Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O
arxiv.org
arxiv.org
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.
...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?
I mean, we're laundry list fantasizing, right? [shrug emoji]
https://www.nature.com/articles/srep11504
"Origin of photovoltaic effect in superconducting YBa2Cu3O6.96 ceramics"
So theres the answer.
Any Korean can give some brief summary over the book that tweets mentioned?
"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.)
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.
The thinks you describes are systems made of multiple materials. Are you aware of a materials that behave that way by its own ?
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.
A lot of materials (including any crystal) have a sense of direction.
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.
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.
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.
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.
Note: I am cautiously optimistic myself, but damn, just wait and don't overhype it.
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.
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.
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.
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.
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.
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.
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).
People are way, way overconfident. 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.
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%.
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.
Only one of the four labs that completed replication has claimed to have found diamagnetism, but how could that video be explained otherwise?
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)
Maybe there's a lot of smoke and no fire, but there's videographic evidence of something weird going on.
Why would different newspapers spread hoaxes? Yet it happens...
Poor source checking and then issuing a retraction is not the same as a conspiracy among the papers to make something up completely.
you couldn't, suggesting that it isn't true
by the way, you forgot to respond to [0]
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.
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
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.)
Cold fusion always was dependent on new physics to be discovered
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.
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.
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.
> 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?
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.
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
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.
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.
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.
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...
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/S036031992...
There are many paper like this.
The “cold fusion is a hoax” was in itself, a hoax.
This proverbial gun is disabled if there is abundant decentralized power generation they don’t control.
Just look at the oil shutdown at Niger.
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.
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.
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.
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.)
Finally you could create fields of expertease for every account (upvoted comments keywords) and ban threads with non-experts majority commenting.
Something like http://www.paulgraham.com/spam.html but fine tuned to flamewars? Perhaps. The mods have some easy automatic criteria, the flags, vouches and upvotes from users, and then apply manual moderation on top of that.
It may be hard to distinguish a good discussion about a war from a bad discussion about icecream. Or replace war and icecream with your favorite topics.
> Also, i guess length of comment might be a strong indicator of thread degeneration.
I like that. Very short comments are usually bad, but huge wall of text too. Perhaps they have something more advanced and never told us. It may be part of the secret sauce. (Or it may be good that they pretend they have advanced stuff, so people behave better.)
> Finally you could create fields of expertise for every account (upvoted comments keywords) and ban threads with non-experts majority commenting.
It's an interesting idea, but my guess is that it's too hard. I'm not sure which tags apply to me. In some topics I'm mathematician, but I comment a lot in physics stuff because I have an unfinished degree in physics. But it depend on the area. In some areas I know a lot and in others I can just skim the article and look at the graphics. [1]
My guess is that non-experts are always the majority. For me the important part is that the comments by experts float near the top. There are also some interesting comments from non-experts, sometimes with a good reply from an expert. Upvoting good comments is very important to make the discusion better.
[1] Protip: Reading medicine studies, remember to Ctr+F "exclusion", because sometimes after the study started they excluded some of the subjects, like the guy that had 100% success after excluding the 1 dead and 5 other weird cases.
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.
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.
But this is wrong. Science is about weighing the totality of evidence, and refining that evidence in one direction or another over many iterations.
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.
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.
Reasonable skepticism is always warranted. I think this thread is talking about reflexive cynicism and instantaneous dismissal.
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)
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.
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."
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
Agents of reason, please enlighten us with your eternal negativity so that we may perceive clearly the folly of our excited ways.
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.
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.
If the original sample breaks in transit or experimentation we may have lost the only example of a room temp superconductor ever seen.
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.
Or
Real science is just darned difficult, and the scientists are working hard to reproduce the results themselves. Which is more likely.
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.
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.
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.
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.
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.
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.
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?"
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!
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.
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.
Would semi-conductor like properties result in something like this - thermal noise pushing electrons into the band gap?
Logarithmic plots are a device of the devil. - Charles Richter
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
I wonder why she's not included in the Wikipedia article. /s
Ahhh, you gotta love the internet
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...
> “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...
Cold fusion, the EM drive, time traveling neutrinos, and all the other false excitement never had a theoretical backing. So 'guarded optimism' seems warranted
…but isn’t sourced, presumably because they don’t consider SB to be professional enough.
- "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 :)
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..
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".
Also, it's not true at all the retraction have no consequences. It is an indelible mark of shame.
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!
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.
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?
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.
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?
> 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.
You know, because hype.
This is, as the kids say, very bullish.
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".
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).
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.
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.
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 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.
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.
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.
Hopefully more rigorous testing will be done by one of the teams later.
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/...
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.
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.
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.
Gulp!
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.
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!
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...
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.
If we simply decided to make this kind of thing a priority, we could probably manufacture suspension components at scale. (Or create small tunnel boring machines and bury them?) We wouldn't need to replace all of the lines. We'd just need enough interconnects to make transferring more power economical.
Probably if we had materials with a billionth of the resistance of silver they would work, but we haven't. And we have superconductors, luckly. :)
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.
There is no work or state change, so no reason at all to conflict with the 2nd law of thermodynamics.
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.
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?
At micro levels, like molecules bouncing around in a gas, collisions are lossless. What makes electrons moving through materials different?
> 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.
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.
(Wakka wakka wakka)
The UFOs are a PSYOP.
https://phys.org/news/2019-02-navy-patent-room-temperature-s...
> 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.
> 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"
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.
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).
In conclusion, ... nothing?
But with how difficult the samples production seems to be, maybe we will get 400 K superconductors still
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.
- 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.
Still waiting for confirmation from multiple labs.
'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.
Possibly because the sample includes too many impurities.
Edit: I read 100 K as 100°c. Mea culpa.
Fool me once...
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...
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.
I am sure defense folks would have a field day with new sensors with virtually no thermal noise.
I think the thing solves our environmental issues is actually industrial electrolysis, because then it doesn't really matter what your power source is, you have a means of decarbonizing chemical processes, and an incentive to commoditize carbon. Essentially, waste would have value, because it's a cheap source of carbon that can be used with hydrogen to create methanol, dme, etc. Not to mention, hydrogen salt cavern storage is proven at scale for 4 decades now to the tune of 350GWhs or so, and it lets us decarbonize agriculture and cement production.
I guess fusion might help make energy cheaper for these processes, but I don't really see that it matters if they're powered by fission or wind and solar. But if we can't get electrolysis cheap enough, then I don't see these processes being decarbonized until we're almost out of fossil fuels.
My 2c, anyway.
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.
(lots of comments about this discovery call this revolution that will change everything around us and that somehow implies mass production I guess)
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.
Replication has been partially successful, exhibiting remarkable new results that are already worth celebrating.
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".
In practice everyone's so used to saying "degrees" for temperatures that they end up saying it with Kelvin too.
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://www.nist.gov/pml/special-publication-811/nist-guide-...
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₋ₓCuₓ(PO₄)₆O
The chemical formula "Pb10−xCux(PO4)6O" can be written in Unicode as follows:
Pb₁₀₋ₓCuₓ(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.
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")
Plenty of reason to doubt it though. Of course I'm hoping it's real.
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.
What we know is that LK-99 looks pretty interesting. Is it a room-temperature superconductor? Maybe!
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.
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.
(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?)
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.