>Assuming this is all true, why is it just now coming to light? Did they just not know what they had? This is why the calculations by Sinéad Griffin looked so

>Assuming this is all true, why is it just now coming to light? Did they just not know what they had? This is why the calculations by Sinéad Griffin looked so interesting to me: they suggest that the superconductivity depends on an unconventional substitution pattern that might not (in fact should not) occur in most samples of Cu-doped lead apatite. So the active structure was only present in tiny quantities, requiring a long period of trial-and-error optimization. Again, this is far from proof, but I thought it was at least very curious to have some theory that explains not just a mechanism for superconductivity but also why the samples seem to teeter on the edge of superconductivity so frustratingly. The replies to my previous post ( https://news.ycombinator.com/item?id=36958419 https://news.ycombinator.com/item?id=36958419 ) suggesting that flat bands appear simply because copper doesn't belong in that lattice seem inconsistent with the fact that a flat band was not observed when copper substituted at the wrong type of lattice site. If flat bands appear merely because of the unpaired copper electron, they should appear when it is substituted only at Pb {2} sites, but they don't. The appearance of this band structure plus the observance of diamagnetism just takes us from happenstance to coincidence, so we need one more to conclude it is enemy action. FWIW I don't work in condensed matter physics but I have taken the classes at grad level a few years back. I also should really be doing other things, but this is probably the most fun scientific news cycle since 'Oumuamua at least. (COVID doesn't count as "fun".)