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2bitencryption | 2 years ago
Are the superconductivity properties "all or nothing"? Meaning, if you get the synthesis wrong of the material, would you expect it to be "kind of" superconductive? (I guess, a very low, but non-0, resistance)?
Or is it something where it has normal resistance in all cases unless you get it just right, and then it becomes superconducting?
One more question - in physics, it seems like something having a value "0" is never really possible. Like, you can have something with low friction, but not zero friction. We pretend things have zero friction for high school physics problems, but they don't really. Is superconductivity like that? Is it actually, genuinely, exactly 0.0000(...)? Or is it just very close to zero, so close that it can behave like something with zero resistance (but in reality it's resistive, but just barely)?
sbierwagen|2 years ago
The thing that prevent infinities showing up, or letting us pour gigawatts of power into a single superconducting magnet until it turns into a black hole is that superconductors have a "critical current" over which it falls out of the superconducting state. (At which point it enters the normal, resistive state, suddenly becomes very hot, and boils off all your very expensive liquid helium, a "magnet quench" https://en.wikipedia.org/wiki/Superconducting_magnet#Magnet_... )
LK-99's published critical current is actually quite low, maybe because of sample purity issues. Hopefully it can be improved, otherwise we might be in the comical situation where room temperature superconductors exist and can be used but the cables end up being too thick and can't compete economically with copper.
tetha|2 years ago
This would btw be similar to a proof of P = NP, including the caveat that the best-case runtime of an NP-hard problem is a polynomial of degree 40000. It'd be polynomial runtime, but very much in the "ouch" and "infeasible" territory.