[HN Gopher] Observation of zero resistance above 100 K in Pb10-[...
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       Observation of zero resistance above 100 K in Pb10-[?]Cu[?](PO4)6O
        
       Author : segfaultbuserr
       Score  : 749 points
       Date   : 2023-08-03 00:43 UTC (22 hours ago)
        
 (HTM) web link (arxiv.org)
 (TXT) w3m dump (arxiv.org)
        
       | pyeri wrote:
       | As a lay person not graduated in STEM subjects, can someone ELIFY
       | how is this research useful to society?
        
         | beanjuice wrote:
         | This exact paper is the newest progress on recent hype
         | regarding a semi-trustworthy not-peer-reviewed study claiming
         | 'superconductors at room temperature'.
         | 
         | 'Superconductors at room temperature' are cool because they
         | would answer questions like "How would we get solar power from
         | [your local desert] everywhere else for free?" and "How are we
         | going to use MRIs when the helium runs out?" as two examples.
        
       | nmca wrote:
       | I wish we had real money prediction markets. Afaict it would be
       | legal to run such a business in the UK.
        
         | parineum wrote:
         | I remember seeing something like this that ran on bitcoin a
         | while ago. It was completely user driven and lines were
         | dynamically calculated by the action. I'm not sure how the
         | resolutions to the bets were determined exactly, perhaps there
         | was a requirement of a third party indicator of some sort, I
         | don't recall.
        
       | jesprenj wrote:
       | Is this one also written in Word so it automatically loses LaTeX-
       | credibility, as was commented under the first paper? (:
        
         | ant6n wrote:
         | Maybe some people wanna focus on the work and not on the geek
         | cred.
         | 
         | (I need to write some thesis like thing soon, like 15 years
         | after my masters thesis that was written in latex, and do I
         | really want to bother setting latex up again and futz with
         | templates and fight for correctly positioned figures, or just
         | use Word and be done with it?)
        
           | marcosdumay wrote:
           | > just use Word and be done with it?
           | 
           | One don't "just" use word, and it's certainly never done
           | with. Unless you found a room temperature superconductor and
           | half the people will simply not care if you wrote it in a
           | piece of paper (yet half will care... for some reason), you
           | will have to spend all your time fixing formatting issues and
           | keeping things on their correct state.
           | 
           | I was stupid enough to write a paper in Word once. Given the
           | choice, I will never repeat the mistake.
        
           | chungy wrote:
           | Give TeXmacs a shot.
        
         | ramraj07 wrote:
         | I would have said latex gatekeepers are the worst, but now I
         | know eMacs geeks so no. Or was it vim? Can never tell!
        
           | robotresearcher wrote:
           | 'eMacs'? It's LaTeX that has the self-conscious
           | capitalization!
        
             | astrange wrote:
             | There was a thing called an eMac once, it wasn't a text
             | editor though.
        
       | progrus wrote:
       | It's real, it works, the Navy has a linked patent from 2017.
       | 
       | The UFOs are a PSYOP.
        
         | declan_roberts wrote:
         | The Navy does have a patent for a "lead zirconate titanate"
         | super conductor which does sound awfully similar to what's
         | described in LK-99.
         | 
         | https://phys.org/news/2019-02-navy-patent-room-temperature-s...
        
           | drtgh wrote:
           | From the same author https://doi.org/10.2514/6.2019-0869 ,
           | 2019 Salvatore Cezar Pais
           | 
           | > It is important for the PZT coating to undergo a polarizing
           | (poling) treatment prior to RTSC enablement, so that optimal
           | domain alignment is obtained within the ceramic coating, by
           | subjecting the coating to a strong dc current electric field,
           | slightly below the Curie temperature (approx.200 0C, but
           | possibly as high as 360 0C, depending on PZT ceramic
           | composition). Furthermore, to increase the probability of
           | vibration in one particular direction, as well as to
           | alleviate the brittle nature of the ceramic material, it may
           | be necessary to make the 'metallic' wire coating out of a
           | composite PZT and highly conductive polymer, such as
           | p-Terphenyl [4]. Another option is to sandwich the PZT
           | ceramic in between two layers of aluminum, resulting in a
           | wire design which may be planar rather than cylindrical in
           | nature. This composite coating design would amplify
           | piezoelectrically-induced vibrations and possibly render them
           | unidirectional.
           | 
           | From LK99 rumors:
           | 
           | > At the beginning of 2020, Ji-Hoon Kim continued to do
           | experiments as usual, suddenly he found a huge peak, he
           | repeated the test + looked at his notes. But didn't find any
           | special points. He started looking through the lab videos. He
           | finally realized that the tube of sample came out with cracks
           | on the quartz tube, and he hit his elbow on the table while
           | transferring the sample out to the electronic scale.
           | Introducing oxygen at the right moment + a violent impact
           | would change the structure of the lead apatite crystals being
           | formed.
           | 
           | May be something, may be nothing,
           | 
           | S.C.Pais: "to increase the probability of vibration in one
           | particular direction"
           | 
           | S.C.Pais: "piezoelectrically-induced vibrations [ and
           | possibly render them unidirectional]"
           | 
           | LK99: "oxygen at the right moment + violent impact would
           | change the structure of the lead apatite crystals being
           | formed"
        
             | yreg wrote:
             | This person has an absurd patent track record
             | https://en.wikipedia.org/wiki/Salvatore_Pais
        
           | FrustratedMonky wrote:
           | Man. I hope it isn't. That would be sad, all this was
           | happening, and nobody had found the old study. Surely not.
        
           | progrus wrote:
           | Ding ding.
        
           | unsupp0rted wrote:
           | > The application claims that a room-temperature
           | superconductor can be built using a wire with an insulator
           | core and an aluminum PZT (lead zirconate titanate) coating
           | deposited by vacuum evaporation with a thickness of the
           | London penetration depth and polarized after deposition.
           | 
           | > An electromagnetic coil is circumferentially positioned
           | around the coating such that when the coil is activated with
           | a pulsed current, a non-linear vibration is induced, enabling
           | room temperature superconductivity.
        
           | adrian_b wrote:
           | Except for the fact that both materials contain lead, there
           | is no resemblance.
           | 
           | Lead is one of the best superconductors among pure metals,
           | whose superconductivity has been already discovered 110 years
           | ago, in 1913.
           | 
           | Nevertheless, there is absolutely no relationship between the
           | superconductivity of pure lead and the alleged
           | superconductivity of lead zirconate titanate and the alleged
           | superconductivity of lead phosphate doped with copper.
           | 
           | They have very different crystal structures and behaviors of
           | the free electrons (i.e. electronic band structures).
           | 
           | Only if in the PZT samples used by the Navy there would have
           | been some impurities, without the knowledge of the
           | researchers, causing contraction of the crystal when
           | substituting the big lead atoms, then there would have been a
           | similar mechanism to what is claimed now.
           | 
           | If this mechanism is proven to really work, then it could
           | also work in other crystals with big ions, like lead or
           | baryum, perhaps even in PZT.
        
       | danbrooks wrote:
       | Encouraging evidence that the recent work on room temperature
       | superconductivity might be real!
       | 
       | Still waiting for confirmation from multiple labs.
        
       | wsieroci wrote:
       | Could someone explain why this is important? What is the
       | consequence of the existence of Superconductors like that?
        
         | kvandy wrote:
         | My understanding is that this unlocks future-tech... Post
         | quantum computing, hyper efficient rail tech, fast charging
         | batteries, etc. Pretty neat stuff, and even cooler to be able
         | to follow this as it develops.
        
           | [deleted]
        
         | dgoldstein0 wrote:
         | The biggest near future tech for superconductors: fusion power.
         | 
         | One huge area of exploration for fusion power is tokamok
         | reactor design, which requires a very strong magnetic field to
         | confine plasma within a round shape - typically a torus, though
         | I think I read of one spherical shell.
         | 
         | I suppose these don't necessarily need room temperature super
         | conductors, but cheaper and easier to manufacture
         | superconducting materials to use as the magnets could make a
         | huge difference. And I do wonder if allowing higher
         | temperatures could aid in the operability of these future
         | devices.
         | 
         | https://spectrum.ieee.org/fusion-2662267312 is one I read about
         | recently, using YBaCuO as the superconducting electromagnet.
         | Definitely sounds bottlenecked on production of it.
         | 
         | Fusion power, as any energy source that massively increases the
         | amount of energy humans can harness, could be planet changing.
        
           | coderenegade wrote:
           | I think energy storage, motors / accelerators and weapons
           | would come first. A superconducting linear motor would
           | probably also make for a great cannon.
        
             | DoingIsLearning wrote:
             | If we are talking DARPA money, I think working out how to
             | build IC sensors using this stuff would be much quicker to
             | reach manufacturing then a large scale motor winding.
             | 
             | I am sure defense folks would have a field day with new
             | sensors with virtually no thermal noise.
        
             | ssijak wrote:
             | shooting satellites to orbit with cannons
        
             | dgoldstein0 wrote:
             | Yeah, you're probably right - fusion has a lot of hard
             | problems to solve. But for it, cheaper superconductors
             | could be the game changer we need. For these other
             | things... We already have energy storage, motors, weapons
             | etc. It's certainly reasonable to think we could build
             | better ones but I'm more excited for fusion, as it has the
             | ability to solve climate change and provide cheap
             | electricity to the billions who don't yet have it at the
             | same time, probably resulting in double digit economic
             | growth in many places.
        
         | n2d4 wrote:
         | In the most ELI5 way possible, a superconductor is a material
         | that doesn't lose any energy or produce heat when used as a
         | cable/wire, and at the same time also a very strong magnet.
         | 
         | MRIs and powerlines are more obvious applications, but
         | theoretically you can do a lot of cool stuff (batteries with
         | zero energy loss, heat-efficient computers, etc [1]). If true,
         | LK-99 would allow these things to happen at room temperature
         | instead of negative whatever degrees, making them much more
         | useful.
         | 
         | [1]
         | https://en.m.wikipedia.org/wiki/Technological_applications_o...
        
         | booleandilemma wrote:
         | I like this HN comment explaining it:
         | https://news.ycombinator.com/item?id=36978704
        
       | daemontus wrote:
       | I see a lot of _" This must be real, why would labs publish this
       | if they don't think it's real, they have nothing to gain."_
       | sentiment on HN lately. Or _" Researcher's career would be ruined
       | if they falsely claim to replicate."_, and so on. I also want to
       | believe! But I should add a bit of skepticism to the hype :)
       | 
       | - "this could ruin their career": Depends. If they posted
       | completely fake numbers or intentionally fake videos. Sure, that
       | would be bad. But none of this is peer reviewed, and all of this
       | can be retracted. A contaminated sample? Oops, retract. Bad
       | measurement methodology? Oops, retract. Sure, _somebody_ will
       | remember that you made the controversial paper in the first
       | place, but as long as you are not provably fabricating, a lot can
       | be attributed to  "an honest error". There are tons of peer
       | reviewed papers out there with errors that completely change the
       | outcome. Does not mean the authors are "finished".
       | 
       | - "they have nothing to gain": Oh, they absolutely do. While
       | "science should be fully objective", funding agencies very much
       | aren't. Obviously, just like VC funding, science funding is not a
       | complete coin toss. But having "the right" team and background is
       | often as important as the idea itself. One way to get the right
       | background is to "touch shoulders with the giants" and one way to
       | get the right team is to be highly visible and attract talent.
       | 
       | So overall, if LK99 is _eventually_ shown to be a superconductor
       | by someone else, you have a lot to gain, even if your own initial
       | study is not perfect.
       | 
       | Let's say your team synthesised something. It looks like LK99 and
       | it has _some_ properties that are not really superconducting but
       | at least a bit unusual. This clearly isn 't what you hoped for.
       | Now, do you run a bunch of other controls to see if it is some
       | form of contamination, process error, combination of both... or
       | do you publish a vague click-bait paper on ArXiv and hope that
       | other results will somewhat align with yours?
       | 
       | Finally, I'm not claiming this paper or any other paper
       | intentionally published untrue or misleading results. Just that
       | scientists are also people. They have FOMO, they follow trends,
       | they see what they want to see. As always, big claims require big
       | evidence, and so far we don't really have that. But that does not
       | mean there isn't some truth to the big claims :)
        
         | jpambrun wrote:
         | A contaminated sample that materially change the composition
         | but still yield a superconductor would be a novel finding.
         | 
         | An error in manipulation leading to an external communication
         | on something this high profile is sure to affect your career.
         | It's like a biologist claiming to have found evidence
         | extraterrestrial life and having to retract. I think I would
         | consider hara-kiri..
        
           | daemontus wrote:
           | But the thing is... except for the original authors, none of
           | these papers so far _really_ claim to have a room-temperature
           | superconductor, right? They claim  "simulated band structure
           | with low Fermi level", or "unusual levels of diamagnetism",
           | or "almost zero resistance up to -100degC (but lack of phase
           | transition)", etc.
           | 
           | Yes, retracting these is still shameful, but it's not a "we
           | found extraterrestrial life" claim. It's a "we received weird
           | signals from a nebula that we don't understand so far" claim.
           | 
           | And yes, a lot of supporting but inconclusive evidence is
           | still supporting evidence. My point is not that (most)
           | scientists would risk lying about replicating a
           | superconductor, but rather that uncertain or inconclusive
           | results with a solid chunk of plausible deniability in a
           | rapidly evolving environment go a long way towards being "in
           | the room where it happened".
        
             | jpambrun wrote:
             | This is not my area of expertise, but as a former scientist
             | (at least at the PhD and postdoc level) I would not stake
             | my credibility on something without being 1000% sure on a
             | normal day, let alone when the topic is extraterrestrial
             | life or room temperature superconductors.
             | 
             | Also, it's not true at all the retraction have no
             | consequences. It is an indelible mark of shame.
        
             | cthalupa wrote:
             | I wouldn't bet on LK99 being a RTAPS but "Replicating a
             | bunch of weird shit that we don't really understand that at
             | least somewhat align with the possibility" really isn't a
             | damning position to be in when the starting point is "The
             | team says they only get a working sample about 10% of the
             | time and everyone else is working off of pretty meh
             | instructions on how to replicate"
        
           | [deleted]
        
       | lifthrasiir wrote:
       | I'm very much conservative about this paper because while the
       | graph in Fig. 3a says $T_c^{zero}$ being 110 K, the "zero"
       | resistance is actually only 1e-5 O (!) and even if the sample is
       | possibly superconducting its critical temperature would be much
       | lower than 110 K anyway. I'm aware of the difficulty in obtaining
       | larger samples, but the label in that graph is really misleading
       | regardless.
        
         | nukros wrote:
         | The random jumps in the resistivity around 250 K suggests that
         | there is very bad contact resistance or a possible alternate
         | current path. The drop in resistance doesn't look like a
         | typical phase transition (it is very broad in temperature). My
         | guess would be that the voltage leads are not very well
         | connected to the region of the sample that the current is
         | flowing through. This could actually give a drop in the
         | measured voltage (and therefore "resistance") even though the
         | actual resistance is increasing as the sample is cooled. It
         | would be interesting if they also included two-point resistance
         | across the current leads.
        
           | segfaultbuserr wrote:
           | One of the authors commented in their previous video pre-
           | announcement that they suspect it was a probe cleanliness
           | problem, which they would investigate later.
        
             | throwawaylinux wrote:
             | Is this kind of thing typical for experiments working to
             | confirm such significant results, or is there a mad rush to
             | publish?
             | 
             | Do you really get a lot of prestige from confirming
             | somebody else's result? I would have thought the risk to
             | reputation from sloppy work would far outweigh it (see: the
             | cold fusion shenanigans).
        
               | ianai wrote:
               | Probably a lab that confirms any piece of it will get a
               | significant share of attention and acclaim.
               | 
               | I heard the research group got scooped by a former
               | researcher. Former researcher outed them before they were
               | ready for all the relevant questions. Not a particularly
               | good thing to do for a career to out colleagues like
               | that.
        
               | agnosticmantis wrote:
               | In this particular case I'd be less cynical as even
               | laypersons are anxious to know what's the result. So it's
               | natural that scientists that have the lab equipment are
               | rushing to replicate or falsify the results.
        
               | throwawaylinux wrote:
               | > Probably a lab that confirms any piece of it will get a
               | significant share of attention and acclaim.
               | 
               | Why is that though? They're taking a discovery that
               | somebody else came up with, and (mostly) follow a recipe
               | they're given.
               | 
               | I mean if they were synthesizing a theorized substance or
               | significantly improving its production, or measuring an
               | effect that was previously undetectable by known
               | instruments and experiments then those things would
               | deserve acclaim on their own.
               | 
               | Not saying they aren't good scientists and labs working
               | on this or reproducing is worthless, the reward just
               | doesn't seem big enough not to be meticulous about it. If
               | you're right then you'll be one of the dozens of labs
               | that reproduced it and all credit goes to original
               | discoverers. If you're wrong you'll be the ones who
               | bungled the experiment and share just about equal blame.
        
               | soerxpso wrote:
               | It demonstrates efficiency and ability to do something
               | complicated and challenging under time pressure. Maybe it
               | shouldn't be considered a big academic achievement, but
               | it's definitely an impressive practical achievement.
               | 
               | I don't think that being wrong looks bad. There are a lot
               | of understandable ways to be wrong, and it's not like any
               | of these labs are being dishonest about their level of
               | confidence (you can't really be "wrong" if you're not
               | overcommitted to a stance).
        
               | throwawaylinux wrote:
               | It's having these suspected dirty probes that they
               | haven't investigated yet which is in particular what I'm
               | talking about though. Since they made no particular
               | experimental or theoretical breakthrough here, I just
               | would have thought they would want to be meticulous about
               | confirming an unexpected result. As you say, the point is
               | to show their experimental capabilities.
               | 
               | > I don't think that being wrong looks bad. There are a
               | lot of understandable ways to be wrong, and it's not like
               | any of these labs are being dishonest about their level
               | of confidence (you can't really be "wrong" if you're not
               | overcommitted to a stance).
               | 
               | I'm not in the field, but I would have thought it would
               | look pretty bad if they were wrong and their experiment
               | had obvious sloppy practices.
               | https://en.wikipedia.org/wiki/Cold_fusion apparently that
               | sunk a few reputations.
               | 
               | I completely understand a private rush to replicate for
               | the purpose of building on it and making new discoveries,
               | but just to put rush out a confirm paper? I suspect it's
               | less about demonstrating actual efficiency and ability
               | and more about the paper mill.
        
               | saithound wrote:
               | It is hard work, but relatively easy work proportional to
               | the possible rewards, and has very few downsides:
               | 
               | 1. An early preprint provides instant press coverage for
               | the researchers, their lab and the entire university.
               | Such opportunities are rare: I worked in academia full-
               | time for decades, and never had an opportunity to do some
               | fixed amount of well-understood work that guarantees an
               | appearance in the national press. Such an appearance is
               | very useful in inter-departmental politics, not to
               | mention when dealing with government organizations
               | staffed by non-researchers. E.g. if "biggest newspaper in
               | country X" reported about your research, that by itself
               | ensures that you won't have to apply for "shitty academic
               | visitor visa to the UK", but can credibly apply for a
               | "global talent, go straight to indefinite leave to
               | remain" one instead. And if the effect turns out to be
               | real, and you managed to reproduce the effect while lots
               | of others tried and failed, that's going to look really
               | good on the grant application where you have to explain
               | why your lab is the best place to spend money earmarked
               | for superconductor research. This is unlike other
               | replication papers, which are not usually the "gets
               | reported on national media kind, or even "many others
               | tried and failed" kind, but usually the "nobody else
               | cared" type.
               | 
               | 2. The article will definitely garner some citations.
               | Even if LK-99 does not pan out, there will be many many
               | survey articles written about what's unfolding right now,
               | and they will all definitely cite the earliest
               | replications. Moreover, it doesn't matter if your first
               | preprint has shit writing: you'll still be cited if the
               | final version gets accepted 4 months from now, after many
               | rewrites. This is unlike most random "reproduction"
               | papers, which are unlikely to get published, much less
               | cited. So reproducing LK-99 is in fact a good way to
               | increase h-index.
               | 
               | 3. As long as you don't do anything fraudulent, there's
               | very little career risk involved with being fast-and-
               | loose in a preprint. If LK-99 pans out you're definitely
               | in the clear. If it doesn't, well, as every second
               | comment here mentions, materials science is difficult,
               | honest mistakes are easy to make, even reproducing
               | results is incredibly finicky and hard. It's not like
               | your lab was the only one making anomalous observations.
               | Chances are nobody's going to care if you were involved
               | in a false positive replication. In fact, probably
               | nobody's going to read and scrutinize your whole
               | publication list when hiring or promoting you, but
               | they'll definitely care about your citation metrics. This
               | is unlike most other reproduction papers, where you
               | wouldn't get many citations even if you managed to
               | publish, because nobody cared.
               | 
               | All in all, dropping everything else and working on this
               | right now is a good strategy, even for investigators in
               | prestigious labs that would otherwise not bother with
               | reproduction papers.
        
               | jacquesm wrote:
               | In science the fights are so fierce because the stakes
               | are so small...
        
               | CamperBob2 wrote:
               | Typically a valid comment in academia at large, but not
               | when high-temperature superconductors are the subject of
               | the fight. If these claims pan out, these guys may be the
               | next Andy Viterbi or Ray Stata.
        
               | Qem wrote:
               | > I heard the research group got scooped by a former
               | researcher. Former researcher outed them before they were
               | ready for all the relevant questions. Not a particularly
               | good thing to do for a career to out colleagues like
               | that.
               | 
               | Either this or they tried to deny proper authorship to
               | the guy, that antecipated the publishing in self-defense.
               | It's early to point who was the party at fault, without
               | proper investigation.
        
         | peyton wrote:
         | Spec sheet says 10 uohm is as low as their probe goes.
        
         | pythonguython wrote:
         | I believe certain it is near impossible to actually measure
         | truly zero resistance. Instead, a sudden drop near Tc, combined
         | with the meissner effect is what confirms superconductivity.
        
         | segfaultbuserr wrote:
         | The resistance curve stopped at 1e-5 O because it has nearly
         | reached the resolution limit of their instrument. Using 4-wire
         | Kelvin sensing, the measurement current was 1 mA, the voltage
         | read-out across the material was around 1 to 10 nanovolts -
         | this is around the scale that some of the world's best general-
         | purpose voltmeters can measure down to. The authors assumed
         | that the negligible voltage drop, combined with the abrupt drop
         | and flattening of the resistance vs temperature curve is
         | already a convincing-enough indication of superconductivity.
         | 
         | Hopefully more rigorous testing will be done by one of the
         | teams later.
        
           | lifthrasiir wrote:
           | Which is indeed their argument. But in that case they haven't
           | proved that $T_c^{zero}$ = 110 K, they only proved that
           | $T_c^{zero}$ < 110 K. (And I should also note that
           | $T_c^{zero}$ doesn't imply the actual critical temperature
           | $T_c$, while the title strongly suggests so.)
        
           | amelius wrote:
           | Curious, why didn't they use a larger current for the
           | measurement?
        
             | segfaultbuserr wrote:
             | Who knows... Too afraid to damage their only sample?
        
         | kurthr wrote:
         | Well, it's at a 1mA test current (I'm assuming a 4 point probe
         | to mitigate contact resistance) so 10u Ohm would give a 10nV DC
         | signal. That's a pretty small voltage signal and comparable to
         | a fairly standard chopper stabilized instrumentation amp rms
         | noise at room temp near DC.
         | 
         | I'm not sure whether higher currents are all that reasonable.
         | Cooling the precision amp is an option to reduce the noise
         | figure, but at that point you'll want optical isolation and
         | battery supply too.
         | 
         | https://www.analog.com/media/en/training-seminars/tutorials/...
        
           | guraf wrote:
           | [flagged]
        
             | kurthr wrote:
             | Yeah, I ran low temp STM/BEEM systems in UHV for 4 years at
             | JPL's MDL.
             | 
             | I assume you know what that means. Even today low frequency
             | nV signals are still hard. Did you know you can do zero-
             | bias tunneling sensing?
        
               | robbiep wrote:
               | Glorious to watch
        
           | throwaway849755 wrote:
           | A comment above says they are using
           | https://www.qdusa.com/products/ppms.html with the DC 4-wire
           | option.
           | 
           | All my instincts would prefer they were using the AC 4-wire
           | option, given any reason to question results, and/or issues
           | with contact effects, etc.
        
             | kurthr wrote:
             | Thanks! That's great information. We had to make our own,
             | but it's good to see that there are decent off the shelf
             | systems. I agree that contact resistance on these tiny
             | samples has got to be a huge issue (can they use mercury?).
             | However, what I've seen suggests that even the low
             | frequency AC measurements are more complex due to
             | capacitive coupling effects. However, narrow bandwidth
             | lock=in should improve noise... the equipment still just
             | claims 10u Ohm.
        
       | tines wrote:
       | Isn't it a faux pas to put the degrees-symbol after the unit K?
        
         | extraduder_ire wrote:
         | It's incorrect, yes. (about as incorrect as saying you're "1.8
         | degrees meters tall") But also, that's "U+2218 RING OPERATOR"
         | on the page, not "U+00B0 DEGREE SIGN" but that may just be a
         | typo.
        
         | Nifty3929 wrote:
         | Yes
        
         | tnecniv wrote:
         | Clearly K is an element of some kind of algebraic structure
         | here
        
           | DaiPlusPlus wrote:
           | Ah yes, K, the Potassium Constant
        
       | mmastrac wrote:
       | I'm impressed that Pb10-[?]Cu[?](PO4)6O is completely
       | representable in Unicode.
        
       | ibic wrote:
       | So this almost means the holy grail has been found or we are
       | pretty close?
        
       | gandik wrote:
       | This is _so_ reminiscent of what happened after Fleischmann  &
       | Pons. Labs attempting to replicate saw this property, or that
       | property, but never the whole, unequivocal picture.
       | 
       | Here we have a room temperature superconductor that isn't a
       | superconductor at room temperature. A sample that has no measured
       | Meissner Effect at any temperature. And the authors admit that
       | some (many?) of the samples tested out as semiconductors.
       | 
       | Also, they don't happen to mention how they measured resistance.
       | 1mA current, yes, but what equipment? And what setup? Micro-
       | measurement of resistance is _hard_. We really need to know more
       | about that.
        
         | rsfern wrote:
         | I agree with your first points, but the methods section states
         | (somewhat unclearly) that they used this 4 point probe setup
         | 
         | https://www.qdusa.com/products/ppms.html
         | 
         | I have more questions about that, like why not calculate sheet
         | resistivity instead of just showing that the resistance hits
         | the noise floor?
        
         | segfaultbuserr wrote:
         | I agree that the setup is not satisfactorily documented.
         | 
         | > _but what equipment?_
         | 
         | But at least this individual question is actually included in
         | the paper. It was the _Physical Property Measurement System_
         | (PPMS), manufactured by Quantum Design Inc. From the photo, one
         | can clearly see that the DC resistance test fixture was used.
         | 
         | https://www.qdusa.com/products/ppms.html
        
         | crote wrote:
         | To me the biggest difference is the _three_ theoretical papers,
         | including from very reputable sources, all showing that a)
         | there is indeed something weird going on with this material and
         | b) due to the unusual configuration it is going to be tricky to
         | manufacture.
         | 
         | Fleischmann & Pons was never supported by theory and was
         | essentially a "we measured something and have no idea what is
         | going on". LK-99 is more of a "the theory says something
         | interesting will probably happen, and we believe we measured it
         | in some samples but can't reliably reproduce it".
        
         | carabiner wrote:
         | I read more about F&P and wow, there are striking similarities.
         | The duo probably weren't fraudsters. No intentional deception
         | in their work was ever found, so not like Hendrik Schon. They
         | were basically forced to make their results public by their
         | university, but it was very premature and they should have
         | waited ten years. They were 100% legit, top researchers in the
         | field before all this, and well after the scandal many
         | scientists continued research in avenues initiated by F&P's
         | original experiments (with little success). I can totally see
         | LK-99, once it fails replication in a month, leading to more
         | research but probably not yielding the holy grail.
        
         | highwaylights wrote:
         | I see. So what you're saying is that if we replace the
         | palladium with LK-99 then cold fusion is back on?
         | 
         | You know, because hype.
         | 
         | This is, as the kids say, very bullish.
        
           | hindsightbias wrote:
           | I'd be happy if it just makes UFOs in focus.
        
       | homeslice23 wrote:
       | [dead]
        
       | nyc_pizzadev wrote:
       | Worth noting that the sample used did not produce a Meissner
       | effect, but was still superconductive at ~100K.
       | 
       | > To further verify the superconducting properties, we conducted
       | magnetic measurements on the sample, but unfortunately, no
       | obvious Meissner signal was observed, indicating that the
       | superconducting volume fraction of the sample may be very small.
       | The preparation of high-purity samples are still a challenging
       | task.
        
         | klimt wrote:
         | This is one of my key takeaways as well. It's a shame they
         | didn't include their magnetization measurements, even if it
         | didn't confirm superconductivity. The first conclusive paper
         | will have to demonstrate a superconducting transition in both
         | electrical resistivity and magnetization.
        
       | moralestapia wrote:
       | I really really wanted this to be true just so we can all take a
       | look at how much wrong some things are in academia and science
       | nowadays.
       | 
       | Plenty of "knowledgeable" people and research groups put out a
       | lot of discrediting (and actually ignorant) statements about
       | this, a lot of them with a dash of xenophobia in the mix.
       | 
       | Congrats to the people that actually push science forwards!
       | 
       | Haters gonna hate but no one will remmeber them, ever.
        
       | superposeur wrote:
       | Question for the cognoscenti: supposing that LK-99 superconducts
       | with T_c = 110 K, how significant a discovery would this be?
       | I.e., does it establish a brand new class of high-T
       | superconductors, or is it merely one unremarkable member of a
       | known class? Further, does it offer advantages over other high-T
       | superconductors such as ease of fabrication or cost?
        
         | scheme271 wrote:
         | To add to the other reply, it'd be a new class especially since
         | it would be at standard pressure. I think the current highest
         | Tc SC at standard pressure is at much lower temperatures.
         | Frankly, there's probably a lot that you can do with a
         | superconductor that you can cool with liquid nitrogen even if
         | it can't carry much current or handle high magnetic fields.
         | Moving from liquid helium cooling to liquid nitrogen alone
         | significantly reduces the cost and complexity of your cooling
         | system.
        
           | AnnikaL wrote:
           | Don't YBCO superconductors already work at liquid nitrogen
           | temperatures?
        
         | cthalupa wrote:
         | It's a brand new class.
         | 
         | The material cost is lower than most superconductors - it's
         | lead and copper - but no one has any idea on fabrication, yield
         | size, etc., now, so no good answers there.
        
           | superposeur wrote:
           | Thanks.
        
       | soligern wrote:
       | In the observations, this sample they tested did not exhibit the
       | Meissner effect at room temperature. Which means it's not the
       | same thing the original team discovered?
        
         | Levitating wrote:
         | They stated no "obvious" Meissner effect was detected.
         | 
         | Possibly because the sample includes too many impurities.
        
       | downWidOutaFite wrote:
       | A 110k superconductor would not be revolutionary since we already
       | have some in that vicinity.
        
         | belltaco wrote:
         | First, at a minimum it validates that the researchers found a
         | novel rare superconductor at ambient pressure, and are not
         | frauds.
         | 
         | Second, the new mechanism of superconductivity may lead
         | scientists to explore other materials with similar properties
         | that may work better.
         | 
         | Third, the synthesis may not be completely spot on yet. It has
         | been just 4 days of attempting replication, and this result is
         | pretty good in that context.
        
         | slavetologic wrote:
         | That's what I'm not understanding about this frenzy. Seems like
         | this already kind of exists?
        
           | internetter wrote:
           | The original report is billed as a "room temperature
           | superconductor" (iirc up to 28c). If it is indeed a
           | superconductor at room temperature, it would be the first of
           | it's kind and enable functional usages for superconductors
           | previously impossible.
        
             | dgoldstein0 wrote:
             | The original claim was Tc of 127c - above the boiling point
             | of water.
             | 
             | Plenty of reason to doubt it though. Of course I'm hoping
             | it's real.
        
               | internetter wrote:
               | Wow, that's crazy! I guess I missed the 1 in front. I'd
               | say the more I read the more optimistic I become. Fingers
               | crossed!!
        
         | kamranjon wrote:
         | Is my understanding correct that 100k at ambient pressure is
         | pretty special on its own?
        
           | downWidOutaFite wrote:
           | YBCO and BSCCO are superconductors around 100K at ambient
           | pressure. Unfortunately their brittleness limits their
           | practical use. Maybe LK-99 will have better mechanical
           | properties.
        
             | adrian_b wrote:
             | Unfortunately no.
             | 
             | In this paper it is mentioned that the fact that the
             | material is very fragile made it difficult to obtain pieces
             | of a consistent size and form for measurements.
             | 
             | Moreover, from the results of the theoretical papers it is
             | suggested that perhaps this material would work best as a
             | monocrystal, with anisotropic conduction properties.
             | 
             | That could still have very important applications, but not
             | for making cables or coils.
        
         | modeless wrote:
         | An entirely new category of superconductor could well be
         | revolutionary even at this temperature, for several reasons. It
         | could be the first one of a family with variants that go up to
         | room temperature. It could be cheaper to produce or have other
         | desirable properties for commercial applications. And it could
         | lead to advances in theory that would allow prediction of other
         | unknown superconductors.
        
         | brianpan wrote:
         | This is not about 110K, this is about trying to verify the
         | results related to LK-99.
         | 
         | The LK-99 that is room temp superconductive seems quite
         | difficult to produce at this early stage. But these researchers
         | were able to produce their not-as-good version of LK-99 and at
         | least verify very close to superconductivity at 110K. This
         | makes the LK-99 room temp superconductivity claims that much
         | more plausible.
        
           | TillE wrote:
           | Exactly. There are too many unknowns to draw any kind of real
           | conclusions, but everything so far still supports a position
           | of cautious optimism.
           | 
           | What we know is that LK-99 looks pretty interesting. Is it a
           | room-temperature superconductor? Maybe!
        
       | ur-whale wrote:
       | And now for a slightly different take on the much-discussed room
       | temp. superconductors:
       | 
       | on the off chance that this LK-99 stuff is actually going to be a
       | thing, how should that influence my investment portfolio over the
       | course of the next five years?
       | 
       | Should I buy lead mining stock ?(joke, obviously, but you get the
       | point).
        
         | dougmwne wrote:
         | It would bias our energy markets towards electric and away from
         | fossil fuels. But due to climate change, there's already a lot
         | of pressure to go in this direction.
        
       | Waterluvian wrote:
       | I don't understand the physics, but it _feels_ like a truly zero
       | resistance conductor would violate some law of thermodynamics or
       | something.
       | 
       | Is a superconductor truly zero impedence or just very very very
       | low? Because I'm seeing a lot of these graphs with something
       | like: "0.00001ohm" as the y-axis floor.
        
         | klyrs wrote:
         | Key point, resistance is the real part of impedance. The
         | imaginary part, or inductance and capacitance, are not zero in
         | a superconductor.
        
         | thehappypm wrote:
         | Ask yourself this question: Why does resistance occur at all?
         | Why is it that electrons moving through a material cause them
         | to heat up? What is actually happening to cause that?
         | 
         | At micro levels, like molecules bouncing around in a gas,
         | collisions are lossless. What makes electrons moving through
         | materials different?
        
         | daxfohl wrote:
         | Similar to how a magnet works. A magnet can hold something
         | forever, so seems like a violation of thermodynamics. But
         | "holding" isn't work, it's just force. (Which is still kinda
         | spooky, admittedly) Similarly, conducting itself isn't work,
         | it's just conduction.
        
           | huthuthike wrote:
           | It's a lot less spooky when you consider that your desk can
           | hold your coffee mug forever. It's exerting force on the mug,
           | but not doing any work.
        
             | flavius29663 wrote:
             | even more so as the mug literally levitates above the desk,
             | the atoms of the mug are not really touching the atoms of
             | the desk.
        
               | snowwrestler wrote:
               | The atoms do touch, by interacting electrically--which is
               | the physical definition of how anything touches anything.
        
         | yongjik wrote:
         | Not an answer, but if you think superconductor is weird, look
         | up superfluid, now that's going to make your head spin.
        
           | 55555 wrote:
           | Thanks for the interesting new thing. If they suffer no loss
           | in kinetic energy and a wave can move forever, could we use a
           | circular pool of superfluid as an an energy storage
           | mechanism?
        
             | n2d4 wrote:
             | Maybe, but it's probably easier to just use a
             | superconductor for the same: https://en.wikipedia.org/wiki/
             | Superconducting_magnetic_energ...
        
             | yongjik wrote:
             | Well, the whole thing must be at liquid helium temperature,
             | so probably not practical ...
        
           | alex_suzuki wrote:
           | Superfluids have been around for ages - we call them beers.
        
           | LightMachine wrote:
           | why there are no good videos of superfluids in action in the
           | whole internet?
        
             | fragmede wrote:
             | I thought https://youtu.be/2Z6UJbwxBZI was pretty good,
             | even if it's low res from being a bit dated.
        
               | 55555 wrote:
               | there's not a single high-quality video anywhere. Science
               | YouTubers need to get on this
        
         | marcosdumay wrote:
         | The electrons are always moving in some direction. What a
         | superconductor does is "just" making an electron pull others
         | with it, making a cascade effect that biases the movement
         | permanently.
         | 
         | There is no work or state change, so no reason at all to
         | conflict with the 2nd law of thermodynamics.
        
         | [deleted]
        
         | _ph_ wrote:
         | Yes, as others already said, superconductors are zero
         | resistance. Which is easy to check if you have enough of the
         | substance to run meaninful currents through it. There might be
         | miniscule amounts of resistance for contacting and impurities,
         | but the resistance doesn't grow e.g. with wire length.
         | 
         | So how is this possible? The explanation is acutally reasonably
         | easy, but requires the strangeness of quantum dynamics. One
         | basic principle of quantum dynamics is, that at least most
         | things are quantisized. Especially energy of a state comes in
         | discrete amounts. That is the reason we have orbitals of
         | electrons in atoms. They can only take very specific values,
         | which creates these separate orbitals. There is no in between
         | state, they have always to absorb or emit exactly the amount of
         | energy which is the difference between orbitals when moving
         | between them. Which is a very easy effect to literally see:
         | take glowing phosphors as you find them on your watch etc.
         | These are transitions bound to a specific photon energy. With
         | red light, you cannot "charge" them, as red photons have to
         | little energy, and you can only absorb single photons. Any
         | green or blue light would work though. And whatever light you
         | used to "charge" them, they always glow in the precise same
         | color, coming from their destinct energy state.
         | 
         | The resistance an electron encounters while moving through a
         | conductor is also quantisized. In superconductors we have a
         | situation like trying to charge a watch dial with red light:
         | the amounts of energy an electron could release cannot be
         | absorbed by the material. And an interaction would require
         | this. The consequence is: no interaction, no resistance.
         | 
         | The situation is like trying to buy a $1 bottle of water with a
         | $100 bill. That could turn out to be impossible, because no one
         | is willing to give you back $99, and you can of course not pay
         | $100 for the bottle. So even when having the money, you can't
         | buy the bottle.
         | 
         | This is, in a very naive way, the principle how
         | superconductivity and superfluidity work. The trick now is to
         | prepare the conditions which allow for superconductivity. One
         | way is to make things increadibly cold. All metals become
         | superconductive, if the temperature is close enough to 0. But
         | that is with single digit degrees or below, even fractions of a
         | Kelvin. Konsequently it was a huge sensation when the first
         | complex substance was presented which showed the effect at
         | larger temperatures. Since then the hunt is up to find better
         | substances.
        
           | Jyaif wrote:
           | Fascinating.
           | 
           | Let me get this straight: If you have a piece of phosphor,
           | you can't heat it up with red light, regardless of the amount
           | of red light you shine at it? If so, does the red light
           | bounce off? Go straight through?
        
             | _ph_ wrote:
             | Yes, it will of course absorb or reflect the red light like
             | any stone would, but to "charge" its luminiszence you need
             | at least green light - blue works great. That is, why you
             | never could charge your watch dial with incandescent light,
             | but any white LED will work great because their light
             | usually contains a lot of blue light. Fun fact: though it
             | is calles "phosphorescence" all those colors don't contain
             | any Phosphor, that Phosphor isn't phosphorescent :p An
             | error in early naming.
        
         | ramraj07 wrote:
         | MRI machines work using superconducting magnets as does the
         | LHC. So you better believe it buddy.
        
           | Waterluvian wrote:
           | Why do MRIs need zero resistance vs incredibly low
           | resistance?
        
             | scythe wrote:
             | The current is ridiculously large and would lead to an
             | unacceptably high power consumption and thermal expansion
             | with the resistivity of even a good metal (copper).
        
             | thelazyone wrote:
             | I think it's a fair question. I guess the answer is
             | "because we have superconductors, and no material with
             | 'very small resistance' instead".
             | 
             | Also note that while there is zero resistance you still
             | have parasitic currents and general interaction with the
             | rest of the environment. So no perpetual motion for us
             | today!
        
               | jacquesm wrote:
               | Even a 'very small resistance' would likely be
               | prohibitive. Pure silver for instance is an excellent
               | conductor, but when you're talking about the last little
               | bits it's _orders of magnitude_ difference between that
               | and a superconductor, and those orders of magnitude
               | difference in resistance translate into orders of
               | magnitude more current. So even a small resistance would
               | cause your MRI machine to have a resolution so low as to
               | be unusable.
        
               | jychang wrote:
               | Actually, there are infinite orders of magnitude between
               | the resistance of silver and that of a superconductor.
        
               | [deleted]
        
               | obrix wrote:
               | MR imaging is possible with permanent magnets and
               | resistive (copper wire wound) magnets at low field
               | strengths, below 0.35T or so. Above that the heating of
               | the magnet windings becomes excessive and it would be
               | very difficult to maintain a stable enough field
               | strength.
               | 
               | Superconducting magnets are very nice as long as there is
               | no quenching. The material used for conductors must be
               | mechanically stable and perform consistently from one
               | production batch to another. One reason why current high
               | tc superconductors are not popular...
        
               | stcredzero wrote:
               | _The material used for conductors must be mechanically
               | stable and perform consistently from one production batch
               | to another. One reason why current high tc
               | superconductors are not popular_
               | 
               | I was going to ask: Why don't we use the current high
               | temperature superconductors, and start building grid
               | interconnects? I guess part of the answer lies in the
               | cost that would be incurred because of the mechanical
               | properties of the existing superconductors.
        
               | mrguyorama wrote:
               | The current best "High temperature", standard pressure
               | superconductor only works at -150ish degrees Celsius.
               | That's not as bad as cryogenic superconductors, but it is
               | still a blocker for large scale use.
        
             | wbl wrote:
             | The more you crank up the field and gradients the better
             | resolution you can get. Being able to take MRI of a beating
             | heart depends on that sort of thing.
        
             | userbinator wrote:
             | To create very, _very_ strong magnetic fields.
        
             | crote wrote:
             | They don't!
             | 
             | MRI scanners work just fine with regular electromagnets, or
             | even plain old normal magnets. However, work better with
             | stronger magnetic fields. In practice normal magnets end up
             | being extremely large and heavy, and electromagnets end up
             | using massive amounts of power. Both options are also
             | limited in their field strength because getting enough
             | _stuff_ close together is tricky.
             | 
             | A superconducting magnet is an electromagnet which is way
             | smaller and uses orders of magnitude less power. For
             | extremely high field strength MRIs they are the only viable
             | option, and for regular MRIs they are often the best
             | option.
        
             | jacquesm wrote:
             | Because the resistance is the limiting factor in how strong
             | a magnetic field can be made in a given volume using the
             | conducting material.
             | 
             | Copper across an area of 1 cm ^2 does about 300A, compare
             | with https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8047038/
             | for what some superconductors can do.
        
               | yreg wrote:
               | That's not an answer to that question.
        
               | robotresearcher wrote:
               | Link says 90 MA per cm^2, or 30,000X more than copper.
               | 
               | Gulp!
        
               | patrec wrote:
               | I think you are missing a zero.
        
               | robotresearcher wrote:
               | You are right!
               | 
               | 300,000X more than copper.
               | 
               | Typo converting from brain to screen. I should have used
               | exponential notation and the mistake would have been more
               | obvious.
        
         | distortionfield wrote:
         | It doesn't though, that's what's so tantalizing about it. It's
         | counterintuitive but as I understand it, the current best
         | theory of superconductor behavior properly conserves mass and
         | energy and the math says a room temperature one should be
         | perfectly possible. It's just not been found. And yes, it's
         | truly zero resistance as far as we understand the concept of
         | "resistance".
        
       | wwarner wrote:
       | Here's Brian Keating interviewing Jorge Hirsch from UC San Diego
       | and Inna Vishik of UC Davis [0]. Prof Hirsch was/is a leading
       | critic of the U Rochester papers, but thinks that LK-99 could
       | work.
       | 
       | [0] https://www.youtube.com/watch?v=qQnDatnAWP4
        
       | mrandish wrote:
       | For comparison, per this Wikipedia page
       | (https://en.wikipedia.org/wiki/High-temperature_superconducti...)
       | currently, the highest temperature, ambient pressure
       | superconductor is around 138 K (-135 degC).
       | 
       | I'm no expert but based on my limited understanding, this result
       | (if confirmed) while far from room temperature would still make
       | LK99 a pretty interesting discovery in the SC world. And once a
       | new SC like this is validated there are often methods discovered
       | to improve the temperature or optimize other traits.
       | 
       | To me, the positive news here is that (if confirmed), at least
       | LK99 isn't "nothing". Together with the recently released
       | simulation studies indicating LK99 may have interesting SC-like
       | properties, this causes me to increase my personal Bayesian SWAG
       | estimate on LK99 (or a related descendant) eventually being a
       | meaningful step toward room temp superconductors.
        
         | gabesullice wrote:
         | Agreed. Looking at the timeline on the Wikipedia page, a new
         | 100K ambient pressure SC material is nothing to scoff at.
         | 
         | It means LK99 is about as good as the other materials, at
         | minimum. _However_ , its chemical composition is different than
         | any of the other materials on the chart (i.e. it is lead
         | based). That probably means there's lots to learn and new
         | phenomena to be understood and optimized.
         | 
         | Furthermore, if this lab could achieve these results in a
         | matter of weeks, perhaps labs with more exotic equipment and
         | dedication will be able to get better results, raising the bar
         | even higher.
        
           | dr_zoidberg wrote:
           | > It means LK99 is about as good as the other materials, at
           | minimum. However, its chemical composition is different than
           | any of the other materials on the chart (i.e. it is lead
           | based)
           | 
           | While what you say is correct, let's not forget that lead
           | _is_ an elemental superconductor. With a Tc of 7K, it's only
           | bested by niobium (9K) and diamond (11K) as an elemental
           | superconductor.
           | 
           | Yes, cuprates and ceramics were ruling high-temperature SC so
           | far, but it's not like lead was entirely unexpected in the
           | superconducting world.
        
           | jjallen wrote:
           | Exactly. These are literally the first attempts to replicate
           | a poorly explained production process. Things are only going
           | to get better over time as the materials increase in purity.
           | These are other labs seeking publicity partly.
           | 
           | I for one think that this will turn out to be a major
           | breakthrough based on the meta facts (decades of development
           | for one) and not the actual science.
        
         | [deleted]
        
         | distortionfield wrote:
         | The doping agents used in synthesis seem like interesting
         | pathways towards finding something more stable and reproducible
         | in their cook
        
         | rwmj wrote:
         | It's always interesting to discover a new class of materials
         | that make high temperature superconductors even if they haven't
         | discovered a room temp one.
        
       | jcranmer wrote:
       | Looking at the key temperature-resistivity graphs, this feels
       | like the data doesn't support the conclusion that there's a
       | superconductor here. The temperature-resistivity graphs of
       | superconductors I've seen all have a fairly steep cutoff--a
       | sharp, vertical line at critical temperature. The log-scale here
       | complicates my intuition, but what I see is a gradual transition
       | into noise range. Also, the graphs I've seen have also
       | demonstrated that the critical temperature varies with applied
       | magnetic field. Here... there's no apparent variation in apparent
       | critical temperature.
       | 
       | I'm sorry, but this result just feels to me like people are
       | assuming that the material must be a superconductor and are
       | analyzing all the data under that assumption rather than asking
       | the question "is this a superconductor?"
        
         | Klaus23 wrote:
         | The gradual drop could be the result of a mixed sample where
         | different parts of the material show superconductivity at
         | different temperatures. As more of the sample becomes
         | superconducting, the resistance will gradually decrease until a
         | superconducting path is created between the probes and the
         | resistance reaches zero.
        
         | evancox100 wrote:
         | Not a superconductor expert, but resistance exponentially
         | decreasing with temperature is not a normal phenomenon in most
         | cases!
        
           | bandrami wrote:
           | Most semiconductors have a thermal regime where that happens,
           | it's just a relatively small regime, I thought?
        
             | [deleted]
        
             | adrian_b wrote:
             | Here the resistance decreases in the opposite direction, so
             | it cannot be explained by changes in the concentration of
             | free carriers, like in semiconductors.
             | 
             | In metals, the concentration of free carriers is constant
             | and the resistance decreases towards lower temperatures
             | because the mobility of the free carriers increases, i.e.
             | there is less friction between them and the crystal
             | lattice, because the vibrations of the latter have a
             | smaller amplitude. However this does not lead to any
             | exponential decrease of the resistance.
             | 
             | The weird current dependence on voltage and temperature
             | that can be seen here is most likely caused by an
             | inhomogeneous sample that is composed of many small domains
             | with different electrical properties.
             | 
             | Moreover, the material may be anisotropic, so extra
             | variability is added by the random orientations of the
             | microcrystals that compose the ceramic sample.
        
               | bandrami wrote:
               | Thanks; I managed to read GP comment backwards somehow.
        
             | evancox100 wrote:
             | I should probably be fired for my prior answer because
             | things like pn-junction diodes can definitely have an
             | exponential-like dependence on temperature.
             | 
             | In my head I was thinking of pure elements, like bulk
             | metals. But there definitely could be more interesting
             | things going on in the sample, like diode formation
             | (internally or at the contacts) or weird doping profiles.
             | That may be part of why it's hard to measure the
             | properties!
        
               | adrian_b wrote:
               | Intrinsic semiconductors or the semiconductors that are
               | lightly doped with impurities have temperature ranges
               | where the concentration of the free charge carriers
               | increases exponentially with increasing temperature, like
               | in the NTC (negative temperature coefficient)
               | thermistors.
               | 
               | This causes a decrease in resistance towards higher
               | temperatures, so it has nothing to do with any
               | explanation for a decrease in resistance towards lower
               | temperatures.
               | 
               | The diodes have increasing inverse currents towards
               | higher temperatures, which also has nothing to do with
               | any explanation for increasing currents towards lower
               | temperatures.
        
         | adamsmith143 wrote:
         | The proposed mechanism for superconductivity in lk-99 is pretty
         | different so that may be confounding your interpretation of
         | those graphs.
        
         | gilbetron wrote:
         | On log-scale, a line will be an exponential in a linear curve.
         | Here we have a curve on log-scale arcing down, which means it
         | drops faster than exponential, which is, more or less, a cliff-
         | like dropoff.
        
         | 46Bit wrote:
         | https://nitter.net/condensed_the/status/1686895266329174016
         | claims a linear representation of the same data. Still no
         | convincing discontinuity visible.
        
           | IsTom wrote:
           | Makes the dip around 250K even more visible.
        
             | pja wrote:
             | That is a fantastically weird temp / resistance chart.
             | 
             | Would semi-conductor like properties result in something
             | like this - thermal noise pushing electrons into the band
             | gap?
        
         | segfaultbuserr wrote:
         | > _The log-scale here complicates my intuition_
         | 
         | Logarithmic plots are a device of the devil. - Charles Richter
        
       | keyle wrote:
       | > In conclusion, we successfully synthesized the compound
       | Pb10-xCux(PO4)6O, and observed the zero resistance above 100 K.
       | However, the Meissner effect has not been observed yet in our
       | samples, which suggests that the superconducting volume is
       | relatively low.
       | 
       | In conclusion, ... nothing?
        
         | DistractionRect wrote:
         | It's likely that impurities in the bulk of the sample are why
         | we aren't seeing the Meissner effect. Seeing super conductivity
         | though is extremely promising.
         | 
         | We've seen a sample be super conductors at 110k ambient
         | pressure, diamagnetism, and (unconfirmed) flux pinning. So it's
         | likely there's something here, but right now the main hurdle is
         | synthesis. It's difficult to make and there's no clear path to
         | consistency, purity or scale.
        
         | ayakang31415 wrote:
         | It's definitely something, rather big something, to observe
         | zero resistance above 100k
        
           | awwkaw wrote:
           | Not compared to the claim of zero restance up to 400 K.
           | 
           | But with how difficult the samples production seems to be,
           | maybe we will get 400 K superconductors still
        
       | userbinator wrote:
       | I completely ignored the authors (as I usually do) and started
       | reading it, noticed the slightly odd phrasing, and then chuckled
       | at "mad great efforts" and then "a very excited news" a short
       | while later before looking at the authors and realising the
       | country of origin.
        
       | elromulous wrote:
       | ELI5, if these folks confirmed zero resistance at room temp and
       | atmospheric pressure, isn't that confirmation of the original
       | paper?
       | 
       | Edit: I read 100 K as 100degc. Mea culpa.
        
         | mcqueenjordan wrote:
         | 100 degrees kelvin is about 338 degrees Fahrenheit below room
         | temperature.
        
           | elromulous wrote:
           | Duh. Thanks. I think my brain must have transposed that K to
           | C.
        
             | mcqueenjordan wrote:
             | I also did that the first time when reading the abstract.
             | Very relatable. "It's on the front page of HN, so it must
             | be a remarkable result," my subconscious seemed to assume
             | on my behalf. ;)
             | 
             | Fool me once...
        
           | matsemann wrote:
           | Thanks for making it even more confusing by introducing
           | Fahrenheit, haha. ;)
        
       | JoeAltmaier wrote:
       | Reliable production of the material is an engineering problem. If
       | it can just be shown to work once, then the goal will be to mass-
       | produce it in useful forms and structures.
       | 
       | Replication has been partially successful, exhibiting remarkable
       | new results that are already worth celebrating.
        
       | boringuser2 wrote:
       | The most compelling evidence offered thus far is from actual
       | scientists that have reviewed the LK-99 paper and determined the
       | scientists involved aren't very good at science.
        
       | hamilyon2 wrote:
       | Why is western mass media silent? They always pick up emerging
       | stories like that, but not in this case for some reason
        
         | crote wrote:
         | Western media isn't silent. It has been showing up in the
         | science section of mainstream media for a few days now, with a
         | healthy dose of skepticism around it.
         | 
         | It's in the New York Post, on CNET, on CNBC, the Washington
         | Post, Wired, New Scientist, Popular Mechanics, and plenty more.
         | Just because CNN isn't covering it 24/7 doesn't mean the
         | western mass media is "silent".
        
           | hamilyon2 wrote:
           | Good to know. So it means that the particular subset of media
           | I am paying attention is silent. Thank you for the correction
        
       | tomohelix wrote:
       | Summary of events so far:
       | 
       | The claim: Room temp (~300K) superconductor exists and we got it!
       | 
       | The replication attempts: The production method is so poorly
       | documented only a fraction of the samples being made shows any
       | interesting properties. And among those interesting ones, results
       | varies. Very few, if any, attempt actually completely shows the
       | entire spectrum of properties and behaviors of a true
       | superconductor at room temperature yet. But those kinds of
       | experiments take time so it isn't an indicator of problem.
       | 
       | My take: It is probably something interesting but not well
       | understood. Best case scenario, the original sample in the Korean
       | lab probably won the synthesis lottery and is actually a true
       | room temp superconductor. Worst case scenario, we got another
       | class of high temp (warmer than liquid nitrogen but cold enough
       | that applications are limited) superconductor but nothing
       | revolutionary since at this point, it is pretty conclusive that
       | there is something interesting with LK-99.
        
         | adrian_b wrote:
         | While the production method of the original Korean authors is
         | poorly documented, the synthesis method used for this paper is
         | described in a very detailed way, also mentioning a few
         | alternative steps that have been tried, but which caused
         | failures in obtaining the desired structure.
         | 
         | While their synthesis method works very well for something
         | improvised in a couple of days, it requires significant
         | improvements, because the samples are very inhomogeneous, which
         | greatly complicates the measurements and the interpretation of
         | the results.
         | 
         | I believe that the properties of this material will not be
         | completely elucidated until someone grows a monocrystal of it,
         | but developing a process for this might take months, if not
         | years.
        
         | jjallen wrote:
         | What is this supposed to be a summary of? The temperature at
         | which this team observed zero resistivity was much much colder
         | than room temp.
        
         | s0rce wrote:
         | Most papers are so bad its nearly impossible to replicate the
         | synthesis.
        
           | adrian_b wrote:
           | Not this one, which has a very detailed description of the
           | synthesis, including what has worked and what has failed.
        
         | fnordpiglet wrote:
         | I'd note they claimed to try the synthesis over 1000 times to
         | arrive at their best sample. They admit to not being physicists
         | and being more experimental chemists. If there is anything
         | here, which at minimum seems they've found something
         | interesting. The theoretic research published recently
         | supporting their claims coupled with the discussion that the
         | apparently superconducting material is less likely to form it's
         | probably (IMO, IANAP) a process that requires substantial
         | refinement but holds a claimed experimental and theoretically
         | demonstrated potential to be a room temperature normal pressure
         | superconductor as claimed. There seems to be a lot of "their
         | work is sloppy" and "their method isn't refined" as a proof of
         | a negative, but it's just proof that science is done in many
         | ways by many techniques and no one is sufficient, but everyone
         | is necessary.
        
         | [deleted]
        
         | jcranmer wrote:
         | > Worst case scenario, we got another class of high temp
         | (warmer than liquid nitrogen but cold enough that applications
         | are limited) superconductor but nothing revolutionary since at
         | this point, it is pretty conclusive that there is something
         | interesting with LK-99.
         | 
         | I don't think that's the worst case scenario. The worst case
         | scenario is that there is actually nothing interesting with
         | LK-99, and everything we've seen that suggests otherwise is
         | experimenter bias heaped on top of experimental error. I'm
         | actually surprised by the sheer lack of people commenting in
         | the more-or-less-perma-LK-99 threads who show skepticism of the
         | results.
        
           | blueprint wrote:
           | > The worst case scenario is that there is actually nothing
           | interesting with LK-99, and everything we've seen that
           | suggests otherwise is experimenter bias heaped on top of
           | experimental error.
           | 
           | well while we're one-upping each other I'm pretty sure the
           | worst case scenario is some lk99 synthesizer actually creates
           | a black hole which gobbles up the planet.
        
             | anonuser123456 wrote:
             | An lk99 synthesizer creating a false vacuum decay would be
             | worse.
        
               | blueprint wrote:
               | true! or an lk99 synthesizer accidentally generating the
               | waveform of Never Gonna Give You Up
        
             | bluGill wrote:
             | sure, but that is unlikely. If massive black holes opened
             | up in labs then it would have already done so. Probably by
             | chance in the dinosaur age.
        
             | nonethewiser wrote:
             | What if thats where all black holes come from and thats why
             | we haven't found any aliens? Just a misfortune reality that
             | "accidental blackhole" is lower on the tech tree than fast
             | space travel.
        
               | [deleted]
        
           | DrBazza wrote:
           | > I'm actually surprised by the sheer lack of people
           | commenting in the more-or-less-perma-LK-99 threads who show
           | skepticism of the results.
           | 
           | HN is supposed to have a high signal-to-noise for comments.
           | I'm skeptical about this. I think it's the modern Pons +
           | Fleishmann, but I won't post that on every thread because it
           | contributes nothing. There's more insightful, and interesting
           | comments about chemistry than anything I can write that would
           | add to the discussion.
        
           | tomohelix wrote:
           | Personally, I think we are past the point of this being
           | nothing. There have been multiple confirmations of at least
           | something unexplained going on. Maybe all of them are wrong
           | but honestly, that is more of an extraordinary claim than
           | saying this is something interesting, just not a full on room
           | temp superconductor.
        
             | Analemma_ wrote:
             | I understand why a lot of people think this, but I don't
             | think we can say that with confidence yet. Cold fusion
             | "replicated successfully" multiple times in the 80s too.
        
               | dmarchand90 wrote:
               | The big difference is that standard theoretical
               | techniques have indicated the compound to be promising
               | from an electronic structure point of view and confirmed
               | that it would be tricky to synthesize just right.
               | 
               | Cold fusion always was dependent on new physics to be
               | discovered
        
               | FrustratedMonky wrote:
               | Wasn't the problem with Cold Fusion that it did NOT
               | replicate, and thus got sullied with a bad reputation, so
               | nobody wanted to touch it.
               | 
               | Then decades later, it's still kind of open question.
               | Aren't there some studies still going on, more on the
               | down-low since it has such a bad reputation. Kind of like
               | the super-conductor, have to keep it quiet and make
               | really sure before publishing.
               | 
               | Sabine did video on Cold Fusion that was pretty
               | interesting. https://www.youtube.com/watch?v=ZbzcYQVrTxQ
        
               | rrssh wrote:
               | There were positive and negative results, just like in
               | this case.
        
               | marcosdumay wrote:
               | Some stuff replicated. It was clearly not cold fusion.
               | 
               | Some people made a career studying the kinds of
               | sonoluminescence needed to explain what that experiment
               | saw. (And AFAIK, nobody found a use for the theory yet.)
        
               | gus_massa wrote:
               | In the cold fusion experiments, they were measuring an
               | exess of heat. That's very difficult to measure, and some
               | noise or experimental error can confuse the people.
               | 
               | No one measured a huge flow of neutrons, that were
               | expected to be generated by the fusion and are more easy
               | to distingish from noise.
        
               | nwiswell wrote:
               | There are now several authentic videos of bits of rock
               | (lead apatite) appearing to do things around magnets that
               | they have no business doing.
               | 
               | Maybe there's a lot of smoke and no fire, but there's
               | videographic evidence of _something_ weird going on.
        
               | wahern wrote:
               | Unfortunately, we live in the age of TikTok. Videos on
               | their own bring no more credibility than written text;
               | they no longer evince a substantively greater investment
               | of resources. I'm more inclined toward the cheerleading
               | section of the LK-99 audience, but watching the videos I
               | realized now is a perfect opportunity to apply
               | recalibrated B.S. detectors.
        
               | drexlspivey wrote:
               | This doesnt pass the smell test. Why would multiple
               | independent labs fake their videos? What's the conspiracy
               | here? There is no upside, we will know in a couple of
               | weeks if it's real or not.
        
               | ekianjo wrote:
               | > Why would multiple independent labs fake their videos
               | 
               | Why would different newspapers spread hoaxes? Yet it
               | happens...
        
               | Larrikin wrote:
               | Which hoax specifically was completely fabricated by the
               | newspapers and spread by multiple newspapers? State run
               | media obviously doesn't count.
               | 
               | Poor source checking and then issuing a retraction is not
               | the same as a conspiracy among the papers to make
               | something up completely.
        
               | ImPostingOnHN wrote:
               | why would you respond to the question with an unrelated
               | question instead of answering directly?
        
               | drexlspivey wrote:
               | newspapers get paid by the click
        
               | wahern wrote:
               | I didn't mean to insinuate that anybody faked anything.
               | Just that video evidence on its own isn't per se any more
               | credible than if they unambiguously made the same claim
               | in writing. The technology for making fake or misleading
               | videos is easy to come by, so why mentally lean on the
               | fact that they were videos at all? Our answers wrt
               | likelihood of truthfulness simply lie in provenance and
               | other indicia of credibility that would be shared with
               | claims in any other trivially falsified medium, like
               | writing. Why, indeed, would multiple seemingly non-
               | cooperating supposed researchers make the set of claims
               | that have been made?
               | 
               | I don't think anything was faked, nor did I think
               | anything was faked before videos began appearing. But
               | that's precisely why this is an opportune time to
               | exercise recalibrated judgment in not allowing the
               | videographic character to inflate my cautious enthusiasm.
        
               | imtringued wrote:
               | If it takes X weeks to do research and someone publishes
               | results before that time, then the conclusion that the
               | results are suspect is warranted and is in no way a
               | conspiracy theory.
        
               | ClumsyPilot wrote:
               | Thats because Cold Fusion does work, its just useless. It
               | loses energy.
               | 
               | You need Muons, a negatively charged particle that is 200
               | times heavier than an electron. They replace electron in
               | the atom. Two Muon-replaced atoms of hydrogen can fuse at
               | room temperature.
               | 
               | The problem is that muons a very expensive to produce and
               | decay quickly. So you spend more energy producing muons
               | than you get from fusion.
               | 
               | https://en.m.wikipedia.org/wiki/Muon-catalyzed_fusion
        
             | Affric wrote:
             | Reading this paper they're pretty restrained. They got zero
             | resistance but didn't get everything they were looking for.
             | 
             | This material is fascinating and I love the interest and
             | good debate it's generating.
             | 
             | Sometimes it feels like we missed so many golden ages but
             | we might still get to experience something world changing
             | before our eyes and understand what it means.
             | 
             | Real technological progress and societal improvement breed
             | optimism. This could be the start of something big. Even if
             | it isn't it reminds us why we are still searching for
             | theorised technologies.
        
             | marcosdumay wrote:
             | It's not that extraordinary.
             | 
             | When people rush to replicate an experiment, everybody with
             | a positive result has something to publish very quickly,
             | and everybody with a negative result need a lot more time
             | to be certain of it.
             | 
             | The kinds of results we are seeing are very hard to get by
             | chance or due to bad experimental setup. But as a rule, we
             | can't really differentiate a real thing from random noise
             | in as little time as have passed.
        
               | bluGill wrote:
               | But that people have a positive result at all to publish
               | is extraordinary. If this isn't a super conductor at this
               | point that is probably even bigger than a superconductor
               | - it means there is other physics we are not aware of to
               | investigate.
               | 
               | At this point I've changed to this is probably true, but
               | I don't know how big it is. (if it is true but impossible
               | to produce at industrial scale it is not revolutionary)
        
               | jseip wrote:
               | "It's not that extraordinary."
               | 
               | How is that possibly true? LK-99 is already amongst the
               | highest-temperature superconductors ever found (with that
               | claim substantiated by at least two independent research
               | teams as of this moment).
        
               | whimsicalism wrote:
               | I don't know if you work in this field, but you are
               | putting way too much faith in what has been reported so
               | far
               | 
               | People are way, way overconfident. Most people in the
               | field would not be willing to put it at >50% odds at this
               | point.
        
               | eric_cc wrote:
               | > Most people in the field would not be willing to put it
               | at >50% odds at this point.
               | 
               | Do you have a source for this claim? It sounds like you
               | just made it up.
        
               | scarmig wrote:
               | There's not going to be a poll on it or anything.
               | 
               | But, for what it's worth, as both an LK-99 optimist and
               | as someone who has worked in the field and who still
               | talks to people in it, most people in it seem to put the
               | chances well below 50%.
        
               | whimsicalism wrote:
               | Of course not, there hasn't been some survey of materials
               | scientists on LK-99. This is my impression given my
               | familiarity with the field
        
               | marcosdumay wrote:
               | If you push it, all the diamagnetism videos people
               | published about reproducing it could be created by some
               | weird and unlikely distribution of ferromagnetism on the
               | sample. Except for the one that nobody knows where it
               | comes from, that could easily be a fabrication.
               | 
               | That leaves the original, that is clearly diamagnetism,
               | but still could be misleading in many ways.
               | 
               | We don't know how many labs are working on replicating
               | this. So we have no idea how unlikely mistakes we should
               | expect to see.
        
               | singularity2001 wrote:
               | So having a very strong diamagnet isn't interesting or is
               | there still reason to even doubt that part?
               | 
               | Only one of the four labs that completed replication has
               | claimed to have found diamagnetism, but how could that
               | video be explained otherwise?
        
           | SanderNL wrote:
           | It's good to keep an open mind both ways, but "skepticism"
           | without either interesting or convincing arguments is IMO
           | just as useless.
           | 
           | We all know there is a good chance it turns out to be a dud.
           | We all know cold fusion/emdrive/superluminal experiments
           | turned out to be duds. We all _know_ this.
           | 
           | I wonder what news do "skeptics" have to bring to the table.
           | Nothing a skeptic has to say changes anything. We are all -
           | except for the handful of actual experts here - amateurs at
           | best, but probably ignorant peasants. Just about anything we
           | have to say about it is just noise. I'd favor the positive
           | noise, but that's just me.
           | 
           | Imagine being at a football game: "This game could easily be
           | lost! Ah, see, another pass failed. Don't get your hopes up!
           | Please don't cheer, please wait until the very last moment
           | and then wait another hour to have administrative
           | confirmation. Then wait two weeks. Then you may cheer, but
           | only modestly."
        
             | matkoniecz wrote:
             | > It's good to keep an open mind both ways, but
             | "skepticism" without either interesting or convincing
             | arguments is IMO just as useless.
             | 
             | skepticism is an useful filter
             | 
             | > I wonder what news do "skeptics" have to bring to the
             | table.
             | 
             | reminder of "We all know there is a good chance it turns
             | out to be a dud. We all know cold
             | fusion/emdrive/superluminal experiments turned out to be
             | duds. We all know this."
             | 
             | not everyone knows this
        
               | HelloMcFly wrote:
               | > not everyone knows this
               | 
               | I actually think far more people know this than done; it
               | wouldn't surprise me if it truly is practically
               | "everyone" on Hacker News.
               | 
               | But what is the expectation here? Must every comment
               | thinking about the possibilities or being excited by
               | incremental evidence of support be prefaced with a note
               | of skepticism? Must we engage in such ritualistic
               | behavior in order to be seen as anything other than
               | hopeless scientific romantics? I must pour a bucket of
               | cold water on my own head before feeling even an ounce of
               | optimism? Optimism carries the possible - even likely -
               | cost of disappointment, and in the wrong company can
               | create the same in others. Pessimism is beneficial, but
               | it doesn't have to be worn on one's sleeve at all times
               | lest it sap joy and color from the world. This is a
               | community of enthusiasts, we can be enthusiastic without
               | also being hopeless idiots lurching from one false
               | discovery to the next.
        
               | SanderNL wrote:
               | Thank god for the skeptics. I might have gotten enthused
               | about something. Can you imagine the implications of
               | that? My god, please tell me someone is going to _stop_
               | me from being mildly entertained before it gets out of
               | hand.
               | 
               | Agents of reason, please enlighten us with your eternal
               | negativity so that we may perceive clearly the folly of
               | our excited ways.
        
             | [deleted]
        
           | stephencanon wrote:
           | Why would skeptics waste their time commenting on LK-99
           | threads? There are much better things to do.
        
             | bluGill wrote:
             | Because this is potentially a big deal. Skeptics who
             | understand they can be wrong will want to follow this, but
             | they don't want to get their hopes up.
        
           | highwaylights wrote:
           | Waiting to see either way just like everyone else, but..
           | 
           |  _> I 'm actually surprised by the sheer lack of people
           | commenting in the more-or-less-perma-LK-99 threads who show
           | skepticism of the results._
           | 
           | .. really? You're surprised by this?
        
           | Tade0 wrote:
           | > I'm actually surprised by the sheer lack of people
           | commenting in the more-or-less-perma-LK-99 threads who show
           | skepticism of the results.
           | 
           | You're not seeing them because every thread with a
           | significant percentage of sceptical voices trips the HN
           | flamewar detector, which goes off when there are more
           | comments than upvotes.
           | 
           | I've counted three threads where this happened. It's the
           | reason why the front page wasn't plastered with LK-99 news.
        
             | sparrowInHand wrote:
             | So, the accurate term for scientific debate on HN is a
             | cold-flamewar?
        
               | gus_massa wrote:
               | Sometimes the mods remove the automatic "flamewar"
               | penalty. Sometimes the add manual penalties.
               | 
               | My guess is that they are triying to keep in the front
               | page only the last 1 or 2 articles that has an important
               | update and enought discusion.
               | 
               | You can send them an email asking for clarification.
               | 
               | (I don't expect they have hard rules about this, only
               | some general principles and hopefuly good judgement
               | calls.)
        
           | doingtheiroming wrote:
           | There's plenty of skepticism. It's the zero-cost position
           | here. But there are good and bad skeptical positions. The
           | good one involves people attempting to replicate and
           | publishing results whether positive, negative or somewhere in
           | between. The bad one consists of sitting in forums and
           | threads being, "the voice of reason".
           | 
           | If there's a real problem, it's that we have still not made
           | publication of negative results sufficiently attractive.
           | That's still a problem throughout science and one we
           | desperately need to address since it is what would let us
           | think more clearly in situations like this.
        
             | api wrote:
             | > The bad one consists of sitting in forums and threads
             | being, "the voice of reason".
             | 
             | I refer to these folks as the "boring universe brigade."
             | The heuristic seems to be that if it's in any way exciting
             | it's probably bullshit. It's a blind overreaction to
             | memetically-optimized pseudoscience.
        
               | zeroonetwothree wrote:
               | Well, that position is right 99.9% of the time.
        
               | api wrote:
               | By that logic a rock is right 99.9% of the time. I just
               | asked one whether LK-99 will replicate and it said
               | nothing.
               | 
               | Reasonable skepticism is always warranted. I think this
               | thread is talking about reflexive cynicism and
               | instantaneous dismissal.
        
               | scarmig wrote:
               | pg: "Being too cynical will cause you to miss out on the
               | most important phase changes."
               | 
               | Defaulting to "no" might get you the right answer the
               | majority of the time, but it also makes you miss the
               | times that "yes" is correct. And correct things that are
               | a radical departure from the status quo are probably the
               | most important and useful to get right.
               | 
               | Skepticism is good (it's still ambiguous whether LK-99 is
               | anything at all), but pessimistic cynicism is not the
               | same thing.
        
               | abracadaniel wrote:
               | The brain loves an excuse to apply a noise cutting
               | heuristic. There was an article a while back about that
               | being a problem for general physicians, where the problem
               | is usually simple, but very very rarely something
               | serious. A doctor can appear good when they get it right
               | 99% of the time, but they might achieve that by
               | defaulting to "you're fine, here's some
               | (ibuprofen/antibiotic/antihistamine/etc)". Thus, their
               | actual job is to identify that 1% with reasonable
               | accuracy.
        
               | poopbutt7 wrote:
               | How can we forget that- 34 years ago- Pons and
               | Fleischmann made a claim that was incorrect! /s
        
               | mads_ravn wrote:
               | Isn't it just a reasonable application of the
               | "extraordinary claims require extraordinary evidence"?
               | 
               | And I say this as someone really hoping that this is
               | true, since I assume this would be great news for
               | renewable energy (and we really need great news on that
               | front)
        
             | jacquesm wrote:
             | > The bad one consists of sitting in forums and threads
             | being, "the voice of reason".
             | 
             | You put it perfectly. I'm mostly skeptical and very
             | guardedly optimistic because _something_ seems to be
             | happening. But I 've very carefully marked each and every
             | one of my comments with 'assuming this is true' or 'if this
             | is true' to avoid the impression that I'm already
             | convinced. I'm not. But I'm on the side of everybody
             | getting their hands and their lab gear dirty: they are the
             | ones doing the work and they are the ones who put their
             | time (and sometimes their reputations) on the line. That
             | starts off with the original Korean team but also goes for
             | everybody else that has rolled up their sleeves and gone to
             | work. Those people have an audience now, thanks to all
             | these connected media and it's great to see the scientific
             | process acting out in the open for a change where everybody
             | gets to see how the sausage is made.
             | 
             | Meanwhile the Debbie Downers have probably never seen the
             | insides of a lab and have never made anything, they're just
             | taking the default position because it doesn't require any
             | work at all and has the highest likelihood of being true.
             | But I very quietly hope that they're wrong and I also hope
             | that if they are wrong that they will own it. Unqualified
             | negativity is just as dumb as unqualified positivity, it
             | just looks smarter, but it isn't a sign of intelligence.
        
               | SantalBlush wrote:
               | I think the unqualified negativitiy is based on a common
               | misunderstanding of the scientific process, that if one
               | finds any shortcoming in a result--be it applied or
               | theoretical--one can throw the entire work in the trash
               | under the pretense of falsification.
               | 
               | But this is wrong. Science is about weighing the totality
               | of evidence, and refining that evidence in one direction
               | or another over many iterations.
        
               | jacquesm wrote:
               | Indeed, lots of progress was salvaged from failed
               | attempts. In a way _all_ of science is a continuous
               | refinement of our model of how things really work by
               | finding how it definitely doesn 't work.
        
           | stonemetal12 wrote:
           | I think it comes down to a lack of knowledge. I was pretty
           | skeptical of the original claim, since RT has been a goal for
           | a long time and no one has achieved it . So far all the repro
           | attempts I have seen mention temps around 100K. I don't
           | follow SC so 100k sounds "really cold" to me. It matches with
           | my shallow understanding of SC "it is really cold". Maybe
           | that is really warm in SC land. Either way there hasn't been
           | a near freezing repro so I have grown more skeptical of the
           | original claim.
        
             | cthalupa wrote:
             | 100K is very cold. But if this result pans out, it's a very
             | good thing for the possibility that LK99 really is an
             | RTAPS.
             | 
             | There are a lot of explanations as to why they might not
             | see bulk superconductivity at room temp - impurities in the
             | sample (or the impurities being the SC) being the big one.
             | 
             | If LK99 is a superconductor at all, but not a RTAPS, it
             | would be quite strange for the South Korean team to have
             | made a mistake. It's quite difficult to accidentally cool
             | something down to 100K, and if they were just getting false
             | positives on their testing for superconductivity, it would
             | be a massive coincidence that it happened to actually be
             | one at 100K.
             | 
             | We're also seeing a lot of videos that show strong
             | diamagnetism - this doesn't mean it's a superconductor, but
             | all superconductors are perfect diamagnets. We have some
             | unverified videos that seem to show things beyond just
             | diamagnetism, with the material being stable in suspension
             | over a single magnet, which a regular diamagnetic material
             | cannot do. These pieces of material are too small to have
             | been cooled down to 100K and stay there for the duration
             | shown, as well as no frost appearing, etc., which would be
             | quite difficult at that temperature in an environment with
             | any humidity.
             | 
             | I think the bigger concern is around whether or not this is
             | a valid result at all - the Real Deal scientists discussing
             | it seem to have mixed thoughts there, particularly around
             | the noise floor of the instrumentation equipment, etc. Some
             | say that that doesn't matter, others say that it does,
             | particularly since we don't see the kind of on/off drop you
             | would in other superconductors, etc.
             | 
             | At worst, this replication attempt's result is from a
             | misunderstanding of how their equipment works in this
             | condition. At best it provides evidence in favor of LK99
             | being an RTAPS.
        
           | 23B1 wrote:
           | We skeptics have just grown tired of arguing (with everyone,
           | on everything, all of the time)
        
           | 46Bit wrote:
           | Agreed. Even the 100K zero-resistance claim isn't holding up
           | to scrutiny
           | https://nitter.net/condensed_the/status/1686895266329174016
           | https://nitter.net/condensed_the/status/1686901855358427136
           | https://nitter.net/condensed_the/status/1686832552252784641
        
           | throwawaymaths wrote:
           | You're right that this is the worst case scenario, but each
           | interesting replication or semi-replication, even sloppy
           | replication, or theoretical model erodes at that.
           | 
           | Being perma-skeptic is as bad as being a perma-fanboy
           | 
           | Anyways your memory is really short. Don't you remember how
           | when it first came out (not even a week ago) everyone was
           | hollering that it was fake?
           | 
           | Inb4 "extraordinary claims...": there is no _fundamental_
           | reason for superconductivity in general to be impossible at
           | RT.
        
             | jcranmer wrote:
             | > You're right that this is the worst case scenario, but
             | each interesting replication or semi-replication, even
             | sloppy replication, or theoretical model erodes at that.
             | 
             | Not really. The ur-example of the worst-case scenario is
             | cold fusion, and as we were reminded by somebody [1] early
             | on, is that the first replications of the Fleischmann-Pons
             | experiment were actually successful to some degree. Those
             | initial replications were later retracted when it was found
             | that there was experimental error that could observe the
             | same phenomenon, and other replication attempts were
             | reporting outright failure instead of partial success.
             | 
             | > Anyways your memory is really short. Don't you remember
             | how when it first came out (not even a week ago) everyone
             | was hollering that it was fake?
             | 
             | Your memory is really short. The first thread was 8 days
             | ago [2], over a week ago. I've just been perusing those
             | comments quickly, and there's very few accusations of it
             | being fake. The dominant sentiment is along the lines of
             | "big, if true" or "please let it be true", and there's only
             | a few top-level comments casting any shade on its
             | plausibility. But the threads since the weekend have
             | largely seemed to cast aside even the limited skepticism
             | once opined.
             | 
             | [1] I'd love to credit them, but sorry, trying to dig out
             | which comment out of several hundred splayed out across the
             | various early threads was the one I remembered is more work
             | than I can devote at the time. Edit: credit is
             | https://news.ycombinator.com/item?id=36884183, thanks to
             | segfaultbuserr for finding the link.
             | 
             | [2] https://news.ycombinator.com/item?id=36864624
        
               | throwawaymaths wrote:
               | Yeah apologies, I was seeing lots of hot takes that it
               | was fake on other platforms (like Twitter)
        
               | segfaultbuserr wrote:
               | > _I 'd love to credit them, but sorry, trying to dig out
               | which comment out of several hundred splayed out across
               | the various early threads was the one I remembered is
               | more work than I can devote at the time._
               | 
               | It was posted by curiousObject at [1]. I upvoted that
               | thread and participated in that discussion (including
               | adding extra information on why cold fusion experiments
               | were inherently problematic), so I have the link.
               | 
               | As the submitter of the current paper, I'm cautiously
               | optimistic based on the recent theoretical and
               | experimental results. But I strongly agree with you that
               | a repetition of cold fusion's initial false-positive
               | replication "success" is a real risk.
               | 
               | [1] https://news.ycombinator.com/item?id=36884183
        
               | HelloNurse wrote:
               | Fortunately, observing a levitating fleck of diamagnetic
               | material is far less error prone than measuring heat or
               | neutrons in a messy cold fusion experiment.
        
               | throwawaymaths wrote:
               | Exactly this.
        
             | matkoniecz wrote:
             | > Being perma-skeptic is as bad as being a perma-fanboy
             | 
             | Not really?
             | 
             | Perma-skeptic will be far more accurate than perma-fanboy.
             | 
             | Depends on context but for example believing every get-
             | rich-quick scheme will get you robbed by scammers, while
             | perma-skeptic will miss very occasional actual opportunity.
             | 
             | Obviously catching and exploiting great opportunities would
             | be even better, but of these two perma-skeptic is better.
        
               | jacquesm wrote:
               | > Perma-skeptic will be far more accurate than perma-
               | fanboy.
               | 
               | That's not accuracy, that's statistics. Once you bias for
               | the expected outcome the perma skeptic will be just as
               | often wrong or right as the perma optimist. They have no
               | information about the thing they are talking about, they
               | only have information about that expected outcome based
               | on previous observations. If they _had_ information about
               | the thing itself they wouldn 't be wrong for those things
               | that turn out to be true (but then, I guess they wouldn't
               | be perma skeptics to begin with). So, a perma skeptic
               | misses all of the real stuff and a perma optimist misses
               | all of the bad stuff. Neither shows intelligence.
        
               | fallingknife wrote:
               | Perma optimist has more fun, though
        
               | jacquesm wrote:
               | That's a fact.
        
             | atoav wrote:
             | I read through this thread and I can't help to feel
             | reminded of the discussion about cryptocurrencies. So many
             | people that _want to believe_ , rational people that try to
             | explain why it _has_ to work when there is just not enough
             | information right now. As if we believing it will change
             | the outcome of the replication everybody that doesn 't
             | believe is shunned and called a heretic. Suddenly people
             | that studied social sciences try to explain to me (a
             | certified electrical engineer) why this is a big deal,
             | because they saw a few videos on youtube about it, with
             | theories of how this solves all energy problems that are so
             | far removed from practical reality that this can only
             | become a let-down.
             | 
             | Note: I am cautiously optimistic myself, but damn, just
             | wait and don't overhype it.
        
               | kolinko wrote:
               | As for crypto, tgere is nothing to believe in - it's
               | doing well after 14 years.
        
               | atoav wrote:
               | You mean cryptography? Yeah, thanks to let's encrypt we
               | are now reaching widespread adoption of TLS. You barely
               | see any http websites anymore thanks to that.
        
               | jfk13 wrote:
               | You know perfectly well that's not what they meant.
        
               | kaba0 wrote:
               | Cryptocurrencies on the other hand don't seem to be doing
               | all thar well. Their hype-phase is definitely over and
               | not many actually useful use cases remained.
        
               | atoav wrote:
               | Sure, but I am against the idea that from now on "crypto"
               | has to be forever referenced to some ponzi schemes that
               | provide no actual value.
        
               | eric_cc wrote:
               | > I read through this thread and I can't help to feel
               | reminded of the discussion about cryptocurrencies.
               | 
               | Same. Some people are simply wired to be perma-skeptics /
               | perma-bears / perma-negative. This community is still
               | full of people who truly don't grasp how world changing
               | bitcoin is. They are in complete denial, most often
               | parroting unoriginal talking points that they've been
               | handed from others.
               | 
               | It's easier to bypass deep thinking and deep learning and
               | just imitate being an expert. It takes courage to admit
               | being ignorant.
               | 
               | I'll be the first to admit that I'm not an expert in
               | superconductors. I doubt most people in this thread are.
               | But they are parroting and making ignorant predictions -
               | just like crypto.
        
               | cthalupa wrote:
               | I'll not take a personal stance on crypto in this
               | comment, but it's really a stretch to try and compare the
               | two.
               | 
               | No one debates that there are significant and important
               | uses for RTAPS. Lots of people debate if there are
               | significant and important uses for cryptocurrency.
        
               | atoav wrote:
               | As I said I feel reminded of the _discussions_ , I did
               | _not_ compare this scientific finding to crypto-assets
               | per se. What I _did_ however compare is the way this
               | finding is being discussed in comparison to how crypto-
               | assets have been discussed at a certain point in time.
               | 
               | More specifically I was comparing a specific trait of
               | some actors in both of these discussions (the "I want to
               | believe"-type). I stand behind that observation, although
               | I see how people can read more into my comment, depending
               | on where they are coming from.
        
           | cthalupa wrote:
           | > I'm actually surprised by the sheer lack of people
           | commenting in the more-or-less-perma-LK-99 threads who show
           | skepticism of the results.
           | 
           | There's plenty of people that are skeptical and making it a
           | point to tell everyone they are skeptical. There's plenty of
           | people that are skeptical that are still engaging on the
           | possibility of it being real because it is interesting to do
           | so. There are plenty of people discussing potential pitfalls
           | in the papers being written and experiments being done.
           | 
           | But ultimately talking to people in the comments on HN is a
           | form of entertainment for most of the people engaging, and
           | skepticism is a lot less entertaining for most people in
           | general than being enthusiastic and engaging on
           | possibilities. It's not surprising that people going
           | somewhere for engagement and entertainment are doing the
           | thing that is more fun to the majority.
           | 
           | I doubt the majority of people that are excited about it
           | would place serious money on it being true - I sure wouldn't.
           | But I am having fun watching the developments, talking about
           | things to the minimal extent I understand, and thinking about
           | the Cool Stuff that would become possible if we were to
           | suddenly have a new room temp ambient pressure semiconductor
        
             | junon wrote:
             | This. The idea that science can't also be fun seems to be
             | the mindset of a lot of people criticizing others for
             | participating more as eager spectators. Nothing wrong with
             | that. Let people enjoy things. If LK-99 turns out to be
             | nothing then we got some entertainment out of it and a lot
             | of people learned about superconductors (and science in
             | general) in the process. How's that not a win in and of
             | itself?
        
               | _jal wrote:
               | Just to underline this, after years of plague, war and
               | uncertainty, I think this is a great, positive thing,
               | whatever happens.
               | 
               | I'm annoyed with someone I was talking to about this, who
               | either can't or won't stop ranting about past high-
               | profile failures.
               | 
               | Yes, we all know. Old folks like me remember the cold
               | fusion scam first hand. Your knowing cynicism displays
               | deep scientific wisdom. Happy?
               | 
               | Great, now let's watch the fucking show, this is neat,
               | even if it doesn't work out.
        
               | capableweb wrote:
               | I'm guessing some people feel like the time spent
               | discussing/keeping up to date would be a waste of time if
               | it turns out it isn't true.
               | 
               | Which I guess is fine, the friction comes from when those
               | people think others shouldn't "risk" wasting their time,
               | as they start wanting to impose their own will upon
               | others. But this happens all the time with humans so...
        
               | zackees wrote:
               | Cold fusion was replicated by a few labs but that wasn't
               | good enough for the media and they killed it. For
               | background see 60 minutes episode "Cold Fusion is Hot
               | again" where they interview and admit Pons Fleischmann
               | was right.
               | 
               | The difference now is that China is a super power and
               | doesn't have to kiss the ring of the US hegemon.
               | 
               | As an example of replication see
               | 
               | https://www.sciencedirect.com/science/article/pii/S036031
               | 992...
               | 
               | There are many paper like this.
               | 
               | The "cold fusion is a hoax" was in itself, a hoax.
        
               | lucubratory wrote:
               | Journal seems legitimate, but author has a H-index of 7
               | and is making a revolutionary claim that the vast
               | majority of working scientists in the field reject. Why
               | aren't people accepting his work, then? Who is
               | perpetrating this "hoax" you are referencing?
        
               | greenthrow wrote:
               | It's one thing to engage suspension of disbelief when
               | watching a movie. It's another to engage it when
               | discussing actual scientific papers.
        
               | junon wrote:
               | No, it's not. Most people engaging in scientific papers
               | are not themselves scientists in the field. Further,
               | their enthusiasm doesn't change reality. LK-99 is or is
               | not a superconductor. People getting overly excited
               | doesn't change that. Lighten up.
        
             | _0ffh wrote:
             | Ha, I've been talking about the same topic with an
             | experimental physics professor friend of mine. He was just
             | not interested at all, like "I've seen stuff like that so
             | many times before, I'm not interested at this point. I may
             | look at it when there's a publication in a serious
             | journal." while I was like "Hey it's popcorn time, this is
             | a fun ride, whatever the outcome!". =)
        
               | vinnyvichy wrote:
               | Speaking as an academic, I really hope they don't ever
               | publish in a serious journal even if it turns out to
               | replicate. Did your friend take Ranga Dias seriously
               | because that was published in Nature? I understand
               | there's a lot of noise, but one of the things one learns
               | is to cut out noise without having to rely on journal
               | brand
        
               | _0ffh wrote:
               | Nope, he didn't. You're getting the wrong message here.
               | 
               | That publication is _necessary_ to arouse his interest
               | doesn 't mean it's _sufficient_ to make him believe
               | anything. Those are different things.
               | 
               | Peer review for publication is just meant to cut out the
               | obvious crap. It's not a guaranty, and nobody who knows
               | this stuff thinks it is.
        
               | vinnyvichy wrote:
               | Do you even do proofs in your line of work? I'm saying
               | making publication necessary for arousal is a foolproof
               | way to miss out on the beginnings of most of the really
               | interesting stuff. Yeah he can read the ivy-approved
               | materials in nature, but that would be stale. Okay, I can
               | understand that his own line of work is much more
               | interesting to him, that he would ignore the latest
               | glimmerings from adjacent fields. That makes more sense
               | than just taking peer review at face value.
        
               | calf wrote:
               | Several years ago there was publicized a P = NP proof,
               | and during our group meeting I couldn't help but audibly
               | scoff, but our advisor just calmly downloaded the pdf and
               | started skimming it.
               | 
               | It was an object lesson for me. Keep an open mind, use
               | your own competence and intellectual abilities to see for
               | yourself and decide. And only then can you offer
               | insightful criticism.
        
           | TheRealPomax wrote:
           | I'd go one step further. The worst case is they made up data
           | enough to seem plausible, knowing full well replication is
           | impossible, but their institution wanted their name in a
           | major publication so they were told to make shit up and get
           | published.
        
           | jjallen wrote:
           | The reason I don't think this is the case is that they have
           | literally been working on this thing for a quarter of a
           | century. While the people involved are not full on
           | superconductor experts, they are also not super stupid and
           | realize that their claim is a huge one.
           | 
           | How could you work on something for years and years and
           | years, make a claim that it is the first room temperature SC
           | and be _totally_ wrong about it. Even if they only worked on
           | it for ten years, I don't think they are totally wrong.
           | 
           | I think what has happened is that they rushed to publish the
           | paper and the reason it has not been replicated is that they
           | don't even know how to reliably make the material yet. This
           | is why the methods to make it are not in the paper -- because
           | they don't even know how to do it.
           | 
           | Remember they were forced to publish this paper by a rogue
           | former employee.
        
             | verisimi wrote:
             | Can you really be working with a material for a quarter of
             | a century AND not know how to make the material?
        
               | kaba0 wrote:
               | While I have no expertise in material science, it is
               | definitely not some minecraft crafting - depending on the
               | procedure, you may get only few percents of useful output
               | that you may have no way to further purify.
               | 
               | At least for chemistry, it is often a completely
               | different paper that introduces an efficient way for
               | actually mass-producing the given chemical. The first one
               | is more like a proof of concept throwaway code, if we
               | want an analogy.
        
             | blharr wrote:
             | Being wrong in such a complicated field is always possible.
             | Your personal experience and expertise can only go so far.
        
         | brucethemoose2 wrote:
         | Some literature suggests its a "one dimensiononal"
         | superconductor only kinda works in tiny monocrystaline grains.
         | 
         | ...But maybe thats even _more_ interesting for, say,
         | microelectronics? Especially if the resistance orthogonal to
         | the superconductivity is high, if such a thing is even
         | possible?
        
           | wbl wrote:
           | The really cute thing is conducting in one axis insulating in
           | the other two. Then you get to have a very high density
           | interconnect for free.
        
           | frognumber wrote:
           | Such things are possible, and not even very uncommon. The
           | human body has tissues with conductivity different in
           | different dimensions.
           | 
           | If you'd like to create one yourself, take a bunch of
           | parallel insulated wires. Conductivity will be low along the
           | wires, and high perpendicular to them.
           | 
           | Or alternated high-resistivity and low-resistivity sheets.
           | Conduction will be low parallel to the sheets, and high going
           | through them.
           | 
           | Lots of things behave like that.
        
             | monocasa wrote:
             | See also Z-tape.
             | 
             | https://www.3m.com/3M/en_US/p/d/b10167835/
        
             | aziaziazi wrote:
             | > human tissues > isolated wires > alternated sheets
             | 
             | The thinks you describes are systems made of multiple
             | materials. Are you aware of a materials that behave that
             | way by its own ?
        
               | cma wrote:
               | TV rock for a similar thing optically.
        
               | Filligree wrote:
               | No, and LK-99 isn't made of a single material either.
        
               | criddell wrote:
               | How do you mean? It isn't like a wire where you typically
               | have separate insulator and conductor materials, is it?
        
               | aziaziazi wrote:
               | Can you elaborate on that ? For noobs like me, LK-99 only
               | contains Pb9Cu(PO4)6O, doesn't it ?
        
               | baq wrote:
               | Diamond and graphite both only contain C.
        
               | Someone wrote:
               | _If_ some of its properties change depending on the
               | direction you measure, it can't look the same in all
               | directions.
               | 
               | As a simple example, consider graphite. That's just 'C',
               | but the crystalline version is layered, so it behaves
               | differently depending on what direction you look at it.
               | 
               | Like wood, it will split easier when hammered parallel to
               | the layers than when hit oblique to it.
        
               | vingt_regards wrote:
               | Graphite
        
           | ibic wrote:
           | I think you are referring to the pioneer work done by Prof.
           | Chair Tong-seek (or Dongsik Choi as another spelling) here?
           | https://twitter.com/sanxiyn/status/1684437744406392833
           | 
           | Any Korean can give some brief summary over the book that
           | tweets mentioned?
        
             | ssamt wrote:
             | There is a short introduction right on the link.
             | 
             | "The author writes on the influence and meaning of the
             | certain future superconductor revolution on humanity, and
             | while showing similar guise as Western science, he attempts
             | to maintain the notion of the Oriental spirit, the
             | confidence and self-esteem of East Asian scientist."
             | Something like that. I'm not sure what it means.
             | 
             | (Also, yes, Choi Dongsik is probably correct.)
        
           | pjc50 wrote:
           | An even better version of
           | https://en.wikipedia.org/wiki/Anisotropic_conductive_film or
           | "zebra tape", maybe.
        
           | floxy wrote:
           | The one-dimensional things seems like it could make it
           | complicated to measure the resistance. Especially since the
           | bulk material that seems like people are making isn't being
           | laid down in thin films where you might know which direction
           | the conductivity might go. What if there are superconducting
           | grains/domains that abut to each other, but the 1-D paths are
           | then not aligned? Even if you knew that the "domains" were
           | aligned with each other, but didn't know the orientation, it
           | seems like you'd measure a drop-off in resistance, but not to
           | zero at the critical temperature. Maybe?
        
           | ThrowawayTestr wrote:
           | Zero loss diodes seem pretty useful.
        
             | jacquesm wrote:
             | Especially if the material happens to have photo electric
             | properties too...
        
               | fsckboy wrote:
               | ...and gain, at an incredibly fast slew rate!
               | 
               | I mean, we're laundry list fantasizing, right? [shrug
               | emoji]
        
               | jacquesm wrote:
               | Well, yes. _But_ both Silicon, Selenium and Germanium as
               | well as all metals that are shiny are photoelectric. If
               | this thing can form diodes that open a potential path to
               | very high efficiency solar cells. It wouldn 't be the
               | first either:
               | 
               | https://www.nature.com/articles/srep11504
               | 
               | "Origin of photovoltaic effect in superconducting
               | YBa2Cu3O6.96 ceramics"
        
             | mmusson wrote:
             | How would that work? A diode requires a p-n junction
             | created by doping the substrate. It has low resistance in
             | one direction but ideally infinite resistance in the other
             | direction.
        
               | mmusson wrote:
               | I just saw an article that explains the superconducting
               | diode effect https://phys.org/news/2023-08-ubiquitous-
               | superconductive-dio...
               | 
               | So theres the answer.
        
             | distortedsignal wrote:
             | I don't think this would be zero-loss diodes - it would
             | probably superconduct in some x-axis while being non-
             | superconducting in the y- and z-axis. Even then, it's not
             | clear to me what the conductivity is like in the non-
             | superconducting axies.
        
               | [deleted]
        
         | sampo wrote:
         | > The production method is so poorly documented only a fraction
         | of the samples being made shows any interesting properties.
         | 
         | I have understood that rather, the production method is poorly
         | known even to the Koreans themselves, and also they have only a
         | small success rate in their samples. So it's more that the
         | Koreans themselves are not entirely sure what "makes it click",
         | and you can't document it well because you don't yourself know
         | all the details.
        
         | TylerE wrote:
         | Would a ~200K superconductor be useful, if such a beast exists?
         | Obviously not as good as room temp, but at least that's a temp
         | you can maintain with dry ice and not liquid nitrogen.
        
         | kuprel wrote:
         | Why don't they just share the original sample? At least it
         | could offer an existence proof
        
           | xvector wrote:
           | The probability of being able to reproduce this is unknown,
           | there's no reason it couldn't be one in millions.
           | 
           | If the original sample breaks in transit or experimentation
           | we may have lost the only example of a room temp
           | superconductor ever seen.
        
             | WillPostForFood wrote:
             | Invite some scientists and journalists to the lab to
             | observe it?
        
               | WindyLakeReturn wrote:
               | I think they have done that. The catch is that these
               | scientists are likely to take their time, because they
               | want to produce something with weight behind it. This
               | isn't lab #5234's attempt to reproduce it which showed
               | some weird behavior that might be a success, this is the
               | expert report on the original material giving second
               | opinion on how valid the first's claim is. That needs to
               | have more care, which means more thoroughness doing the
               | research and more time spent writing up the final result
               | with care. If lab #5234's attempt ends up being a false
               | positive or experimental error, it will be one of many
               | and won't mean much, but if this particular report is
               | wrong or has a major error, that is going to be impactful
               | in a negative way.
        
         | reacharavindh wrote:
         | With my conspiracy theory hat on, perhaps the authors were
         | encouraged/coerced to not release proper documentation to
         | reproduce the recipe entirely by [their bosses, state agencies
         | etc.] If the claims are true, then the implications to defense,
         | weaponry and such are very high, and the C _|N_ |D* agencies
         | like to not lose their cards in the game.. /conspiracy
         | 
         | Or
         | 
         | Real science is just darned difficult, and the scientists are
         | working hard to reproduce the results themselves. Which is more
         | likely.
        
           | _ph_ wrote:
           | Right. From my own experience, growing crystals is close to
           | alchemy. Of course we know exactly how to do it, yet, it
           | takes a lot of skill to grow a lot of substances. There are a
           | lot of detaills to the process which are difficult to capture
           | in documentation, even if the best faith attempts are made.
           | Add to that any variation in the machinery used. As a
           | consequence, it is quite common in crytallography that there
           | is a single source for certain crytals. At least in an
           | initial phase. If a substance becomes reasonably popular,
           | eventually more people manage to produce quality crystals.
           | 
           | So I would expect eventually good samples to turn up
           | elsewhere as many groups are working on this, but it can take
           | a lot of time. Especially as no one knows what exactly was
           | different about the Korean samples.
        
       | MichaelMoser123 wrote:
       | LK-99 contains polonium? which has a half-life of hundred and
       | something days.
        
         | redox99 wrote:
         | Lol. Polonium is Po. PO is phosphorus and oxygen.
        
           | MichaelMoser123 wrote:
           | thanks!
        
             | More-nitors wrote:
             | guess it's safer to eat :)
        
               | rvnx wrote:
               | Only in a tea.
        
       | [deleted]
        
       | anonymousDan wrote:
       | Can someone point me to a list of exciting applications of room
       | temperature superconductors? Trying to understand why such
       | excitement about this!
        
         | tetris11 wrote:
         | >
         | https://en.m.wikipedia.org/wiki/Technological_applications_o...
        
       | [deleted]
        
       | EvgeniyZh wrote:
       | Note that there is no signs of phase transition (no jump) and the
       | values below 110K are around reasonable measurement resolution.
       | It may be that they just got the resolution threshold and
       | misinterpret it as SC
        
       | squirrel_fetus wrote:
       | Pretty cool! The question is how cool?
        
         | segfaultbuserr wrote:
         | According to the paper: Tc = 110 K, or around -163 degC. This
         | is still pretty "cool", the existence of room-temperature
         | superconductivity remains unverified. But assuming this paper
         | is true, it means the material would still at least be a
         | legitimate high-temperature superconductor in its own right,
         | and the original claim would probably be cleared from being a
         | deliberate fraud.
        
         | jfengel wrote:
         | Cooler than dry ice but less cool than liquid nitrogen.
         | 
         | (Wakka wakka wakka)
        
       | febusravenga wrote:
       | I see lead (Pb...something) as main ingredient, isn't it banned
       | in most industries because how toxic it is and how hard it's to
       | handle in industrial scale? isn't that a problem for potential
       | mass applications?
       | 
       | (lots of comments about this discovery call this revolution that
       | will change everything around us and that somehow implies mass
       | production I guess)
        
         | gtsteve wrote:
         | If this discovery is confirmed then someone will figure out how
         | to do this safely, using robots or other kinds of machines to
         | produce superconductor wires. The benefit derived would be
         | simply too great to ignore it. Perhaps superconductors don't
         | show up in your home but I can certainly imagine applications
         | in optimising power grids.
        
         | thomasmg wrote:
         | Lead is still used for example in car batteries (lead-acid),
         | bullets, and solders (electronic components).
        
           | cycrutchfield wrote:
           | Airplane fuel...
        
         | pjc50 wrote:
         | It's banned in the EU under RoHS .. but with a whole load of
         | exemptions, which make it kind of pointless. I suspect this
         | would be exempted pretty quickly once it became important.
        
         | [deleted]
        
         | kolinko wrote:
         | A high chance that lead can be replaced with other metal, from
         | what I heard.
         | 
         | Also, it's not extremely toxic - romans ate from lead dishes
         | and didn't even notice the toxicity.
         | 
         | You don't want to consume it, and you don't want to breathe it,
         | but it's not as bad as say, asbestos.
         | 
         | If you have an ICE car, it probably has a lead-acid battery,
         | and the only thing that prevents us from using lead in grid
         | storage is their short lifespan - not health or ecology :)
         | 
         | Also, if you ever took an x-ray, you wore a lead jacket to
         | prevent unnecessary radiation.
         | 
         | If we cannot avoid lead in this alleged superconductor, it may
         | limit applications slightly, but not by much.
        
           | yreg wrote:
           | Tesla has a lead-acid 12V battery as well :)
        
       | [deleted]
        
       | crakenzak wrote:
       | So exciting!
       | 
       | Just FYI, the wikipedia page for LK-99 has a very useful tracking
       | grid of replication attempts with sources:
       | https://en.wikipedia.org/wiki/LK-99
        
         | Filligree wrote:
         | That grid is a direct copy of this one here:
         | https://forums.spacebattles.com/threads/claims-of-room-tempe...
         | 
         | ...but isn't sourced, presumably because they don't consider SB
         | to be professional enough.
        
           | capableweb wrote:
           | Does not seem to be a direct copy (the Wikipedia missing
           | things like Progress/Status, Reliability of Claim) and also,
           | the Wikipedia page can be collaboratively kept up to date,
           | while the other is a random forum post "owned" by one user
           | and the owners of the platform.
        
         | awb wrote:
         | The Response and Replication sections on Wikipedia seem far
         | more skeptical and pessimistic about LK-99 than the average HN
         | comment or news article.
        
         | silisili wrote:
         | I'm curious why every tracker lists Argonne, though no status
         | or progress listed. I'm sure there are a hundred other labs
         | who've either done nothing, or are doing something without
         | fanfare, so why Argonne?
        
           | JustARandomGuy wrote:
           | Argonne is a highly regarded national lab; results from there
           | would be highly credible. Also an Argonne staffer has gone on
           | record[0] saying that they're attempting to replicate, while
           | other labs have not said whether they're trying or not.
           | 
           | Personally I'm waiting for the Argonne results which should
           | be done by the end of the week.
           | 
           | [0] https://www.science.org/content/article/spectacular-
           | supercon...
        
             | adamsmith143 wrote:
             | With you there. A lot of Chinese labs are listed e.g. but
             | my own experience trying to replicate materials science
             | results from "credible" Chinese labs has led to a lot of
             | disappointment.
        
           | Levitating wrote:
           | All the labs on that list have stated that they are working
           | on replicating the experiment. That's also what is
           | referenced.
        
           | psychphysic wrote:
           | Anyone can edit Wikipedia.
        
             | mycologos wrote:
             | Yes, in particular, anyone can add citations that you can
             | check if you're skeptical. In this case, the citation is an
             | article from science.org [1], which includes the following
             | quote:
             | 
             | > "They come off as real amateurs," says Michael Norman, a
             | theorist at Argonne National Laboratory. "They don't know
             | much about superconductivity and the way they've presented
             | some of the data is fishy." On the other hand, he says,
             | researchers at Argonne and elsewhere are already trying to
             | replicate the experiment. "People here are taking it
             | seriously and trying to grow this stuff."
             | 
             | [1] https://www.science.org/content/article/spectacular-
             | supercon...
        
               | dmarchand90 wrote:
               | What makes me excited is there is very good theoretical
               | work, using 'standard techniques ' that shows it either
               | is a superconductor or will have very good properties in
               | designing one.
               | 
               | Cold fusion, the EM drive, time traveling neutrinos, and
               | all the other false excitement never had a theoretical
               | backing. So 'guarded optimism' seems warranted
        
         | swagmoney1606 wrote:
         | We'll probably know for sure within the month!
        
           | generalizations wrote:
           | Somewhat disappointed the russian twitter anon isn't
           | included, since they seem to have made the first replication
           | attempt that might have panned out.
        
             | sashank_1509 wrote:
             | Anon is fine, I'm inclined to promote anons who do credible
             | replications. Russian anon is not one of them, she really
             | should take a video at the very least, even then her speck
             | is so small until she released detailed measurements one
             | can't in good faith trust her. I won't be surprised if at
             | the end of all this, she just claims she was trolling in
             | good fun and we're the fools for taking anything she says
             | seriously.
        
               | Workaccount2 wrote:
               | >I won't be surprised if at the end of all this, she just
               | claims she was trolling in good fun and we're the fools
               | for taking anything she says seriously.
               | 
               | Ahhh, you gotta love the internet
        
             | yreg wrote:
             | Ah this again. No offense to you, but yes, the obnoxious
             | anonymous Russian troll who's only proof is a photo of a
             | spec of dust (glued?) in a syringe, who refuses to take a
             | video, who says she didnt follow the paper beause she
             | immediately invented a better way to make a different room
             | temp superconductor, who says she doesnt care about
             | superconductors and who keeps tweeting bizzare USSR
             | propaganda?
             | 
             | I wonder why she's not included in the Wikipedia article.
             | /s
        
             | lost_tourist wrote:
             | I suspect that account is just a troll who knows a bit
             | about material science. They spend more time arguing and
             | promoting the Soviet Union than sciencing. I gathered that
             | after just 5 minutes of scrolling through their twitter. I
             | suspect a retired and bored Soviet scientist maybe?
        
             | dclowd9901 wrote:
             | Iris? That person comes off as completely unhinged. If
             | their result is genuine, I'll eat my curtain.
        
       | sedatk wrote:
       | Off-topic, but I admire the effort to translate the formula to
       | Unicode characters in the title. It's not just a simple copy-
       | paste from the article.
        
         | Arnavion wrote:
         | The submitter also fixed the incorrect use of the degree symbol
         | before K, lol.
        
           | 8n4vidtmkvmk wrote:
           | "degrees Kelvin" is wrong? Why's that?
        
             | rsfern wrote:
             | The SI unit is just "kelvin" because it's an absolute
             | scale. Usually "degrees" is only used with Celsius and
             | Fahrenheit scales because they are relative. Not sure about
             | Rankine...
             | 
             | https://www.nist.gov/si-redefinition/kelvin-introduction
        
               | archon1410 wrote:
               | > zero on the Rankine scale is absolute zero, but a
               | temperature difference of one Rankine degree (degR or
               | degRa) is defined as equal to one Fahrenheit degree
               | 
               | But Rankine is an absolute scale. "By analogy with the SI
               | unit, the kelvin, some authors term the unit Rankine,
               | omitting the degree symbol."
               | 
               | https://en.wikipedia.org/wiki/Rankine_scale
        
               | rsfern wrote:
               | Ah, interesting - this NIST page uses degR, which is at
               | odds with the explanation in the other page on Kelvin
               | (which doesn't mention Rankine). I'm not sure if that's
               | because there's a strong convention to use the degree
               | symbol with Rankine or if there's an additional reason
               | not mentioned by the Kelvin page
               | 
               | https://www.nist.gov/pml/special-publication-811/nist-
               | guide-...
        
             | Arnavion wrote:
             | Technically the units of temperature are "degrees Celsius",
             | "degrees Fahrenheit", "Kelvin", etc. ie "degrees" is part
             | of the name of the units "degrees Celsius" and "degrees
             | Fahrenheit". "Kelvin" is the name of the unit by itself, so
             | "degrees" is not supposed to be used before Kelvin.
             | 
             | In practice everyone's so used to saying "degrees" for
             | temperatures that they end up saying it with Kelvin too.
        
         | LightMachine wrote:
         | GPT-4 does it very well though. (Not saying OP used it, was
         | just curious if that'd work.)
         | 
         | Prompt:
         | 
         | > Observation of zero resistance above 100[?] K in
         | Pb10-xCux(PO4)6O
         | 
         | > convert this to a title, with the correct usage of unicode
         | 
         | Output:
         | 
         | > Observation of Zero Resistance Above 100 K in
         | Pb10-[?]Cu[?](PO4)6O
        
           | 1letterunixname wrote:
           | ChatGPT says:                   The chemical formula
           | "Pb10-xCux(PO4)6O" can be written in Unicode as follows:
           | Pb10-[?]Cu[?](PO4)6O              Please note that not all
           | characters may be perfectly aligned due to font
           | variations and rendering differences in different systems.
           | However, this          representation should provide a close
           | approximation to the chemical formula.
           | 
           | As plain text: Pb10-[?]Cu[?](PO4)6O
           | 
           | EDIT: Note that arxiv uses mathjax (JS) to take a compound
           | formula as plain text and applies subscript, superscript,
           | etc. styling to it. ("Pb10-xCux(PO4)6O")
        
           | sedatk wrote:
           | Wow, I would've never thought to use ChatGPT for this. Very
           | cool.
        
             | cooper_ganglia wrote:
             | I use ChatGPT as a word calculator for literally everything
             | all of the time. It's super great for achieving proper
             | formatting easily!
        
               | qingcharles wrote:
               | Indeed. I always tell it to use proper fancy quotes and
               | proper apostrophes in its output, but I can't get it to
               | do it 100% of the time despite trying out many prompt
               | variations and telling it the Unicode values etc etc.
        
       | hcks wrote:
       | - it's an easy to make room temperature superconductor!
       | 
       | - ok it's hard to make but still RTSC!
       | 
       | - ok it's superconducting at 100K but its a novel class of SC! <=
       | _you are here_
       | 
       | - ok it's not a superconductor but it still has interesting
       | properties!
       | 
       | - ok it doesn't have singular properties but it could have!
       | 
       | I predict there will still be LK99 truthers in 20 years arguing
       | that this amazing discovery was buried by big copper conspiracy.
        
       | ajnin wrote:
       | I'm puzzled by this, looking at the resistance versus temperature
       | graph they're not demonstrating zero resistance at 110K, they're
       | demonstrating that at 110K the resistance becomes so low that it
       | reaches the noise floor of their instrument. It's a stretch to
       | call that superconductivity because when it come to that it needs
       | to be actually zero, as in "I can put a current in a loop made of
       | the material and come back one year later and it will still be
       | there". Exponential decay will quickly catch up with a non-zero
       | value, even very very small. Still this exponentially decreasing
       | resistivity looks interesting, I have no idea if that's unusual
       | or if that means anything. The weird dip at around 230K will need
       | to be explained as well. I'm just an interested bystander, that
       | goes without saying.
        
         | Loughla wrote:
         | Really, really, really Stupid question (yes, capital S stupid).
         | Several hypotheticas here that got me thinking:
         | 
         | If superconductor exists at room temperature, and if I
         | understand you correctly, it can hold a charge, essentially,
         | indefinitely.
         | 
         | Could I get a roll of it and charge it and throw it at someone
         | to kill them? Or could I fry a passing car by throwing it at
         | the car?
        
           | segfaultbuserr wrote:
           | You certainly can use it as a batteryless inductor coil to
           | zap people, similar to how you zap people with a charged
           | capacitor. But a superconductor is limited by the magnetic
           | field strength it can support. When the magnetic field
           | strength goes up beyond the critical field by increasing the
           | current, superconductivity is lost. In superconducting
           | magnets, this causes a catastrophic failure called a "magnet
           | quench". So a superconductor cannot store unlimited energy.
           | In the original LK-99 claim, the critical current is 200 mA,
           | it's not much.
        
         | Sharlin wrote:
         | Well, that's one of the reasons demonstrating the Meissner
         | effect is considered a better evidence of superconductivity. Of
         | course _any_ physical experiment always has a noise floor and a
         | finite error. You can 't exactly ever measure zero resistance
         | because your probes and the probe-sample interface have nonzero
         | resistance...
         | 
         | But looking at that graph, it would be an incredible
         | coincidence if the resistance dropped like it does and then
         | suddenly stabilized to some very small but nonzero value...
         | That would probably require entirely new physics to explain and
         | would be a much bigger news than "merely" a 110K Tc
         | superconductor!
        
           | foven wrote:
           | Groups that typically do resistivity measurements on
           | regularly measure low-temperature resistivities on conducting
           | materials of ~ 10s of micro Ohm m. So if you're measuring in
           | this range on a conducting material and hitting the noise
           | floor with a SHARP drop, that's a pretty big indicator of
           | superconductivity (assuming you haven't just broken your
           | contacts which is a concern when cooling things down). I'm
           | not so familiar with PPMS systems, but I imagine it has some
           | built in auto-adjust on the sensitivities to where you can be
           | pretty confident your noise floor is below these values.
           | 
           | What is complicating the interpretation here is the log scale
           | (and lack of conversion to resistivity): It is amplifying the
           | impression of the noise below what they call Tc, and making
           | it harder to interpret the approach of the material to the
           | transition point. The behaviour at the approach to Tc also
           | doesn't really look like a metal, which should scale as
           | propto T, or a semiconductor which should increase with
           | decreasing temperature. Possibly a result of it being some
           | horrible mixed phase ceramic.
        
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