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LK-99 isn’t a superconductor

nature.com

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Re: LK-99 isn’t a superconductor

#511

Post by zamadatix »

floxy wrote: post #245
shawabawa3 wrote: post #230

Earlier quoted context omitted.

By that logic we might as well say that wood is a superconductor Nobody has tested it at 0.0000000000000K after all

One group claimed that their sample of LK-99 went superconducting at ~110K: https://arxiv.org/abs/2308.01192

The conclusion is a bit clearer: they think they observed what seemed like zero resistance at the temperature but they are unsure it was actually superconducting, hence the title being the measured resistivity instead of superconductivity directly. It's also possible (and far more likely IMO) them reaching the noise floor of the instrument was not the same as the sample actually having 0 resistance. Superconductors have a sharp dropoff at the critical temperature whereas their sample seemed to just continually have less resistance until the noise floor of the tool.

It'd be cool to find it was superconducting at a temperature near that high though. That'd still be one of the best high temperature superconductors we've found.

Re: LK-99 isn’t a superconductor

#512

Post by chias »

svetb wrote: post #412
drdeca wrote: post #400

Earlier quoted context omitted.

I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the point about "we use less efficient materials for power grid transmission than we could, because of costs". I suppose I didn't expect that we necessarily had like, the "absolute most efficient that could be made" (if that is something substantially more complicat…

Am not the author of that comment, but the fact that comes to mind is that aluminum is used for virtually all transmission and distribution lines - for price reasons - even though copper has better conductivity. If we did discover a room-temperature superconductor, I suspect it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compar…

Silver is even more conductive than copper!

Re: LK-99 isn’t a superconductor

#513

Post by jschveibinz »

imiric wrote: post #448
jschveibinz wrote: post #266

Earlier quoted context omitted.

On the bright side: when people say “believe in the science,” this is exactly what they should be thinking: challenge. This whole process has been super healthy and similar challenges are important and needed for everything published, not just this particular research area. I might be out in left field, but I read so often that researchers are running out of ideas. What’s wrong with getting a PhD for challenging some…

> This whole process has been super healthy Has it, though? The South Korean paper claimed to have found "The First Room-Temperature Ambient-Pressure Superconductor". It took a month for researchers around the world to essentially debunk this. Science works by peer review, yes, but that should have never been a claim to begin with. They were blinded by excitement of the results and eager to publish the paper, instead…

I believe it is the pressure to publish. The number of papers published has grown exponentially and it is reported that the quality of research has decreased.

https://www.researchgate.net/publication/333487946_Over-opti...

https://www.nature.com/articles/533147a

Re: LK-99 isn’t a superconductor

#514

Post by Fatnino »

hunson_abadeer wrote: post #378
thinkingkong wrote: post #2

It’s disappointing news but the excitement and amount of replication on this paper was pretty fun to witness and experience. To me the most interesting part was everyone talking about potential consequences, uses, the order of magnitude improvements we’d see in certain costs or areas. Pumps, MRIs, power grids, chips, etc. Great reminder what materials science can do to some underlying economics.

This is precisely what put me off in these discussions. Not the idea that we might have found a room-temperature superconductor - that part was exciting. It's the part where people confidently talked about its applications without realizing that they probably wouldn't revolutionize CPU performance (Josephson junctions don't seem to work well as non-cryogenic temperatures for reasons unrelated to superconductivity), p…

I think it would make MRI machines cheaper

Re: LK-99 isn’t a superconductor

#515

Post by XorNot »

SamBam wrote: post #506
elihu wrote: post #434

Earlier quoted context omitted.

Aluminum vs copper is a good example. Another is that we already do use superconducting transmission lines in a few places. We could do more of that, but presumably it's expensive to install and/or maintain otherwise we'd be using it everywhere. I'm not sure what the longest or highest capacity superconducting links currently in existence are.

That have to be kept cool with liquid nitrogen, so it would have to be pretty darn short.

Actually no: they have to be insulated well. People forget that it doesn't actually take energy to stay cool, just to remove the heat. The issue is what's your heat gain from insulation inefficiency per length - and it does get better then thicker your cable gets, because volume increases more rapidly then surface area.

Re: LK-99 isn’t a superconductor

#516

Post by seewhydee »

shekispeaks wrote: post #374

They should have also included a quote from CISR an Indian lab that go there about the same time as many of the American labs https://arxiv.org/abs/2308.03544

Yes, I noticed that this article disproportionately quoted American scientists who played relatively minor roles in the replication efforts. I guess the reporter just found it more convenient to reach out to them for comments.

Re: LK-99 isn’t a superconductor

#517

Post by Barrin92 »

godelski wrote: post #171
thinkingkong wrote: post #2

It’s disappointing news but the excitement and amount of replication on this paper was pretty fun to witness and experience. To me the most interesting part was everyone talking about potential consequences, uses, the order of magnitude improvements we’d see in certain costs or areas. Pumps, MRIs, power grids, chips, etc. Great reminder what materials science can do to some underlying economics.

> but the excitement and amount of replication on this paper was pretty fun to witness and experience. I was really elated to see how people were so interested and getting to see what peer review in science actually looks like. How in the real world it is done outside of journals and conferences, which people frequently give the misnomer "peer review." I hope people will walk away from this experience with a better u…

>I hope people will walk away from this experience with a better understanding of how science works

I don't think this was at all what this saga was about. People essentially turned a physics experiment into social media drama and science had nothing to do with it.

I also don't think the 'academic incentrive structure' has fallen out of alignment with the actual goals of science, despite the fact that people keep saying it, and in particular not in condensed matter physics.

If anything this whole thing showed two things: 1. Science works fine, 2. Please keep it to the actual scientists instead of turning it into yet another discipline dragged on Twitter. I know it's an unfashonable thing to say these days, but 99.9% of people have literally nothing to contribute to a debate about bleeding edge physics research, despite that apparenly everyone feels entitled to have an opinion on it.

Re: LK-99 isn’t a superconductor

#518

Post by kibwen »

zmgsabst wrote: post #499
hackerlight wrote: post #457

Earlier quoted context omitted.

Again, this sounds an awful lot like the creationist rhetoric a few decades ago. > "Try challenging evolutionary biology, even in a valid way, and see how popular it is". All crackpots think they're under siege and that their ideas are unfairly dismissed. Their ideas are "valid" (because they say so), so why are those ideas being dismissed without due consideration? You hear the same rhetoric from anti-vaxxers, creat…

Calling groups “crazy” to dismiss their arguments is a classic ad hominem .

At the same time, it's a common mistake to believe that any argument that anyone is capable of making is automatically as valid as any other argument. Some arguments are simply more valid than others; there's no use in humoring people just because they think their unfounded opinion is as valid as any other.

Or maybe I should just defer to how Isaac Asimov put it: "There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.'"

Re: LK-99 isn’t a superconductor

#519

Post by dgoldstein0 »

chias wrote: post #512
svetb wrote: post #412

Earlier quoted context omitted.

Am not the author of that comment, but the fact that comes to mind is that aluminum is used for virtually all transmission and distribution lines - for price reasons - even though copper has better conductivity. If we did discover a room-temperature superconductor, I suspect it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compar…

Silver is even more conductive than copper!

And gold too.

Very expensive to build anything sizable out of it

Re: LK-99 isn’t a superconductor

#520

Post by xtracto »

seewhydee wrote: post #510
gfodor wrote: post #297

The substance produced from the paper isn't a superconductor. While extremely unlikely, there is still a chance that LK-99 is a superconductor, but the paper itself did not sufficiently describe the method needed to make it so as to replicate it properly. We will know the resolution to this once the sample from the original researchers is assessed by a third party, of which there are presently at least two to my unde…

The thing is that there are now multiple independent lines of investigation pointing to LK-99 not being a superconductor, and explaining away the original "smoking guns" offered by the authors. It's like we have a murder suspect, the murder weapon, and fingerprints lifted from the scene. At this point it could still be space aliens, but nobody in their right mind would treat that possibility seriously.

You almost described the reaction of the "tech bros" when the Reiser murder happened: The number of gymnastics some people went through to justify Hans' actions(removing a seat in his car, buying books about crime investigation, blood on the car, etc, etc.) was comical.
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