Hacker News Reader

Comment by gwern | Hacker News Reader

This is LK-99 derived? Now I'm even less interested. Because if you believe this one, you need to believe that despite LK-99 being bogus, that somehow, trying to make a new LK-99 variant was lucky enough to find the one compound out of countless attempts that winds up working - as opposed to coming out of a completely different, still viable, line of research. Stranger things have happened in the history of science & technology... but not that many.

View on HN

This would be a difficult to believe coincidence if diamagnetism and superconductivity were unrelated physical properties, but they are not.

The hard part is that people have already tried really hard to make and measure a superconductor in the LK-99 system, and these researchers have once again gotten close, but not succeeded. There is some precedent for this: one of the highest-temperature superconductors is two-dimensional iron selenide supported on strontium titanate, which superconducts at 100 K, while the bulk iron selenide superconductivity is a measly 8 K at normal pressure (38 K under pressure). At this point, the most plausible way that superconductivity could be occurring in the LK-99 system is if it's in a metastable or nanostructured (possibly two-dimensional) phase that doesn't like to or can't exist as a uniform bulk material.

That scenario, if true, would surpass any other in the history of science. It's akin to the Monty Hall problem, but with a trillion doors, where you don't change your choice after all but two are shown not to have the superconductor.

So obviously if true there's a better explanation of why those early experiments failed.

did you catch the part about sulfur?

i.e. LK-99 w/ sulfur contamination was originally blamed for the magnetism. This new variant is explicitly sulfur-based.

Yes this is LK-99 derived. (See the paper's reference 4 and 5.) Eh, of course it is unlikely LK-99 is bogus and this one is not, but then the correct conclusion to draw is that LK-99 is not bogus?

Perhaps LK-99 is bogus, and they were triying to reproduce the result, they failed succesfully and they got another similar compound that is not bogus.

That’s possible but far less likely than the alternative explanation that either this is bunk too or LK-99 contained signal that people dismissed due to a hole in our methodology.

Wait how are all the flaws in the paper and all the failed reproductions of LK-99 and all the signs that LK-99 is just diamagnetism compatible with LK-99 being a proper superconductor?

The thing is.... all the failed reproductions of LK-99 were based on the leaked version of the paper, which according to the authors is missing some information/steps for production. They said they would publish the complete/final version of the paper in 2024, waiting to see that.

I stop at "lead apatite" and immediately lose intrest when reading these articles.

Reply on news.ycombinator.com