first beyond-
           | classical computation in 2019, we expect classical computers
           | to keep improving on this benchmark
           | 
           | As IBM showed their estimate of classical computer time is
           | taken out of their a**es.
        
         | perching_aix wrote:
         | They explicitly cover all of these caveats in the announcement.
         | 
         | Problems that benefit from quantum computing as far as I'm
         | aware have their own formal language class, so it's also not
         | like you have to consider Sabine's or any other person's
         | thoughts and feelings on the subject - it is formally
         | demonstrated that such problems exist.
         | 
         | Whether the real world applications arrive or not, you can
         | speculate for yourself. You really don't need to borrow the
         | equally unsubstantiated opinion of someone else.
        
           | eigenket wrote:
           | The formal class is called BQP, in analogy with the classical
           | complexity clas BPP. BQP contains BPP but there is no proof
           | that it is stictly bigger (such a proof would imply P != NP).
           | There are problems in BQP we expect are not in BPP but its
           | not clear if there are any _useful_ problems in BQP and not
           | in BPP, other than essentially Shor 's algorithm.
           | 
           | On the other hand it's actually not completely necessary to
           | have a superpolynomial quantum advantage in order to have
           | some quantum advantage. A quantum computer running in
           | quadratic time is still (probably) more useful than a
           | classical computer running in O(n^100) time, even though
           | they're both technically polynomial. An example of this is
           | classical algorithms for simulating quantum circuits with
           | bounded error whose runtime is like n^(1/eps) where eps is
           | the error. If you pick eps=0.01 you've got a technically
           | polynomial runtime classical algorithm but it's runtime is
           | gonna be n^100, which is likely very large.
        
         | chvid wrote:
         | It would be interesting to see what "standard benchmark
         | computation" was used and what its implementation would like in
         | a traditional computer language.
         | 
         | Does anyone know?
        
         | vctrnk wrote:
         | Not to defend Google, but they end up saying much the same:
         | 
         | > The next challenge for the field is to demonstrate a first
         | "useful, beyond-classical" computation on today's quantum chips
         | that is relevant to a real-world application. We're optimistic
         | that the Willow generation of chips can help us achieve this
         | goal. So far, there have been two separate types of
         | experiments. On the one hand, we've run the RCS benchmark,
         | which measures performance against classical computers but has
         | no known real-world applications. On the other hand, we've done
         | scientifically interesting simulations of quantum systems,
         | which have led to new scientific discoveries but are still
         | within the reach of classical computers. Our goal is to do both
         | at the same time -- to step into the realm of algorithms that
         | are beyond the reach of classical computers and that are useful
         | for real-world, commercially relevant problems.
        
       | _joel wrote:
       | But can it run Crysis?
        
       | whiplash451 wrote:
       | Newbie's question: how far is the RCS benchmark from a more
       | practical challenge such as breaking RSA?
       | 
       | The article concludes by saying that the former does not have
       | practical applications. Why are they not using benchmarks that
       | have some?
        
         | Hilift wrote:
         | There are already companies selling 5,000+ qubit quantum
         | systems to the NSA. I would assume they are already using it
         | for that in the huge data center in Utah.
        
           | underdeserver wrote:
           | Which companies? And how big an RSA key do 5,000+ qubit
           | quantum systems break?
        
           | makeworld wrote:
           | Source?
        
         | wasabi991011 wrote:
         | Very far.
         | 
         | I'm not sure how to put it quantitatively, but my impression
         | from listening to experts give technical presentations is that
         | the breaking-rsa-type algorithms are a decade or two away.
         | 
         | This is very soon from a security perspective, as all you need
         | is to store current data and break it in the future. But it is
         | not soon enough to use for benchmarking current systems.
        
       | ramonverse wrote:
       | Can't wait for Google to release a breakthrough paper in 5 years
       | just for the authors to leave and build OpenQuant
        
       | machina_ex_deus wrote:
       | You learn a lot by what isn't mentioned. Willow had 101 qubits in
       | the quantum error correction experiment, yet only mere 67 qubits
       | in the random circuit sampling experiment. Why did they not test
       | random circuit sampling with the full set of qubits? Maybe when
       | turning on the full 101 set of qubits, qubits fidelity dropped.
       | 
       | Remember macroscopic objects have 10^23=2^76 particles, so until
       | 76 qubits are reached and exceeded, I remain skeptical that the
       | quantum system actually exploits an exponential Hilbert space,
       | instead of the state being classically encoded by the particles
       | somehow. I bet Google is struggling just at this threshold and
       | they don't announce it.
        
       | singlewind wrote:
       | Now, this is really make other countries nervous. Basically,
       | existing cryptography technology is in danger.
        
       | cubefox wrote:
       | Notice how the most interesting part, the image with their
       | quantum computing roadmap, has too low a resolution to read the
       | relevant text at the bottom. Come on Google.
        
       | EGreg wrote:
       | Any chance people will actually start reversing SHA1 hashes in
       | the next few years? Is there any quantum algorithm for reversing
       | one-way functions like that? (I mention SHA1 because they can
       | find collissions.)
        
       | yalogin wrote:
       | Trying to understand how compute happens in Quantum computers. Is
       | there a basic explanation of how superposition leads to
       | computing?
       | 
       | From chatgpt, "with n qubits a QC can be in a superposition of
       | 2^n different states. This means that QCs can potentially perform
       | computations on an exponential number of inputs at once"
       | 
       | I don't get how the first sentence in that quote leads to the
       | second one. Any pointers to read to understand this?
        
       | johndhi wrote:
       | Genuinely curious: does this make US regulators second-guess
       | breaking up Google? Having a USA company be the first to develop
       | quantum computing would be a major national security advantage.
        
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