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Electronic Structure of LK-99

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Re: Electronic Structure of LK-99

#371

Post by yreg »

lucideer wrote: post #362
yreg wrote: post #328

Earlier quoted context omitted.

Could we please stop giving attention to the obnoxious anonymous Russian troll who's only proof is a photo of a spec of dust in a syringe, who says she 'didnt follow the paper beause she immediately invented a better way to make a room temp superconductor', who says she 'doesnt care about superconductors' and keeps tweeting USSR propaganda? I really don't get how she keeps getting recommended in these hacker news thr…

Not sure if you're implying she's cooked up a few crucibles at home purely for internet attention (nor what the relevance of her political views are here), but regardless the thread is interesting either way as it's generating lot of general interest in replication. This is perhaps a better link: https://eirifu.wordpress.com/2023/07/30/lk-99-superconductor...

One doesn't need to cook several crucibles to create the photos that were posted.

The views are relevant because you are directing people to that account.

What exactly is interesting in that thread? It's just cringe talk about 'weapons grade autism' unless I'm missing something.

Re: Electronic Structure of LK-99

#372

Post by u320 »

marcosdumay wrote: post #369
itsoktocry wrote: post #318

Earlier quoted context omitted.

"1970: Superconducting trains to go from New York to LA in 20 minutes!" 50+ years later the US has how many high speed trains, of any kind?

I guess that's partially missing the point. The main benefit of a superconducting maglev is that it's cheaper to build than a on-rails high-speed train. Specially on problematic terrain (what I understand includes every possible East/West route on the US).

Why would it be cheaper? The actual rails is a pretty small part of constructing high speed rail, isn't it? Especially on problematic terrain.

Re: Electronic Structure of LK-99

#374

Post by cyberax »

MrBuddyCasino wrote: post #267
bluecoconut wrote: post #12

I got my PhD studying band structure of high-tc superconductors (experimentalist, ARPES). These Cu d-d interactions right at the fermi energy give me huge hope. Feels very familiar to other superconductors (re: all the cuprates). (Note: I specifically worked in a lab that was measuring a lot of the d-wave character / gap-energies of various superconductors) All in all, I'm now much more bullish on LK-99 being real su…

This is probably the most stupid question to ask, but while were are still trying to confirm superconductivity instead of understanding its precise mechanism of operation, why the focus on levitation on band structure to confirm the news instead of just "yep this chunk has actually zero Ohms"?

Build a loop out of a superconductor, induce a current in it, and then measure the resulting magnetic field after a couple of minutes.

If the field is still there, then you have a superconductor.

Re: Electronic Structure of LK-99

#375

Post by audunw »

deelowe wrote: post #347
PuffinBlue wrote: post #306

Earlier quoted context omitted.

Regarding fusion - have you seen Helion’s approach? [0] It seems their approach removes many of the issues with Tokamak or Laser Pulsed fusion. It also reduces most of the feedstock issues with the two part fuel breeding approach. Their approach seems easier to be optimistic about. [0] https://youtu.be/_bDXXWQxK38

https://www.youtube.com/watch?v=3vUPhsFoniw Be careful with real engineering. Many speculate he's doing paid content between this and spinlaunch.

While it’s always good to be a bit skeptic, don’t take this video at face value either. I’d argue that it has bigger issues than Real Engineerings video because it tries to come off as scientifically accurate, but may actually be deeply flawed. See comments on this Reddit post for some deep discussion: https://www.reddit.com/r/fusion/comments/10g95m9/comment/j67...

Real Engineering has a tone where - while I do think they usually keep a high standard - I don’t assume that they’re necessarily 100% correct or that the new technology they cover is necessarily viable. With both Spinlaunch and Helion I just came out of it with the feeling “cool, interesting, looks promising”

Re: Electronic Structure of LK-99

#376

Post by marcosdumay »

taneq wrote: post #303
feoren wrote: post #276

Earlier quoted context omitted.

From my perspective, LK-99 is by far the most likely to be an actual serious technological breakthrough. If it's real, it would be a breakthrough on the level of the discovery of electricity, the lens, the transistor, or the laser. One of those era-defining bottlenecks in the Civilization technology tree. GPT-4 is a nice iterative improvement over previous work, and a culmination of decades of research. It's not anyw…

> close to the limit of what we can accomplish with our current understanding of AI and our current availability of good data Isn't this literally the definition of 'state of the art'? It's the best we can do with our current understanding and data. This doesn't seem like a convincing argument that current ML techniques are tapped out.

No, what the GP is claiming is a theoretical end of line, where we would need some very innovative breakthrough to go further.

Those tend to happen decades apart in a single field. And often the breakthroughs even come before the end of line does, so we jump a few decades.

Now, the GP didn't put out the reasoning why he thinks so. Without further context, there's nothing there requiring you to agree.

Re: Electronic Structure of LK-99

#377

Post by marcosdumay »

sebzim4500 wrote: post #313
distortionfield wrote: post #118

Earlier quoted context omitted.

I’ve seen several tweets implying the gubberment is rushing out RTAPS to “cover up” the alien stuff

They rushed it out by... publishing a paper in a korean journal two decades ago?

And having it verified by a couple of Chinese labs.

Overall, that's not a common thing for the US government to do. It must be hiding something very important. /s

Re: Electronic Structure of LK-99

#378

Post by alexose »

scythe wrote: post #77
dralley wrote: post #30

My understanding is that the "99" in LK-99 is the year it they first synthesized the material, i.e. 1999. Assuming this is all true, why is it just now coming to light? Did they just not know what they had? (I have not been following this closely, maybe this has already been explained)

>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, requiri…

> but also why the samples seem to teeter on the edge of superconductivity so frustratingly.

Interesting! The uneven chunk shown in the original video was probably the best specimen they had after decades of attempts.

When I first saw it, my first thought was, "geez, why not at least try to make it uniform"...

Re: Electronic Structure of LK-99

#379

Post by jacquesm »

shawnz wrote: post #354
pjc50 wrote: post #273

Earlier quoted context omitted.

I think we're all horribly burned out by pop-science. How many battery "breakthroughs" have we seen on here? Meanwhile what actually works is incremental improvement in lithium battery manufacturing. The 1947 Golden Age SF is interesting because the "rocket fanatics" peaked in 1969 and humans haven't gone back to the moon, let alone conquered space. While the transistor succeeded to an extent nobody imagined due to t…

> I think we're all horribly burned out by pop-science. Speak for yourself, I'm happy to lend my positivity to people who think they might be close to breakthroughs even if they are unlikely moonshots, and you better believe I'll be maximally hyping up my own work if I ever feel like I am close to some kind of breakthrough too. That's part of the fun of being a living thing in this weird physical universe.

Exactly. I find myself a lot more engaged by people working on trying to get room temperature superconductivity checked off than by people figuring out how to do A/B testing on unsuspecting consumers to increase the number of ads that are clicked.

Re: Electronic Structure of LK-99

#380

Post by johncalvinyoung »

serf wrote: post #170
johncalvinyoung wrote: post #130

Earlier quoted context omitted.

As someone strongly in the first camp and not the second, this feels like a very odd observation. I despise generative LLMs and avoid using them at every opportunity. I'm also spending all my free time this week perusing arxiv preprints and Twitter threads. Make of my datum what you will. :)

> I despise generative LLMs and avoid using them at every opportunity. why? it's just a tool. despise how it was released, how it was trained, the people that operate it , whatever, but I can't really understand why someone would 'despise' a wrench -- even if it was used really poorly and produced by a shady company with a checkered past.

In rough order of priority (highest to lowest):

a) I do not believe that it produces useful-quality results for almost any of my use cases (Even if other concerns were addressed, I don't want to generate buggy code I then have to debug).

b) I believe many if not necessarily all generative AI models were trained unethically on copyrighted data

c) I am worried about the legal & copyright implications of using the tool to produce work products for my employer

d) I am concerned about the societal implications of the tool's existence, and how it's producing sub-human-scale work for (nearly) free, thereby eroding the market for a lot of human-produced output.

e) I dislike the amplified volume of low-quality content online over the last few months.

f) I'm not a fan of OpenAI as a business or a potential monopoly

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