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LK-99 isn’t a superconductor

nature.com

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Re: LK-99 isn’t a superconductor

#361

Post by kergonath »

baby wrote: post #125
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.

+1. I’m wondering how many people will become physicist due to this wave of exciting news :) we’re not getting superconductors today, but we might get less “oh my god the earth is doomed humans are horrible” and more “I’m optimistic about the future of the human race”

As a practising material physicist, I am very enthusiastic about the progress of knowledge in my field and human curiosity and ingenuity, and also very pessimistic about the outlook for our various civilisations and appalled by human carelessness, shortsightedness, and selfishness.

My long term pessimism comes partly from the fact that I know what is behind the magical technologies that are supposed to save us, which is why I am very skeptical about them. I am also very doubtful about our ability to make the right decisions in difficult times and under severe constraints. But hey, I do have a cool, interesting, and enjoyable job.

Re: LK-99 isn’t a superconductor

#362

Post by eutropia »

> Separated from impurities, LK-99 is not a superconductor, but an insulator with a resistance in the millions of ohms — too high to run a standard conductivity test.

Not quite a superinsulator, but ironic.

Re: LK-99 isn’t a superconductor

#363

Post by OJFord »

EvgeniyZh wrote: post #158
tareqak wrote: post #8

Earlier quoted context omitted.

Perhaps scientists will create a checklist for performing experiments on potential superconductive materials with caveats and gotchas. A team going down the checklist would either demonstrate one of 1. They performed the step in the checklist and provide the corresponding sufficient/exhaustive evidence of having done so. 2. An explanation as to why that step is not applicable allowing them to skip said step. An after…

1. Check that it actually superconducts

That's not trivial, because if it's known to be impure then you expect some resistance in your measurement, you already know it won't be 0R. And if you think it is pure and superconducting then how low does your test equipment go anyway?

I'm not an expert in the field at all, but aiui that's why they would have been looking at what seem like roundabout tests etc. that don't seem like they're actually addressing what's interesting.

Re: LK-99 isn’t a superconductor

#364

Post by [deleted] »

[deleted] wrote: post #356
dralley wrote: post #41

Honestly, I feel bad for the original authors, who were correctly holding out for stronger evidence but were forced into publishing early by the actions of a third party going behind their backs. I hope they don't experience undue blowback because of this.

[deleted]

[deleted]

Re: LK-99 isn’t a superconductor

#365

Post by [deleted] »

pistachiopro wrote: post #257

You can publish an article with a title like this and probably not end up embarrassed. Room temperature and pressure super conductors seem hard enough to find that chances are any given paper claiming to have found one will end up with a more mundane explanation. And I do think the information about the phase change of Cu2S is highly relevant, as it points at a way the original researches my have fooled themselves. T…

[deleted]

Re: LK-99 isn’t a superconductor

#368

Post by kergonath »

dheera wrote: post #161
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.

> were responsible for the sharp drops in electrical resistivity and partial levitation over a magnet Are these properties still useful? If something can levitate without being a superconductor it is already useful for a LOT of things.

> If something can levitate without being a superconductor it is already useful for a LOT of things.

It is not that useful. Electromagnets are used when we need something like that at scale, such as in maglev trains. Permanent magnets have their uses, but we have plenty of others that are as strong as this, and plenty of others that are much stronger than this. I suppose we will investigate it’s properties and we might find something interesting, but almost certainly not because of its magnetic properties.

Re: LK-99 isn’t a superconductor

#369

Post by kergonath »

hgsgm wrote: post #269
dheera wrote: post #216

Earlier quoted context omitted.

Diamagnetic levitation is extremely weak, which makes it much less practically useful, and also reduces its entertainment value (if you can levitate things 2 cm above the surface the 2 billion children in the world will be all over the stuff; the 1-2 mm you can get with bismuth diamagnetism isn't particularly impressive.

I don't know all these subtleties, but maglev trains are awesome.

Maglev trains do not use diamagnetism or this kind of permanent magnets. They use electromagnets and sometimes much stronger rare-earth magnets, which are much more convenient and effective. Some of them do use superconductors, though, AFAIK.

Re: LK-99 isn’t a superconductor

#370

Post by beders »

Well, maybe this is the beginning of another cold fusion story.

Despite failures to reproduce the Pons/Fleischmann results, it spawned a whole new field: LENR which has very interesting yearly conferences.

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