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A room-temperature superconductor? New developments

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Re: A room-temperature superconductor? New developments

#661

Post by yreg »

montecarl wrote: post #576
badman2001 wrote: post #171

the dft results are definitely interesting, but i note that with the caveat that my background is in experimental condensed matter physics for materials like this and not theoretical, my understanding is that the dominant feature of the conclusions (the flat bands) is a necessary but not sufficient condition for superconductivity in the way the authors describe. again, in experimental condensed matter physics it's ac…

The thing that stands out to me is that the DFT simulations show that the flat bands only occur in a particular crystal structure of the material and it is not the most stable state (at least according to the simulation). This would explain the synthetic challenges involved. These simulations are not perfect, but they can be VERY useful when guided by experiment and when they correlate strongly it is a good sign that…

naive question: if we can simulate this, can't we brute force other superconductors?

Re: A room-temperature superconductor? New developments

#662

Post by whimsicalism »

robot_no_421 wrote: post #647
whimsicalism wrote: post #523

Earlier quoted context omitted.

The difference with the Japan case is that China is going to have a larger base of young, very well educated people than the US for at least the next century unless something changes dramatically with either birth rates or immigration.

China is facing severe demographic issues for the next 20-30 years due to their terribly short sighted one-child policy and their poor immigration rates. Literally the opposite of what you're saying. Where on earth did you get your facts from?

With the population edge they have, they will still have more young people than us. More of their output will have to go for caring for the elderly, but that will scale with technology.

Re: A room-temperature superconductor? New developments

#663

Post by marshray »

Karrot_Kream wrote: post #649
XorNot wrote: post #612

Earlier quoted context omitted.

Superconducting powerlines would be able to transport DC electricity with 0% losses. To put this in context: you could put solar panels in California, and send every watt of power to Alaska or New York, while losing nothing in the transport.

The superconducting effect of LK99 seems to top out at around 150 mA / cm^2. Maybe more research will bear fruit here, but for now we're not looking at HVDC lines.

To my knowledge, that number from the original researchers and no one has yet independently verified it.

External researchers have not even begun to purify and test the limits of this material.

Re: A room-temperature superconductor? New developments

#664

Post by [deleted] »

TillE wrote: post #617
hn_throwaway_99 wrote: post #490

Someone posted this in a comment on another post of LK-99: Wouldn't the first step be verification before replication ? I.e. have the original authors send out some LK-99 samples to other researchers to at least confirm "Yes, this thing is a high temperature superconductor". Wouldn't matter even that much if it were made with unicorn dust: it would be proof that high temperature superconductors are even possible, whi…

Because unless all current replication attempts fail, it would be totally pointless. I know we're all eager for news, but there's no urgent need to verify the claims. That's not how science works. Give it a couple weeks.

[deleted]

Re: A room-temperature superconductor? New developments

#666

Post by fzzzy »

yreg wrote: post #661
montecarl wrote: post #576

Earlier quoted context omitted.

The thing that stands out to me is that the DFT simulations show that the flat bands only occur in a particular crystal structure of the material and it is not the most stable state (at least according to the simulation). This would explain the synthetic challenges involved. These simulations are not perfect, but they can be VERY useful when guided by experiment and when they correlate strongly it is a good sign that…

naive question: if we can simulate this, can't we brute force other superconductors?

Yes, but the search space is mind boggling.

Re: A room-temperature superconductor? New developments

#667

Post by zarzavat »

rvnx wrote: post #308
marshray wrote: post #288

Earlier quoted context omitted.

Over a handheld neodymium magnet. None of the videos have yet shown complete 'levitation', they all have a corner on the surface. But still, not behavior that anyone has ever seen from lead before.

But couldn't it just be a magnet ? I don't understand how it's a proof. You can already do what is in the video (and even better), with for example, pyrolitic carbon ? https://en.wikipedia.org/wiki/Pyrolytic_carbon

Have you seen videos of pyrolytic carbon? A thin sliver of it barely hovers on top of a huge magnet. It doesn’t stand erect. Same effect as LK99 but much smaller magnitude.

Re: A room-temperature superconductor? New developments

#668

Post by jiggawatts »

postmodest wrote: post #645
jiggawatts wrote: post #430

Earlier quoted context omitted.

Is this how the science fiction future we’ve all read in books becomes reality? SpaceX becomes an evil megacorp mining gold from the asteroid belt with LLM AI controlled robot slaves so that we can make hover cars using superconductors?

No no, you use the LLM AI to funnel real people into becoming Belters, then fake their communications back home with those same LLMs, then move your X HQ to Mars and oppress them from there. ...also, Elon would totally pull a Duarte....

Yes, I can see it now. “X corp” is the amalgamation of Twitter, Tesla, and SpaceX. It mines the resources of the outer solar system using enhanced humans (“replicants”). They have Neuralink implants keeping them under the control of their evil overlord: MuskX.

Re: A room-temperature superconductor? New developments

#669

Post by Taniwha »

nwiswell wrote: post #619
fsh wrote: post #516

Earlier quoted context omitted.

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.

> CPU heat output is limited by the resistance of the semiconductors. This is not true anymore. At leading edge process nodes (i.e., smaller conductor pitch), the bulk resistivity of copper changes dramatically because it is increasingly dominated by ballistic electron scattering on the interfaces and grain boundaries: surface area has decreased as a fraction of volume and the average grain size has shrunk to fit ins…

Yes RC wire delays have becoming more important than gate capacitance for a couple of decades now - if R goes to 0 RC delays do too

Re: A room-temperature superconductor? New developments

#670

Post by [deleted] »

cududa wrote: post #340
arcticfox wrote: post #218

Earlier quoted context omitted.

There are a ton of them on Twitter.

Yes and many of them are completely wrong. I keep seeing people saying "CPU's that don't generate heat". How exactly would that work? When a transistor turns off/ switches to 0, where does it dump the electrons? Hint: into heat

[deleted]
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