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Superconductor news: What’s claimed, and how strong the evidence seems to be

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Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#131

Post by hughw »

mthomasmw wrote: post #88
local_issues wrote: post #78

Earlier quoted context omitted.

Ding ding ding! We still don't know how bikes work, we have a pretty good but incomplete model for lift on airplanes, and no one has the faintest why Tylenol works. We should figure that out! But we can definitely keep using all the applications until then. (Except for Tylenol, we keep learning how bad that stuff is) EDIT: It won't let me post more, so here's the answers to responses. For sure! https://www.cbc.ca/new…

Do you have a link handy for "we don't know how bikes work" ?

e.g. What keeps bicycles balanced with or without a rider is still an active area of research, and even the seemingly basic idea that, for a bicycle to be self-stable, it needs to turn the handlebars into the fall, has not yet been proven.

[*]https://ciechanow.ski/bicycle/

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#132

Post by petsfed »

rsfern wrote: post #102
petsfed wrote: post #63

Earlier quoted context omitted.

Based on what I'm hearing, it sounds like they weren't able to produce a macroscopic ingot of the stuff, so it seems likely to me that the superconducting part is up at the end there. However, without further explanation, I'm disinclined to take that video (fantastic as it seems) to be conclusive evidence of anything.

The original preprint mentions bulk samples, but I’m not sure what size they were. I would guess at least a few millimeters scale, but really bulk just mostly means “not a thin film”

As an undergrad I helped with research on quasars, where reasonable precision was solar mass orders of magnitude and tens of parsecs, and the periodic table was Hydrogen, Helium, and "metals". Then I switched to condensed matter physics for grad school, where "bulk" meant "a scale visible to the naked eye under very good conditions".

The dichotomy makes me laugh.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#133

Post by chasd00 »

dougmwne wrote: post #60
carabiner wrote: post #32

Earlier quoted context omitted.

I'd bet the country would be transformed by this. SK universities (SNU, KAIST) would rocket in reputation for solid state physics research. Massive money inflows to the country from production of the material. Deep down I think most of us realize that this will probably turn out to be nothing.

It’s nothing unless it turns out to be something. I’ll draw an analogy to the LLMs and diffusion models that have lately rocked the computer world. These things are straight up science fiction. I would have said computers would have never been capable of art and poetry. It was all fantasy until it was suddenly reality. We’ll probably know if this can be replicated relatively soon. And if it can it will kick off a who…

Dude I’m right there with you, fingers crossed!

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#134

Post by tamimio »

jonplackett wrote: post #11

If this material does just what they say it does, what would it revolutionise? Or as the article talks about, is this just a pointer at other possibilities that would be the real game changers?

I would build a drone that levitates indefinitely.. for a starter.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#135

Post by btilly »

WaffleIronMaker wrote: post #112
carabiner wrote: post #92

Researcher on reddit thinks it's probably spurious measurement artifacts, not superconductivity: > I would say they are not faking it, but instead they just don’t understand what they are looking at. Based on what measurements they are doing, as well as how they are doing them, they do not have a good understanding of the standard processes to characterise a superconductor. Also, based on their analysis/discussion, t…

Another interesting analysis from that post: > So, to clarify for my nonexpert brain, if this were a superconductor and their measurements were accurate: > Fig 5 means the sample must be completely pure to be a superconductor > The rest of the paper indicates the sample must have impurities. > So it's pretty safe to say that either it's not a superconductor or their measurements are wrong (or most likely both). Since…

The paper that I'm seeing only has 4 figures.

In any case, the need for impurities would not itself surprise. Having controlled amounts of impurities is called "doping", it is well-known from studying semiconductors and other high temperature superconductors that the amount of doping can have a huge impact on a substance's properties.

See https://physicsworld.com/a/the-ups-and-downs-of-doping/ for verification of this point.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#136

Post by gus_massa »

mrguyorama wrote: post #108
Analemma_ wrote: post #84

Earlier quoted context omitted.

Room-temperature superconductors have so many urgent commercial uses that if this fake, I doubt the error will persist for that long. There's too much at stake.

There's also probably a hundred labs skipping over replication completely to try and beat someone else out on a random permutation of these materials and methods and hoping to get lucky.

Yes, "replication" in this experiments usualy means foloeing the oficial recipe and many small variants.

Publishing an exact reproduction is difficult, but a new record a few degrees hotter is easy. (And even another variant with a lower temperature and more tolerance for current or magnetic field can be published with the right text.)

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#137

Post by tux3 »

New scientist got a reply from the authors and a few other experts: https://www.newscientist.com/article/2384782-room-temperatur...

>Kim has only co-authored one of the arXiv papers, while the other is authored by his colleagues at the Quantum Energy Research Centre in South Korea, some of whom also applied for a patent on LK-99 in August 2022.

>Both papers present similar measurements, however Kim says that the second paper contains “many defects” and was uploaded to arXiv without his permission. In that paper, the work is described as opening a “new era for humankind”.

>Other experts that New Scientist consulted were similarly sceptical about the results and the data produced. Some raised concern that some of the results could be explained by errors in experimental procedure combined with imperfections in the LK-99 sample.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#138

Post by dtgriscom »

curiousObject wrote: post #36

While we’re waiting for experimenters to reproduce this, it’s worth comparing this amazing announcement to the Cold Fusion affair of 1989[1] It’s notable that the first publications about attempts to reproduce the Cold Fusion experiment all reported positive results. It’s probably because experimenters who got negative results decided they might have done something wrong so they kept trying, and delayed, and they did…

I miss Cold Fusion. What a wonderful idea. It's a shame reality didn't cooperate.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#139

Post by willis936 »

whatshisface wrote: post #119
macromaniac wrote: post #117

Earlier quoted context omitted.

He doesn't provide an actual counterargument,he just says he doesn't like the data without explaining why. His earlier comment that graphite can do the same thing is untrue afaict. Graphite can repel the magnetic field but it would slide off, this is why in diamagnetic experiments multiple magnets are used to keep it in place. In the video it doesnt seem to be sliding anywhere, so imo the video is not showing diamagn…

It is clearly resting on the magnet. I don't know the mechanics off the top of my head, but that is enough mechanical constraint for a pair of permanent magnets to levitate.

It isn't. Permanent magnets would be unstable. This would have to be a diamagnetic or superconducting material.

Re: Superconductor news: What’s claimed, and how strong the evidence seems to be

#140

Post by tux3 »

btilly wrote: post #135
WaffleIronMaker wrote: post #112

Earlier quoted context omitted.

Another interesting analysis from that post: > So, to clarify for my nonexpert brain, if this were a superconductor and their measurements were accurate: > Fig 5 means the sample must be completely pure to be a superconductor > The rest of the paper indicates the sample must have impurities. > So it's pretty safe to say that either it's not a superconductor or their measurements are wrong (or most likely both). Since…

The paper that I'm seeing only has 4 figures. In any case, the need for impurities would not itself surprise. Having controlled amounts of impurities is called "doping", it is well-known from studying semiconductors and other high temperature superconductors that the amount of doping can have a huge impact on a substance's properties. See https://physicsworld.com/a/the-ups-and-downs-of-doping/ for verification of thi…

This is the second, slightly cleaner paper with more figures: https://arxiv.org/ftp/arxiv/papers/2307/2307.12037.pdf
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