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Ferromagnetic half levitation of LK-99-like synthetic samples

arxiv.org

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Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#131

Post by threeseed »

yongjik wrote: post #116
jgtrosh wrote: post #23

Earlier quoted context omitted.

According to Wikipedia: > On 3 August 2023, the Korean LK-99 Verification Committee requested a high-quality sample from the original research team. However, the team responded that they would only provide the sample once the review process of their paper, potentially submitted to APL Materials, is completed. This process is expected to take several weeks or months.

From what I've heard, the chief of the Korean Society of Superconductivity and Cryogenics had personally called LK-99 out as a hoax - which might have been justifiable, given evidences, but it might explain the reluctance by the LK-99 team. (Assuming the inventors of LK-99 believe it's real, they could be thinking "Why should I give you the honor of being the first outsider to verify the sample, when we could ask any…

I think we should be careful to throw provocative words like hoax around.

There is no official statement from Korean Society of Superconductivity and Cryogenics saying it is a hoax only that they are still waiting for a sample from the original scientists.

At this point we don't know (a) whether LK-99 is a RT superconductor and if it isn't (b) whether it was simply an error in their research or a conspiracy amongst the scientists to commit fraud. Until we definitively know both I don't see why people should be slandered.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#132

Post by ironborn123 »

versteegen wrote: post #95

Very interesting comments on the paper by Prof. Michael S. Fuhrer https://nitter.net/i/status/1688755932275384320 > But I think they buried the lede a little. Ferromagnetism is novel and unexpected in this material system, and might be interesting. But strong diamagnetism even more so > Even if the diamagnetic fraction is the entire sample (appears less) then it would be the second-strongest diamagnet known (and pyro…

There are 2 things in favor of the Korean team

- Hyun-Tak Kim is unlikely to ruin his career and legacy for something careless and frivolous. But stranger things have happened, so lets assign a 10% probability to give some benefit of doubt to the team.

- The various DFT papers show interesting flat band structures. But DFT is an approximation and also they do not take into account electron electron correlations. So lets assign another 10% probability for this support.

This crude estimate would give a 20% chance of RTSC. Rest has to be resolved by actual demonstrations, primarily from the Korean team themselves, and then from reputed Western researchers/labs.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#133

Post by jossclimb »

versteegen wrote: post #95

Very interesting comments on the paper by Prof. Michael S. Fuhrer https://nitter.net/i/status/1688755932275384320 > But I think they buried the lede a little. Ferromagnetism is novel and unexpected in this material system, and might be interesting. But strong diamagnetism even more so > Even if the diamagnetic fraction is the entire sample (appears less) then it would be the second-strongest diamagnet known (and pyro…

Coincidently this is the first time of hearing of nitter.net, do I need to open an account there too?

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#134

Post by InvisibleUp »

jossclimb wrote: post #133
versteegen wrote: post #95

Very interesting comments on the paper by Prof. Michael S. Fuhrer https://nitter.net/i/status/1688755932275384320 > But I think they buried the lede a little. Ferromagnetism is novel and unexpected in this material system, and might be interesting. But strong diamagnetism even more so > Even if the diamagnetic fraction is the entire sample (appears less) then it would be the second-strongest diamagnet known (and pyro…

Coincidently this is the first time of hearing of nitter.net, do I need to open an account there too?

It's just a read-only Twitter mirror.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#135

Post by fnordpiglet »

versteegen wrote: post #113
fnordpiglet wrote: post #97

Earlier quoted context omitted.

You’re reading something entirely different - at the end of a long discussion of sending the samples off for more testing, holding hope it’s a SC but admitting it’s always been a long shot, he notes at the end: > That said, I think we're getting to the point where magnetic observations may be adding more noise than signal. Yesterday, I did perform the pole flip that was discussed in the last video. Very important to…

He wrote that other tweet before that paper was put up on arXiv. How does the fact that the one I linked to is a reply to the one you quoted change the plain meaning of his words? I'm trying to understand how I've misinterpreted his tweet but I've got to interpret "Sounds like it explains everything we're seeing" as referring to his own observations too, not (just) other people's. He's been looking for an explanation…

My bad, my reader view cut the tweet off and just showed the original.

Still, his phrasing doesn’t indicate it’s over for him, just bordering - perhaps explains everything they’re seeing, but it’s :

* not LK99

* a conjecture

* isolated to magnetic properties that are acknowledged to be novel and don’t rule out messier effect

* ignore other claimed properties like resistivity

Also, something explaining everything you are seeing is again a demonstration of an alternative, as is evinced by the material not being LK99, that claimed LK99 as a ceramic without a reliable method of production with a claimed low production rate (less than 10% of runs claimed by the original authors, with them claiming to have done over 1000 runs to produce their sample).

Again: I think it’s time for science to take the helm and hottakes to take a back seat for a while. I expect we will have something noteworthy either way by the end of the year. By the end of the month conclusions are fun gimmicks. I’m down with fun and love a good gimmick, but I’ll withhold belief in either direction until the original teams paper is released, their claimed sample is analyzed independently, more details of the claimed process are released to allow replication, and any novel properties have a stronger theoretical explanation. It’s extraordinarily unlikely they have found a room temperature super conductors, but not impossible. Regardless, they’ve discovered something novel and that, by definition to any scientist, is interesting.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#136

Post by herewulf »

InvisibleUp wrote: post #134
jossclimb wrote: post #133

Earlier quoted context omitted.

Coincidently this is the first time of hearing of nitter.net, do I need to open an account there too?

It's just a read-only Twitter mirror.

It "just" makes Twitter readable to the Internet at large.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#137

Post by lifthrasiir »

threeseed wrote: post #131
yongjik wrote: post #116

Earlier quoted context omitted.

From what I've heard, the chief of the Korean Society of Superconductivity and Cryogenics had personally called LK-99 out as a hoax - which might have been justifiable, given evidences, but it might explain the reluctance by the LK-99 team. (Assuming the inventors of LK-99 believe it's real, they could be thinking "Why should I give you the honor of being the first outsider to verify the sample, when we could ask any…

I think we should be careful to throw provocative words like hoax around. There is no official statement from Korean Society of Superconductivity and Cryogenics saying it is a hoax only that they are still waiting for a sample from the original scientists. At this point we don't know (a) whether LK-99 is a RT superconductor and if it isn't (b) whether it was simply an error in their research or a conspiracy amongst t…

There were a couple of unofficial statements from the Chair of KSSC though. He is now known as the "Mr. Bahahaha" in the Korean internet because he initially dismissed a mail from Q-Center wrongly sent to him by starting his Facebook post---now removed---with "Bahahaha, the era of room-temperature superconductivity is here. Ambient pressure too! Shouldn't my fortune get better?" (translation mine).

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#138

Post by influxmoment »

throw-7462637 wrote: post #123
rurban wrote: post #77

Earlier quoted context omitted.

If you cite Korean (or Chinese or Japanese) names, please write them correct. There is no Hyun-Tak Kim, he is called Kim Hyun-Tak. Likewise Kwon Young-Wan. In Korean it's trivial to detect, in Chinese not so, in Japanese very hard.

Ouch. This comment backfired quite badly. Turns out the person being replied to is Korean, the commenter is likely not, and in addition this is how the authors wrote their names themselves. Yet I do not wish this comment to be snarky. I’m interested in the broader perspective (and I apologize in advance to the parent for using this as an hook). The comment seems common of the present era in which polarization (leadin…

Seeing mistakes about Korean names in the media is very common. It's a lost cause at this point

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#139

Post by chmod600 »

p-e-w wrote: post #125
segfaultbuserr wrote: post #106

Earlier quoted context omitted.

A magnetic levitation demo indicates a possible Meissner effect (which is refuted here by this paper), and this is so much easier than a resistance measurement, which is a delicate task and susceptible to experimental errors. So levitation is used as a quick "first check", especially when you don't have a full lab setup to do other tests, which are much more complicated (in addition to a levitation test or a resistan…

> One cannot measure superconductivity with an ordinary ohmmeter. But one can measure electrical resistivity, and if the material's resistivity is much lower than that of ordinary materials, that would be super interesting and valuable, regardless of whether it is a "true" superconductor or not. If this relatively cheap material had a resistivity around 1/100th that of copper, that would be an engineering breakthroug…

I think you are missing the point: a typical ohmmeter would have metal probes, so with a superconductor you would just be measuring the resistance of those probes. Any attempt to overcome that problem probably introduces a lot of chances for error or noise, or require some huge sample of the superconductor.

Re: Ferromagnetic half levitation of LK-99-like synthetic samples

#140

Post by Firmwarrior »

clmay wrote: post #112
tkzed49 wrote: post #108

Earlier quoted context omitted.

It could be the sheer volume of discussion. I've seen a lot of these posts and this is the first time I've read this question.

Maybe it's because I have been obsessively ensuring that I read every comment on every top thread... Some kind of selection bias could be at play...

The top comment on every thread about every new thing on HackerNews is a half-assed debunking of it
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