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As I feared, it is no use at all at this stage to claim anything about LK-99 as every synthesized LK-99 seems different each time. We have to have a thorough an
by ayakang31415 3y ago
As I feared, it is no use at all at this stage to claim anything about LK-99 as every synthesized LK-99 seems different each time. We have to have a thorough analysis on the sample directly provided by Lee and Kim.
- Accujack 3y agoOr everyone has to wait for the full paper to be released which supposedly includes some manufacturing steps not included in the leaked paper so that replication can happen properly. The original samples are now under testing at a national lab in SK.
- brucethemoose2 3y ago> We have to have a thorough analysis on the sample directly provided by Lee and Kim. Even this sample could be marginal, going by the original paper. But there has been plenty of "locked" levitation and lots of zero conductance failures. I believe LK-99 a finicky topological superconductor thats going to give researchers headaches for years, not something that will suddenly be a bulk superconductor with just the right synthesis in the coming months.
- whatshisface 3y agoLevitation with a corner touching the magnet can be accomplished by iron. It's what iron filings do when you put them on a magnet!
- brucethemoose2 3y agoThere have been multiple videos of tiny LK99 specs completely levitating on single magnets, and resisting motion when pushed, and staying afloat when the magnet is inverted. That is not possible in any known material. Unless thats an array of very elaborate fakes, its a RT superconductor. But the simulation papers and conductance tests make me suspect its a topological superconductor that would fail such tests.
- marcosdumay 3y agoI haven't seen any such video with a high credibility stance after it, like the author using the real name.
- carabiner 3y agoAre any of those from legit research institutions? I know there have been a bunch of fake hover videos in the past 48 hours.
- drdeca 3y agoI thought there was just one video of it completely levitating, and that that one was somewhat questionable (having an unclear source, and being deleted by original poster)? Do you have a link to more than one showing complete levitation?
- hackerlight 3y agoI recall one showing full levitation (BilliBilli anon poster). If there is a different video, the poster above should link it.
- fnordpiglet 3y agoThe iris videos were full levitation
- rrssh 3y agoWe distinguish between videos and photos in this context.
- Jweb_Guru 3y agoIris photo is completely unconfirmed outside of "Twitter likes her." She said she would make a video over a week ago and never did. Additionally, due to the fleck being confined to a tube, it would not fall afoul of any proofs about ordinary ferromagnetic levitation being impossible.
- 3y ago
- penjelly 3y agothank you for providing nuance
- cptaj 3y agoThis is my intuition as well. Hopefully the controversy doesn't cloud researcher's judgement and cause us to miss out on the technology just because it was way more nuanced than first appeared. It might also be that everyone loses interest and the original team get the extra time they needed to work in peace and make a comeback.
- lumost 3y agoUnfortunately such bold claims can strongly effect researchers ability to work on this in the future. The original cold fusion release has had an overhang on any studies of low energy nuclear reactions. Regardless of whether they have any bearing on energy production. As an example of this, it is obvious and known that metallic lattices can lower the energy barrier of a nuclear reaction. However the underlying physics of how much screening and when is illusive - and their is a high correlation of quackery with any attempts at studying these systems. https://www1.grc.nasa.gov/space/science/lattice-confinement-fusion/ https://www1.grc.nasa.gov/space/science/lattice-confinement-...
- deleted 3y ago[deleted]
- archgoon 3y ago> Even this sample could be marginal, going by the original paper. If the sample they claim is superconducting isn't superconducting; why should we assume that this material is a superconductor at all? Because of some vague idea that their prof thought it might be more than 2 decades ago?
- Jweb_Guru 3y agoThat's exactly where I'm coming from here. The original evidence that had people cautiously optimistic has been thoroughly dismantled. It's not showing any unusual or inexplicable signs of superconductivity: no anomalously high diamagnetism, no anomalously low resistivity or IV curves, no heat capacity differences, it lacks a theoretical model, and all anomalous measurements can be completely explained in terms of known or predicted properties of its constituent materials. I don't even need to bring up the lack of credibility of most of the members of the lab, HT Kim's crackpot tendencies, or the fact that Qcentre misrepresented its affiliations for it to be clear that there's nothing to the original paper. Yet people are arguing "it might still be a superconductor! Just an exotic type that no one can replicate and also doesn't look like a superconductor in any measurements!" Okay, so could any number of other compounds, many of which are far more promising than this one (e.g. some USOs have shown actual definite diamagnetism). Why should we care about this one?
- gehwartzen 3y agoPeople always underestimate how much time physical science takes and how small normal steps are. my favorite xkcd: https://xkcd.com/683/ https://xkcd.com/683/
- kijin 3y agoCalling it "LK-99" seems to have been a mistake. It gives the impression that the term refers to a well-defined material, perhaps even a mass-produced product like "iPhone 14" or "RTX 4080". This explains all the calls for the original authors to send samples, as if you were ordering from AliExpress. In reality, what we have is a family of lead-copper-phosphorus-oxygen compounds, each with a different crystal structure, some of which might or might not exhibit interesting properties. If this hype doesn't fizzle out soon, scientists will probably converge on more neutral, precise terminology to refer to the various configurations in order to avoid talking past one another. Something like β-LK99-Cu-5-7.
- Osmium 3y agoScientists already have well-defined terminology for many of the crystal structures described, the LK-99 is just a shorthand for this synthesis product (and a convenient one at that, for anyone trying to keep up with the latest). I wouldn’t be too concerned! Part of the reason we’re not using a full formula yet is that we don’t precisely know what it is (or, indeed, if it’s just one thing at all; the linked paper makes a good argument that this will necessarily be a mix of multiple phases if synthesized as-described). Once we know what it is, we can use one of several existing names.
- kijin 3y agoThere should be a middle ground somewhere between an unwieldy chemical formula and a catchy product-like name. For example 3,4-MDMA is a useful shorthand for people who want to be precise as to which isomer they're talking about, but don't want to spell out 3,4-methylene-dioxy-methamphetamine every time.
- ThePhysicist 3y agoIt seems people are throwing around more and more random physics keywords without any type of evidence. What makes LK-99 a topological superconductor? Topological quantum states and the associated Majorana fermions have only been observed in their bound state so far (and only in highly engineered quantum systems), and there's absolutely no indication that they should exist in that material, at least I don't see how you could postulate that by observing levitation or measuring an IV curve in a bulk sample.
- SanderNL 3y ago[flagged]
- highwaylights 3y agoSpeaking as a layperson and casual observer, I understood some of the words in this thread.
- klabb3 3y agoI think you may have been duped by an LLM. I’m glad someone is finding a real use case for it, I just wish it were somewhere else.
- computerfriend 3y agoI don't think an LLM is capable of this kind of sarcasm (yet).
- kergonath 3y agoI thought there were rules against using ChatGPT in comments here. (For the uninitiated, this is a bunch of gibberish with a few science-y keywords for truthiness).
- SanderNL 3y agoI transgressed and take full responsibility. Couldn’t resist.
- delabay 3y agoThe quality and depth of the analysis here far exceeds the work done by the original Korean team. It is very unlikely the Korean team has successfully manufactured the Cu-doped phase given the thermodynamic mountain required to climb, and its clear anybody attempting to replicate their recipe was essentially producing a random assortment of garbage. The Korean team needs to disclose any alternative formulations or just accept failure and move on.
- ayakang31415 3y agoThe original Korean team paper was supposedly a rushed job because of inside fight at the research center, so it is expected the quality is poor by default. We still have to wait for a more polished proper research paper from the team to judge whether it is legit or not (APL material is their choice of journal I believe). We can speculate whether the Korean team has achieved superconductivity or they are under delusion based on replication papers published on arxiv, but such papers have never come under the scrutiny of peer review process as well. So I would reserve my conclusion about this at this stage. It is just frivolous to say whether LK-99 is superconductor or not for now.
- haldujai 3y ago> but such papers have never come under the scrutiny of peer review process as well. Except that such pre-prints far outnumber the supportive pre-prints, are from verifiable scientists at reputable institutions, are in agreement with each other, and are not making claims of a shocking scientific breakthrough. As there is no substantial evidence to support superconductivity claims it's reasonable to dismiss them until said group decides to provide evidence. If you recall the burden of proof is on the one making the claim. > It is just frivolous to say whether LK-99 is superconductor or not for now. I don't think it's frivolous given the distraction and resource-sink this has been.
- thkim 3y agoOriginal authors have been working on it for 23 years since they first found the material in 1999. They are part of private institution and have no incentive to rush the disclosure so that other labs can catch on their life's work. Authors already have stated they will publish more information next year. It's pretty arrogant to draw premature conclusions on quick analysis and demand the authors to disclose more information right now, when they are clearly not obligated to anything.
- bhouston 3y agoI disagree. I think that given the multiple failed attempts from numerous top tier labs we should say this isn’t a SC unless L&K share their sample and it proves to be. Replication has failed pretty thoroughly.
- threeseed 3y ago> Replication has failed pretty thoroughly As everyone seems to keep forgetting the original scientists said that less than 10% of their replication attempts was successful. We don't have 10 replications total let alone 10 based on their exact process which is unknown to everyone except them at this point. So not sure on what basis you can claim replication has thoroughly failed.
- whimsicalism 3y agoThey have been able to replicate the levitation and then shown that it is not due to SC but ordinary ferromagnetism
- threeseed 3y agoWhich is a useful data point. But the wide variety of samples indicates that there isn't convergence yet on what the intended process is. Until that happens any conclusions are just data points - nothing more, nothing less.
- whimsicalism 3y agoThe fact that they were able to replicate the original effect (what people thought was flux pinning) that made everyone think it is superconductivity and then conclusively show that it is not superconductivity is pretty strong evidence.
- versteegen 3y agoThat's exactly what I thought at first. And then I realised that the 'ferromagnetism+diamagnetism' article does not actually provide a mundane explanation of the "half levitation": They estimated that their sample had very strong diamagnetism -- at least the 2nd strongest of any known (non-SC) substance, assuming their sample was pure (but we can assumeit isn't, considering that they just had one tiny flake levitate), so quite possibly the strongest. And superconductivity is a possible cause of diamagnetism. It still hugely weakens the levitation effect as evidence for SC, but "conclusively show that it is not superconductivity" is not quite true.
- fouc 3y agoeh, most of the synthesized LK-99 out there by the different teams share enough commonalities and seem very promising from the levitation/flux pinning effects.
- gehwartzen 3y agoHonestly I'm excited by that. Seems like a big space opened up for exploration. I think over the next few years there will be several types of this composition with varying electro-magnetic properties.
- hcks 3y ago> let’s invest even more time and resources on what doesn’t look at all like a dud
- belter 3y agohttps://news.ycombinator.com/item?id=37060775 https://news.ycombinator.com/item?id=37060775
- MissingAFew 3y agoOr Beijing, since they apparently have fully replicated it. https://arxiv.org/abs/2308.04353 https://arxiv.org/abs/2308.04353 I don't know why so many institutions and scientists are so quick to call it nothing. It feels like hubris to me, the scientists in Korea spent many years on it, if it were so easy to dismiss I don't think that would have continued their research... right?
- radioactivist 3y ago> The superconducting-like behavior in LK-99 most likely originates from a magnitude reduction in resistivity caused by the first-order structural phase transition of Cu2S The preprint you are citing is explicitly dismisses the sharp transition seen as being non-superconducting.
- MissingAFew 3y agoNah, I know. But it still looks like a similar material, no? Even if it looks unlikely to be superconducting, I still think people should remain level headed about it. They spent a lot of time and effort on it.
- EvgeniyZh 3y agoWell Occam's razor is to rescue. As for now "LK-99 is not superconductor" is the simplest claim consistent with all experimental evidence. That's not awfully specific, but since specifics are not very impactful, people won't rush to clarify it. If anyone (probably original authors) provide something that contradicts this claim then we'll need to revise it