[HN Gopher] More on whether useful quantum computing is "imminent"
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More on whether useful quantum computing is "imminent"
Author : A_D_E_P_T
Score : 37 points
Date : 2025-12-21 20:53 UTC (2 hours ago)
(HTM) web link (scottaaronson.blog)
(TXT) w3m dump (scottaaronson.blog)
| prof-dr-ir wrote:
| I am confused, since even factoring 21 is apparently so difficult
| that it "isn't yet a good benchmark for tracking the progress of
| quantum computers." [0]
|
| So the "useful quantum computing" that is "imminent" is not the
| kind of quantum computing that involves the factorization of
| nearly prime numbers?
|
| [0] https://algassert.com/post/2500
| bawolff wrote:
| I always find this argument a little silly.
|
| Like if you were building one of the first normal computers,
| how big numbers you can multiply would be a terrible benchmark
| since once you have figured out how to multiply small numbers
| its fairly trivial to multiply big numbers. The challenge is
| making the computer multiply numbers at all.
|
| This isn't a perfect metaphor as scaling is harder in a quantum
| setting, but we are mostly at the stage where we are trying to
| get the things to work at all. Once we reach the stage where we
| can factor small numbers reliably, the amount of time to go
| from smaller numbers to bigger numbers will be probably be
| relatively short.
| jvanderbot wrote:
| From my limited understanding, that's actually the opposite
| of the truth.
|
| In QC systems, the engineering "difficulty" scales very badly
| with the number of gates or steps of the algorithm.
|
| Its not like addition where you can repeat a process in
| parallel and bam-ALU. From what I understand as a layperson,
| the size of the inputs is absolutely part of the scaling.
| sfpotter wrote:
| The fact that it does appear to be so difficult to scale
| things up would suggest that the argument isn't silly.
| bahmboo wrote:
| I particularly like the end of the post where he compares the
| history of nuclear fission to the progress on quantum computing.
| Traditional encryption might already be broken but we have not
| been told.
| bawolff wrote:
| In a world where spying on civilian communication of
| adversaries (and preventing spying on your own civilians) is
| becoming more critical for national security interests, i
| suspect that national governments would be lighting more of a
| fire if they believe their opponents had one.
| littlestymaar wrote:
| I really doubt we are anywhere close to this when there has
| been no published legit prime factorization beyond _21_ :
| https://eprint.iacr.org/2025/1237.pdf
|
| Surely if someone managed to factorize a 3 or 4 digits number,
| they would have published it as it's far enough of
| weaponization to be worth publishing.
|
| The reality is that quantum computing is still very very hard,
| and very very far from being able what is theoretically
| possible with them.
| ktallett wrote:
| As someone that works in quantum computing research both academic
| and private, no it isn't imminent in my understanding of the
| word, but it will happen. We are still at that point whereby we
| are comparable to 60's general computing development. Many
| different platforms and we have sort of decided on the best next
| step but we have many issues still to solve. A lot of the key
| issues have solutions, the problem is more getting everyone to
| focus in the right direction, which also will mean when funding
| starts to focus in the right direction. There are snake oil
| sellers right now and life will be imminently easier when they
| are removed.
| andsoitis wrote:
| > it will happen.
|
| If you were to guess what reasons there might be that it WON'T
| happen, what would some of those reasons be?
| ktallett wrote:
| So in my view, the issues I think about now are:
|
| - Too few researchers, as in my area of quantum computing. I
| would state there is one other group that has any academic
| rigour, and is actually making significant and important
| progress. The two other groups are using non reproducible
| results for credit and funding for private companies. You
| have FAANG style companies also doing research, and the
| research that comes out still is clearly for funding. It
| doesn't stand up under scrutiny of method (there usually
| isn't one although that will soon change as I am in the
| process of producing a recipe to get to the point we are
| currently at which is as far as anyone is at) and
| repeatability.
|
| - Too little progress. Now this is due to the research focus
| being spread too thin. We have currently the classic digital
| (qubit) vs analogue (photonic) quantum computing fight, and
| even within each we have such broad variations of where to
| focus. Therefore each category is still really just at the
| start as we are going in so many different directions. We
| aren't pooling our resources and trying to make progress
| together. This is also where a lack of openness regarding
| results and methods harms us. Likewise a lack of automation.
| Most significant research is done by human hand, which means
| building on it at a different research facility often
| requires learning off the person who developed the method in
| person if possible or at worse, just developing a method
| again which is a waste of time. If we don't see the results,
| the funding won't be there. Obviously classical computing
| eventually found a use case and then it became useful for the
| public but I fear we may not get to that stage as we may take
| too long.
|
| As an aside, we may also get to the stage whereby, it is
| useful but only in a military/security setting. I have worked
| on a security project (I was not bound by any NDA
| surprisingly but I'm still wary) featuring a quantum setup,
| that could of sorts be comparable to a single board computer
| (say of an ESP32), although much larger. There is some value
| to it, and that particular project could be implemented into
| security right now (I do not believe it has or will, I
| believe it was viability) and isn't that far off. But that
| particular project has no other uses, outside of the
| military/security.
| ecshafer wrote:
| Wouldn't the comparison be more like the 1920s for computing.
| We had useful working computers in the 1940s working on real
| problems doing what was not possible before hand. By the 1950s
| we had computers doing Nuclear bomb simulations and the 1960s
| we had computers in banks doing accounting and inventory. So we
| had computers by then, not in homes, but we had them. In the
| 1920s we had mechanical calculators and theories on computation
| emerging but not a general purpose computer. Until we have a
| quantum computer doing work at least at the level of a digital
| computer I can't really believe it being the 1960s.
| ktallett wrote:
| I'm not going to pretend that I am that knowledgeable on
| classic computing history from that time period. I was
| primarily going off the fact the semi conductor was built in
| the late 40's, and I would say we have the quantum version of
| that in both qubit and photonic based computing and they work
| and we have been developing on them for some time now. The
| key difference is that there are many more steps to get to
| the stage of making them useful. A transistor becamse useful
| extremely quickly and well in Quantum computing, these just
| haven't quite yet.
| tokai wrote:
| Not to be snarky, but how is it comparable to 60's computing?
| There was a commercial market for computers and private and
| public sector adoption and use in the 60s.
| ktallett wrote:
| There is private sector adoption and planning now of specific
| single purpose focused quantum devices in military and
| security settings. They work and exist although I do not
| believe they are installed. I may be wrong on the exact date,
| as my classical computer knowledge isn't spot on. The point I
| was trying to make was that we have all the bits we need. We
| have the ability to make the photonic quantum version (which
| spoiler alert is where the focus needs to move to over the
| qubit method of quantum computing) of a transistor, so we
| have hit the 50's at least. The fundamentals at this point
| won't change. What will change is how they are put together
| and how they are made durable.
| eightysixfour wrote:
| Did anyone else read the last two paragraphs as "I AM NOT ALLOWED
| TO TELL YOU THINGS YOU SHOULD BE VERY CONCERNED ABOUT" in bright
| flashing warning lights or is it just me?
| William_BB wrote:
| Just you
| ktallett wrote:
| It is more, many companies can't do what they claim to do, or
| they have done it once at best and had no more consistency. I
| sense most companies in the quantum computing space right now
| are of this ilk. As someone that works in academic and private
| quantum computing research, repeatability and methodology are
| severely lacking, which always rings alarm bells. Some
| companies are funded off the back of one very poor quality
| research paper, reviewed by people who are not experts, that
| then leads to a company that looks professional but behind the
| scenes I would imagine are saying Oh shit, now we actually have
| to do this thing we said we could do.
| bahmboo wrote:
| I don't think he is saying that. As I said in my other comment
| here I think he is just drawing a potential parallel to other
| historic work that was done in a private(secret) domain. The
| larger point is we simply don't know so it's best to act in a
| way that even if it hasn't been done already it certainly seems
| like it will be broken. Hence the move to Post-Quantum
| Cryptography is probably a good idea!
| belter wrote:
| I ran it through ROT13, base64, reversed the bits, and then
| observed it....The act of decoding collapsed it into ...not
| imminent...
| tromp wrote:
| I realize this is a minority opinion, and goes against all
| theories of how quantum computing works, but I just cannot
| believe that nature will allow us to reliably compute with
| amplitudes as small as 2^-256. I still suspect something will
| break down as we approach and move below the planck scale.
| Aardwolf wrote:
| Once quantum computers are possible, is there actually anything
| else, any other real world applications, besides breaking crypto
| and number theory problems that they can do, and do much better
| than regular computers?
| comicjk wrote:
| Yes, in fact they might be useful for chemistry simulation long
| before they are useful for cryptography. Simulations of quantum
| systems inherently scale better on quantum hardware.
|
| https://en.wikipedia.org/wiki/Quantum_computational_chemistr...
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