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A room-temperature superconductor? New developments

science.org

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Re: A room-temperature superconductor? New developments

#461

Post by sampo »

irthomasthomas wrote: post #388
dang wrote: post #309

The major threads so far, in reverse order—have I missed any? Huazhong University demonstrates LK-99 diamagnetism - https://news.ycombinator.com/item?id=36953819 - Aug 1, 2023 (265 comments) LK-99 crystal verified to be magnetically levitated (with video) - https://news.ycombinator.com/item?id=36953396 - Aug 1, 2023 (10 comments) Room-Temperature Ambient-Pressure Superconductor LK-99 preprint revision 2 - https://new…

Any idea why the Science article links to a HN post as the source? https://news.ycombinator.com/item?id=36953396 (10 comments)

> the Science article

It's a blog post. Not a Science article.

Re: A room-temperature superconductor? New developments

#462

Post by Melatonic »

ninkendo wrote: post #450
derefr wrote: post #432

Earlier quoted context omitted.

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.

That is.....kind of a huge limitation of the technology lol. Still very cool but less hype

Re: A room-temperature superconductor? New developments

#463

Post by Eduard »

0xDEF wrote: post #260
fallingknife wrote: post #49

Earlier quoted context omitted.

Why are they all from China? Why are they able to replicate so much faster than US labs?

Because there has literally only been 2-3 weekdays since the LK-99 revelation. Do you expect American and European scientists to work during weekends?

I expect plenty of scientists to be excited enough to replicate a potential breakthrough in their labs on a weekend, just as half of HN enjoys experimenting with the latest LLMs over the weekend for fun and curiosity.

Re: A room-temperature superconductor? New developments

#464

Post by missedthecue »

evgen wrote: post #376
whimsicalism wrote: post #344

Earlier quoted context omitted.

China has 1.2 billion people, I feel like it is basically an inevitability at this point.

1.2 billion _old_ people. While quantity has a quality all its own, in this case the demographics are not what you want to see if you are predicting long-term Chinese growth just based on population.

Median age China, 2022: 38.5

Median age USA, 2022: 38.9

Re: A room-temperature superconductor? New developments

#465

Post by S201 »

elfbargpt wrote: post #77
7moritz7 wrote: post #17

Earlier quoted context omitted.

I have seen three now from China alone. Plus a calculation from some respected institute from today that confirms the theory

Throughout this whole saga I've had this feeling that at the very least we can rely on China to really pursue this new development to it's logical end. It's kind of sad, but I don't think I can say the same about the US at this moment. You know for a fact China's going to JUMP on this, figure out if it works or not, and iterate.

Right, because there's surely no scientist in the US interested in pursing something like this as well. Generalize much? Keep riding that "US sucks, China good" train for absolutely no reason.

Re: A room-temperature superconductor? New developments

#466

Post by empath-nirvana »

jtchang wrote: post #418

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…

> Much faster with no heat to burn your lap.

Computation inherently creates heat, that's not something that superconductors will change.

Re: A room-temperature superconductor? New developments

#467

Post by baq »

u320 wrote: post #221
codeulike wrote: post #161

Earlier quoted context omitted.

Would help with fusion, right?

It would make fusion experiments cheaper, but not more successful.

Why not? Higher temperature for magnets means magnets less susceptible to neutron flux right?

Re: A room-temperature superconductor? New developments

#468

Post by dralley »

bluGill wrote: post #410
dralley wrote: post #352

Earlier quoted context omitted.

It's not at all obvious to me that it's more risky than some of the BS that gets hundreds of millions of dollars in VC funding.

Timelines matter. The BS will either return the millions in a couple years or it won't. Basic research may return much more, but your best case is still many years before you gets results. The risk is actually higher with basic research than for BS as well - the pet rock earned money and there are plenty of other examples of stupid things working well quickly. Basic research in fusion hasn't returned anything yet eve…

See, the thing is, you're making an argument about how VC works, and I'm making an argument about allocation of money towards VC vs. other socially beneficial projects.

I understand how VC works. I'm annoyed that - let's even take the Saudis as an example, since they fund half of Silicon Valley anyway - would rather flush their money down the drain on stupid shit than do long-term projects that may help secure their existence post-oil. Even with every motivation to focus on the long-term, still it gets blown on short-term complete garbage.

The rampant short-termism is the real issue

Re: A room-temperature superconductor? New developments

#469

Post by thorncorona »

Melatonic wrote: post #462
ninkendo wrote: post #450

Earlier quoted context omitted.

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.

That is.....kind of a huge limitation of the technology lol. Still very cool but less hype

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.

Re: A room-temperature superconductor? New developments

#470

Post by ChrisClark »

jychang wrote: post #459
baq wrote: post #444

Earlier quoted context omitted.

It’s a zero resistance wire. Build a loop and pump electrons in. Need them back? Connect an off-ramp. There are limits how much you can pump into it, it isn’t magic… but it almost is actually. https://en.m.wikipedia.org/wiki/Superconducting_magnetic_ene...

> Less than 40kJ/L

Pretty sure that includes the volume of the entire cooling system needed to keep it superconducting.
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