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LK-99 isn’t a superconductor

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191–200 of 754 posts

Re: LK-99 isn’t a superconductor

#191
post #55

Earlier quoted context omitted.

When are these old days? I remember cold fusion from the late 1980s. There's polywater from the 1960s. N-rays in the 1900s (the first decade) made it to "spiritualists" and "crackpots and extremists" outside of academia, https://archive.org/details/flashofcathodera0000dahl/page/24... . Giovanni Schiaparelli 1877 observation of "canali" on Mars captivated the public.

The Martian canals are interesting misinformation phenomena. A phenomenon that we’ve seen repeated among the woo crowd. Schiaprelli points his telescope at Mars, and sees some faint squiggles. He suspects they’re something dried river beds, and calls them “channels”, like a river channel. Being Italian, he uses the Italian word, “canali”. This word, being the same word used for “canal” in English, gets translated as…

> I don’t think the canal theory ever gained much traction.

I'm not sure what you mean by traction. I wanted to show examples of scientific disagreement which made it to the popular press, to argue that it's been happening for a long time.

Using one of the sources mentioned at https://en.wikipedia.org/wiki/Martian_canals lists several I found this 1902 textbook which suggests it did have traction among astronomers for at least a couple of years, though not general acceptance. Quoting https://archive.org/details/manualofastronom00younrich/page/... :

] These new markings are faint and very difficult to see, and for several years there was a strong suspicion that he was misled by some illusion, — in respect to their "gemination," at least, — which is still ascribed, by some very high authorities, to astigmatism in the eye of the observer or bad focusing of his telescope. Still, the weight of evidence at present favors the reality of the phenomena which Schiaparelli describes. Many observers, both in Europe and the United States, have confirmed his results, and they are now generally accepted, although some of the best, armed with very powerful telescopes, still fail to see the canals as anything but the merest shading

I say "couple of years" because there are several editions of that textbook! In 1904 at https://archive.org/details/atextbookgenera05youngoog/page/3... :

] [Schiaparelli's] observations have since been confirmed and added to by various eminent astronomers in Europe and America, especially by Perrotin at Nice and Lowell in Arizona. But others, equally eminent and apparently under equally favorable conditions, fail to see the reported features.

While in 1888 at https://archive.org/details/textbookofgenera00youn/page/346/...

] "If there is not some fallacy in the observation, the problem as to the nature of these canals, and the cause of their gemination, it is a very important and perplexing one. It is hoped that at the next favorable opposition in 1892 it may find its solution."

Re: LK-99 isn’t a superconductor

#192

One of the good things that came out of this whole story: A very public demonstration, transported through mass and even social media channels, how empiricism and the principle of falsification work, and why they are the only known reliable process for generating knowledge.

The people who made millions off this saw something positive from it.

Re: LK-99 isn’t a superconductor

#193

I don't see how 0.002 ohms per cm could be confused with superconductivity. Is that not orders of magnitude too high? Or there are no instruments which can directly measure resistance more precisely?

Yes, that was my first thought. There are absolutely instruments which can directly measure resistance down to 10E-8 ohms/m or lower, and I would expect any lab doing research into superconductivity to at least have one of those.

Also, "not a superconductor" means that it can't superconduct at any temperature. Where is the evidence of that? Or it's just clickbait?

Re: LK-99 isn’t a superconductor

#194

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.

disagree, the excitement led nowhere. We already have high temp superconductors so even if it was real these applications can/are already handled. Its not harmless either, people invested time, money, and effort.

its great to be excited for real science discoveries but hoaxes are not good, and can potentially cripple, crush the industry thats actually developing these things.

Re: LK-99 isn’t a superconductor

#195

I found Thunderf00t's video on LK-99 to be funny because he pointed out something no one else did: In almost all applications of superconductors, they don't use high-temperature ones for one simple reason: Material properties. Most high-temp superconductors (including LK-99, he was assuming it was one, since he's not qualified to say one way or the other) are a ceramic. The ones that see use in the LHC, for instance,…

Lots of superconductors aren't very good superconductors. They have a low critical magnetic field which limits the current they can carry and the magnetic field they can produce.

The liquid helium cooled niobium-titanium can make strong field and is easy to produce. The RBCOs superconductors, YBCO is the main one, are liquid nitrogen cooled and make even higher magnetic fields. It sounds like it took a while to figure out how make them in bulk.

YBCO superconductors are going to be revolution but will take time for the older systems to disappear. Good example is ITER, which was designed for liquid helium magnets cause nothing else was practical at the time. The SPARC tokamak from MIT uses YBCO magnets which means it can be smaller, higher field, and cheaper cooling.

Re: LK-99 isn’t a superconductor

#196

Earlier quoted context omitted.

So... who cares? Why should laypeople be expected to engage in that much analysis solely to avoid excitement? These aren't policy makers. No lives were lost. Only keystrokes were wasted... and, calling them wasted is probably too harsh. Lots of people learned what a cool thing this would be if it happened, are disappointed that this isn't it, and might even be a little more interested in physics going forward. Why ar…

> This could be a teachable moment that could inform people about climate change, coronavirus and other scientific claims... I addressed why.

Imagining that attention to this somehow displaces attention those things is beyond dubious. You could pick literally any popular topic and level the same exact criticism.

Re: LK-99 isn’t a superconductor

#197
> When copper oxide superconductors were discovered in 1986, researchers leapt to probe their properties. But nearly four decades later, there is still debate over the material’s superconducting mechanism, says Vishik. Efforts to explain LK-99 came readily.

To me, the interesting take-away is that, right at the end. All too often we see peer-review as this slow, inching, excruciating process, particularly in social sciences where it's a de-facto afterthought. It was great to see science chugging ferociously away like a (somewhat!) well-oiled machine, such as the electronic analysis via slightly different methods (e.g. DFT) and the material synthesis efforts by the Argonne NL and Max Planck Institute.

Farewell for now, RTSC.

Side-note: Pure LK-99 is visually beautiful! Who would-a known from those crumbly grey flakes, huh?

Re: LK-99 isn’t a superconductor

#198
post #164
post #135

Earlier quoted context omitted.

I disagree. I get pissed off when revolutionary scientific news is brought to me only to turn out to be some bogus crap. I don’t care about the replication and peer review process, it’s not fun, it’s banal. I would much rather have preferred to learn about LK-99 once it was confirmed to be a room temp superconductor, and if it wasn’t then I’d rather never hear about it. Now I have to walk back explanations I gave to…

It sounds like you were explaining it to people before it was confirmed - why did you do that? I don't really grok the emotional connection you seem to be talking about - how does someone pin their mental state so much on something like this (unconfirmed research)? Is it the idea that there might be something great happening, and that we might get the chance to live in exciting times? I could see people wanting to be…

we already live in exciting times. I wouldnt blame someone for explaining an idea that the scientists themselves came forward and claimed it as a valid result either. Blind optimism is NOT good in my opinion even if intentions are good

Re: LK-99 isn’t a superconductor

#199
post #14

In their preprint, the Korean authors note one particular temperature at which LK-99’s showed a tenfold drop in resistivity, from about 0.02 ohms per centimetre to 0.002 ohms per cm. “They were very precise about it. 104.8ºC,” says Prashant Jain, a chemist at the University of Illinois Urbana–Champaign. “I was like, wait a minute, I know this temperature.” The reaction that synthesizes LK-99 uses an unbalanced recipe…

>“I was like, wait a minute, I know this temperature.” This is an incredibly funny quote out of context, and the absurdity of it betrays an extreme domain expertise.

It's almost like "I know Unix" from Jurassic Park, but not as silly.

Re: LK-99 isn’t a superconductor

#200
post #161

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.

diamagnetic material exist, and no theyre not nearly as useful as a superconductor with 0 resistance.
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