Currently they're only feasible as high quality power sources for fabs and other industrial uses because of the operating costs of cooling the superconductors.
All the smart people in the US work in tech and finance. If you have a big ole' brain, why would you take $80k to work in some crumby lab when you can get paid $350k to maintain a login screen from the comfort of your mountain side home.
Because “smart” and “monomaniacally focused on financial gain” are two separate things?
What is monomaniacally focused about maintaining a login page for $350k?
The ramifications of the inflection point we are currently at is mind boggling. I had a hard time explaining this last night but we may very well be witnessing the beginnings of a technological transformation era much like when the p-n junction was invented. From the 1940s standpoint it would be hard to envision all we had today. - Lossless transport of energy - Batteries that don't take any time to recharge - Faster…
None of the things you listed are limited by the conductors in them. The efficiency of high voltage AC power lines is limited by capacitive coupling to ground. Battery charging is limited by the cell chemistry. CPU heat output is limited by the resistance of the semiconductors. Turns out metals (in particular copper) are already incredibly good conductors.
> Battery charging is limited by the cell chemistry. Yes, but superconductors don't have that limitation, do they? You just dump current into them.
They have low losses when storing power, but power has to be stored in the magnetic field. They have a limit on acceptable magnetic field strength called the critical field though, above which it stops being a superconductor and bad things™ happen. Current SMES systems have an energy density of about ¹⁄₅₀th of current Li-ion batteries.
I believe the implication is that LK-99 is basically a demonstration of an entire class of materials which should have room-temp superconduction properties. IE we can enumerate through the entire class and find the ones with the properties we want.
There is no reason to assume that even if it's real. In fact, the tight tolerances of this seem to indicate the opposite.
At least according to this wikipedia chart on superconductor discovery timelines[1], it seems like most discoveries aren't one-off.
> Batteries that don't take any time to recharge Huh? Is this actually a thing that this enables? I don't initially see how
Resistance is what makes things hot, and heat is what makes dumping huge amounts of charge current into batteries a bad idea. No resistance → no heat → no need to charge with low current†. Another way to say it is that, with a superconducting wire, you can make the wire as thin as you want and still pass the same amount of current through it, without melting the wire. Picture using a USB-C cable to charge your car. †…
There are many things that seem like electrical resistance but are different phenomena. Capacitive reactance, inductance, "radiation resistance", etc. Superconductors don't prevent any of these effects. But, these effects are usually smaller than ordinary resistance.
Resistance is what makes things hot, and heat is what makes dumping huge amounts of charge current into batteries a bad idea. No resistance → no heat → no need to charge with low current†. Another way to say it is that, with a superconducting wire, you can make the wire as thin as you want and still pass the same amount of current through it, without melting the wire. Picture using a USB-C cable to charge your car. †…
I’m not an expert on this, but I think superconducting wires have an current limit, as a current flowing creates a magnetic field which the superconductor has to repel. I read that the paper states a very low current limit for LK-99, meaning it loses superconductivity once a very modest amount of current is passed through it.
It's hard to tell what the critical current density of LK-99 is, because their sample is porous and probably very impure. They measured the critical current they could pass through a sample, but the conducting cross-section is somewhat unknown. Its high critical temperature suggests that it should probably have a higher current capacity than other superconductors. That said, in the extremes, current density is also limited by tensile strength, because electromagnetic coils repel themselves.
The US' stated policy is global freedom of navigation and that has been the primary policy aim that they enforce since UNCLOS in 1982. So no, they do not control access to the oceans.
