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.
> 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.
> 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
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.
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.
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.
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.
> 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.
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."
> 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.
> 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.
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.
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.
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.
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?
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?
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.
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.
> 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.
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.
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.
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.
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.
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.
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.
> 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.
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.
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?"
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.
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.
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.
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?
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.
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 :)
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..
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 -100°C (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".
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.
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!
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.
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.
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.
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".
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.
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.
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 Ω (!) 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.
The resistance curve stopped at 1e-5 Ω 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.
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.)
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.
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.
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.
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.
Readit News
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.
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.
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
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.
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.
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.
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.
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."
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.
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.
> 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?
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.
...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?
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.
Any Korean can give some brief summary over the book that tweets mentioned?
If the original sample breaks in transit or experimentation we may have lost the only example of a room temp superconductor ever seen.
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.
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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'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.
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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?"
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
…but isn’t sourced, presumably because they don’t consider SB to be professional enough.
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...
- "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".
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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.
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".
> 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
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?
You know, because hype.
This is, as the kids say, very bullish.
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.
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