We now believe that the game is over. LK-99 is not a superconductor
twitter.com
twitter.com
With a great deal of sadness, we now believe that the game is over. LK99 is NOT a superconductor, not even at room temperatures (or at very low temperatures). It is a very highly resistive poor quality material. Period. No point in fighting with the truth. Data have spoken.
What data?????
Why is not the initial claim a strong statement? And if the strong evidence supplied is the method to reproduce and no one can reproduce, then that should be evidence that their evidence is lacking and therefore their original claim is suspect.
Until someone can reliably reproduce the claims of LK99, it remains speculation.
That's not the way the burden of proof goes! Consider "Fluoride Toothpaste is not a Superconductor".
What you want is conspiracy logic: assume something interesting is probably true based on weak evidence (a handful of videos on twitter seems like table stakes in this particular controversy), and then when people deny it you demand that it "should directly reference strong evidence".
No, the reality is we're not getting reproductions. You're doing the same thing the upthread poster is and demanding that in the absence of evidence, we believe the most interesting assertion. But no, that's not how it works, and that's what the tweet is trying to tell you. It only seems "tone deaf" if you're invested in the argument.
And you're right. But you're not telling us anything about LK-99. If you want to tell me that the linked tweet is a little hyperbolic and could be stated more rigorously, I'd agree! But we both know that's not the frame of the comment I was responding to. The upthread posters "wants to believe", and is looking for reasons to reject the tweet's opinion, not its language.
[1] Which, notably, ignored my toothpaste analogy.
excreteIf you are lucky.
And, you may not have seen it but the account is that of the condensed matter theory center at the university of Maryland. The people working there are at https://www.physics.umd.edu/cmtc/people.html .
https://uk.unofficialbird.com/condensed_the/status/168874791...
They did link the strong evidence upthread:
https://arxiv.org/abs/2308.03110
> To conclude, we have observed a semiconductor-like, non-superconducting electric property in our LK-99-like synthetic samples, along with diamagnetic and soft-ferromagnetic properties arising from supposedly different phases of the mixed product. Our results suggest that one needs to be cautious when interpreting half-levitation observations as evidence for net levitating forces (and, further, as evidence for the Meissner effect). The presence of ferromagnetism in a Pb-Cu-P-O system is somewhat unexpected, as we are not aware of previous reports of materials with related properties. The presence of a flat-bandlike electronic structure in Pb10−xCux(PO4)6O, as revealed in a recent calculation [14, 18], might be able to give rise to such spontaneous ferromagnetism, which warrants further investigation.
So, they replicated the "half levitation" effect and found it had nothing to do with superconductivity. Little chunks of it have ferromagnetic and diamagnetic properties along with it being a semiconductor. Weird, but no evidence at all of superconductivity.
Doesn't explain the videos of fully levitating samples, but those are easily faked and none of them have been very plausible and could just be attention seeking or attempts to manipulate stock markets.
Still should get replicated and those questions that the arxiv preprint raise should really get investigated and answered, but it pretty strongly looks like we're investigating a novel semiconductor now, not a superconductor.
The way this phrase is worded is weird in my opinion. It sounds more like a political statement rather than a scientific one.
https://arxiv.org/pdf/2308.03110.pdf
The twitter account may have had a biased tone because they're actual experts and qualified to have a strong opinion.
Being biased due to ignorance is not a big deal since in principle no one is going to pay you attention anyway.
That doesn't even make any sense to me. Like I don't know what to say because I can't understand what you could possibly be trying to say.
It sounds like you're struggling hard to create a world where experts need to just shut up while ignorant people get to post whatever hottakes they like. That seems to obviously result in a dystopia of information to me.
> Being biased due to ignorance is not a big deal since in principle no one is going to pay you attention anyway.
Well that's clearly false, since we just watched in real time all kinds of strong hottakes from people who had spent the weekend researching superconductors on wikipedia getting wildly upvoted here and on twitter because people wanted to believe.
IMO that is actually bad because that is how you can delude people and how propaganda can manipulate a population.
I never asserted the converse.
Pointing out that strong, biased language can be associated with expertise and therefore in isolation has no bearing on truth, isn't the same as saying that strong, biased language is always associated with expertise.
In fact I just argued that strong, biased language associated with ignorance is generally bad, and is much worse than biased language coming from experts.
> They sprouted the same harsh tone badmouthing video streaming a couple of days ago.
Depending on what they were saying, I might agree with them that they have a point, that statement is rather vague. The video streaming of LK-99 synthesis turned out to be not very useful or enlightening in the end. It settled nothing and created a spectacle--people felt more informed that they could watch it, but at the end of the day they weren't better informed. The preprint from ICQM looks fairly definitive.
But do they claim to be an expert in video streaming? Probably not. Which means how you view their opinions on the two different subjects -- video streaming and superconductivity -- can and should be different.
My gut feel is that such emotionally charged statements are likely inversely correlated with accuracy.
I'm surprised this is the twitter account of a reputable organization.
If it's proven that LK-99 is NOT a superconductor, will still have any "real use"? Or it's going to be completely worthless. Is it "dihcotomic"? Either it's a superconductor and it's helpful for humanity, or it's not and it's completely worthless. Or being "enough" good of a conductor might have applications as well?
Thanks!
Which means it's worthless. Remember, oil was "worthless" too when it was first discovered...
> Enquiring minds want to know: Is diamagnetism not interesting? The answer is that NO, diamagnetism is NOT interesting, many materials (e.g. Pb, Cu, P going into LK99) are diamagnetic. It is a run of the mill property. (There are more results, but CMTC cannot divulge them yet.)
This is in contrast to someone claiming their sample did not exhibit any of the properties of LK-99 at all.
In particular they were needlessly critical of Southeast University before [1], which reported the increasing resistance up to ~230 K, then a sudden drop til ~255 K, then back to the normalish curve. I previously criticised that the purported "zero resistance" below ~110 K is misleading, while I was unsure about the drop, but at least it does show the completely opposite trend to the PKU result and CMTC should have explained (or refuted) this as well.
[1] https://twitter.com/condensed_the/status/1686895266329174016
A lot of the arxiv papers will measure PXRD. Then they will say stuff like "the position of the peaks is almost identical" (https://arxiv.org/pdf/2308.03110.pdf) (emphasis is mine).
Anyone who knows anything about diffraction knows that almost identical means different.
The original paper specified that LK-99 requires a 0.48% contraction of the unit cell volume. if you are off by a small fraction (either from over- or under-doping) the sample is not LK-99. it is something different.
so far all "reproduction" papers have stated that they created the wrong material, then gone on to show that it does not behave as a superconductor.
I'm not saying that LK-99 is definitely a room temperature superconductor, only that I have not seen a single reproduction attempt actually report the same unit cell parameters as reported by the original paper. Thus not a single reproduction attempt has thus far reproduced LK-99.
https://manifold.markets/QuantumObserver/will-the-lk99-room-...
We've seen a lot of miracle cures during the covid-19 epidemic where all the support was a bunch of preprints (and some of the preprints were horrible, I read a few of them to write angry comments in HN).
A paper in a serious peer review journal (if possible/relevant preregistered and with a randomized controlled group) is much better evidence, but it still can be wrong.
https://manifold.markets/QuantumObserver/will-the-lk99-room-...
This other prediction market only gives it a 5% chance of turning out:
https://www.metaculus.com/questions/18090/room-temp-supercon...
IF the game is over, shouldn't arbitrage be possible between these various markets? I guess the timeline is very long for these bets and time is opportunity.
Prediction markets are just uninformed gambling? They don't mean anything if the money is from people with low information? Don't rely on a prediction market to predict validity of a supposed scientific breakthrough?
Why wouldn’t that incentivize someone with high information to come in and make a quick buck?
It's unfortunate that it probably won't work out. But this was fun. Good story, good experience.
Which is indeed down today
Rather than being deflated, I want more of this.
LK99 is more like broad area than very specific substance
https://www.amnh.org/learn-teach/curriculum-collections/cosm...