Possible Meissner effect near room temperature: copper-substituted lead apatite

Ask your hometown to build an antigravity skating rink with magnet shoes.

I envision a future where maglev trains whisk you to ice fishing.

You'd have to clean out all the ice cream though.

Happy to help with clearing out the Ice Cream...

Levitating ice cream

There's plenty of researchers working on material simulation on a molecular level. It's not easy to just search millions of possible combinations and accurately predict their behavior

Isn't the whole point that it's something we might not predict from what we understand about the materials so far? Why would it be likely that a simulation would do better than theory at predicting unknown experimental results?

You might hit on some interesting interactions between known properties that haven't been investigated but I would assume the real interesting results are from things we just don't know to model, or how to model.

This is done across many disciplines to try and aide in new discovery paths. Typically you’re limited in exactly what you can simulate and often times solution candidates may be found that are impractical, currently impossible, or perhaps actually impossible to produce. Sometimes you can add search constraints to tie simulations together to narrow down such false positive solutions found but not always. Heck in some cases it’s literally cheaper and more accurate to do the bench science no matter how alluring virtualized renditions may be.

Most fields are still left with piles and piles of potential solutions to sort through. They often select candidates that are the cheapest and most practical to approach or they have high suspicion of success and pursue those. At the end of the day though we don’t have full universe simulators at every scale we’d want, we have very specific area simulators within very specific bounds. You have to go out an empirically test these things.

But this is and has already been going on for decades across most disciplines I’ve interacted with, they just weren’t using DNN or LLMs at the time but domains are adopting these as well to leverage where feasible in the search process.

I work with a variety of people interested in leveraging simulation and everyone wants to take the successes they see in LLMs or say RL from AlphaStar or AlphaGo and apply them in their domain. It’s alluring, I get it, the issue is that we often lack enough real understanding in domains and the science isn’t as airtight and people think it is, its too general or narrow, or on some cases we have good suspicion of how to build better more accurate simulations but there’s not enough compute power or energy in the world to make them currently practical, so we need to take some tradeoffs and live with less accurate and detailed simulation which leads to inaccurate representations of reality and ultimately inaccurate solution suggestion candidates.

You far overestimate the state of the art, and even our basic understanding of what superconducting is mechanistically. Simulating a single atom, alone in the universe is still a struggle not quite achieved.

Quantum computers are still not useful, fwiw.

Supercomputers (the classical kind) typically don't want to run codes that try lots of combinations; they were designed for, excel at, and cost a lot because of, the need to speed up single runs at a time. This is partly due to history, and partly due to definitions of supercomputers, but every time I proposed runs like this (proteins/drugs) to the supercomputer centers, they told me to bug off because my codes "only scaled to 64 processors" (that's 64 servers, mind you; before SMP was common).

We did what you described using idle cycles at Google (search for "Exacycle") and we got great results doing large scale parameter explorations (either randomly sampled, or sampled based on where the previous sims suggested looking next)- although, nobody actually did material simulations like this, we did proteins.

Realistically, almost nobody does this because it's just not cost effective (the search space is too large, the loss functions aren't accurate enough, and it uses TONS of energy), and more importantly, somebody else is just going to find a way to generate 75% of the results with 25% of the energy, and that person will get published faster.

To be clear, you mean a freezer meant to contain food. Laboratory freezers can easily go lower without being remotely exotic (in design or construction).

So a normal freezer is already sufficient? 250K is about -23 degrees celsius.

That's without laser cooling, near-field thermophotopoltaics (TPV)), or thermoelectric solid-state refrigeration.

Infrared photons are thermal energy. Thermophotovoltaics and thermoelectrics convert work due to the thermal gradient into electricity.

Laser cooling: https://en.wikipedia.org/wiki/Laser_cooling

Cooling with LEDs in reverse: https://issuu.com/designinglighting/docs/dec_2022/s/17923182 :

"Near-field photonic cooling through control of the chemical potential of photons" (2019) https://www.nature.com/articles/s41586-019-0918-8 https://scholar.google.com/scholar?cites=8589611114160282602... :

> This demonstration of active nanophotonic cooling—without the use of coherent laser radiation—lays the experimental foundation for systematic exploration of nanoscale photonics and optoelectronics for solid-state refrigeration and on-chip device cooling.

My basic kitchen freezer can do -25. And that is a very basic and cheap freezer, so I think it would be relative easy to push it a few more degrees down.

That is 1,5 to 1,6 million times atmospheric pressure...Slightly impractical?

Was a joke, I didn’t actually voted him down

> Which, mind you, all turned out to be faulty interpretation of their data.

Which we should be critical of, but understandable, since that's one of the main reasons to publish (and why I think it is weird we say arxiv papers aren't peer reviewed. That was probably one of the most peer reviewed works in the last decade) and since we're all human. Science is full of mistakes, and is unsurprising when a lot of it is literally trying to do things that humans have never done before (much more to science than this too).

What I thought was really cool about LK-99 is that it isn't too often that people get a first hand look at what goes on inside the science communities. An abnormal amount of attention and openness, but illustrative. Just not sure this is the takeaway people got. But I saw science working in action, and it was really cool.

Extraordinary claim should be backed by extraordinary tests. So why do they publish if they're not 100% confident ? Why not wait to be certain ?

For this particular example, sure. I mean for this particular subject you'd have to hand in a really bad paper to get rejected, like past unintelligible, because the breakthrough is big. But I thought we were talking in general. There's also very clear downsides to this particular example by not being exceptionally cautious, because even a hint of hype can make them look like incompetent fools if they aren't correct. Though that wouldn't be good either because they clearly aren't. It's easy to make mistakes in science and even as I frequently told my friends last time, there was something different here and it'll probably end in failure (which it did) but that we'll learn something important (which looks likely to be true given this paper).

That’s possible but far less likely than the alternative explanation that either this is bunk too or LK-99 contained signal that people dismissed due to a hole in our methodology.

The thing is.... all the failed reproductions of LK-99 were based on the leaked version of the paper, which according to the authors is missing some information/steps for production. They said they would publish the complete/final version of the paper in 2024, waiting to see that.

Huh, today I learned. In chem in college I was just taught 20C.

Now you're nistpicking.

IUPAC is *S*TP, NIST is *N*TP

standard and normal

Does "cute" mean something different in Chinese?

Examples from that page put through Google Translate:

"Submitted by: Guided by the big assembly, with really cute stupid, wash the teacher,Sekiyama Pass, Fire Machine Immortal, Frog, Teacher Chen, etc"

"The rivers and lakes are far away, and I still remember that the cute and stupid sent the statement of "don't do it, whoever likes to do it" several times, and began to return to the old business in a few days. Don't say it, I really believed it at the time. Only the scumbag told me, impossible, absolutely impossible, he burned dozens of furnaces, much more fierce than us."

Not a physicist but my understanding is superconductors have max amount of current you can put through it, so its not clear it can be used for free energy distribution at scale even if it is a super conductor.

Not sure how much more humanity/civilization/the planet can take if we're still accelerating.

this material is very similar to lk99, nobody would be studying it if not for the lk99 hubbub

Among other things, critical current in bulk ceramic superconductors depends on cross-sectional area, so while it seems reasonable to make a ribbon-like structure, the 3rd dimension does matter. You can't make it effectively 2D.

This - these aren't hopeful people with a layman's understanding cheering on the scientific method, they're hype bros looking to gather gullible followers and shill cryptocurrencies to them based on yet another thing they're utterly clueless about and don't care to inform themselves on.

Those "twitter gurus" were actively trying to recreate the paper, and a lot of those "twitter gurus" are actual founders doing actual hardtech startups with relevant degrees and labs.

You know you can block and mute people on Twitter, right? The actual true grifters of the kind you are talking about are pretty rare in terms of a per user basis (though get get lots of distribution), and most of them are very bad at concealing themselves.

People will bet on literally anything. That's their own problem, not mine.

More like people with relatively low familiarity with a field posting with the confidence of ChatGPT and, like LLM spam, recycling and reposting so much material that adds nothing to the conversation that any actually useful content is buried.

Possible, but many of the economic benefits would be lost if you needed to do it covertly.

Can't exactly have room temperature superconducting monorails all over the nation without someone questioning exactly how you have room temp superconductors and nobody else does...

Any technology will have a very long way from the initial discovery to widespread application. A swarm of tinkering US startups will beat any Chinese megaproject. You propose that it is developed covertly to such an extend that it becomes a game changer that disrupts the current power balance before the US realises. I strongly disbelieve that such things can happen outside of fiction. For example, Manhattan project was known to the Soviets very early.

And do they actually solve more science or engineering problems than US?

The annual NIH budget is >$50B and they earmark large portions of that for specific problems. This has paid off well for the US which became the world's leader in biotechnology and has maintained it for some time. NSF is another $11B, DOE another $50B (part of which is military, I admit).

Those only have a limited dependence on dozens of senators; the NIH typically gets most of what it asks for every year. The US has funded science at spectacular levels in a bipartisan way for some time (that may change in the future). Of course there is still a lot of political bargaining, I'm not going to deny that.

What's interesting is that we could clearly spend even more if we felt it was a priority. There's so much that could be taken from military spending without having a direct impact on our defense. But I don't think we want to do that; during my grad school career, the NIH budget almost doubled, which led to a huge bolus of grad students minted as PhDs, who then had no jobs beccause the size of faculty positions didn't change nearly as quickly.

I admire China's efforts and I see a lot of similarities in China to the US around 1900: the time when the balance of industry and technology shifted from EU to US, but growing your industry super-fast runs the risk of overheating and meltdown.

LIGO?

> "Resting on your laurels" always ends badly.

And history is littered with examples of technological disruption ending empires

In this movie

https://en.wikipedia.org/wiki/Brainstorm_(1983_film)

a researcher builds a device that can record and play back experiences which takes up most of a room, in a meeting with his boss, he receives some secret microchips made of a room temperature superconductor that he uses to make headsets.

Back when I worked at TI we had a neat machine that used X-Rays to map and reverse competitor chips (mostly to discover they were duping ours). It would work down to just short of a 10nm resolution.

You'd need to use gamma spectrography to map out more modern chips. I'm sure someone's got the equipment somewhere; the chip manufacturers themselves must verify they got a good etch somehow.

How did they mishandle Rabin?