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Room temperature, ambient pressure superconductivity – this time for real?

scanalyst.fourmilab.ch

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Re: Room temperature, ambient pressure superconductivity – this time for real?

#231

Earlier quoted context omitted.

LOL they really renamed it X? I see they even bought x.com which surely they paid some ridiculous amount for, and yet they wasn’t able to spend any cent on original logo, at least X.org logo as an orange O.

Using a unicode character might have been deliberate. It lets anyone stick your logo on a post on another platform. Allows viral marketing even in places where posting an image is high friction and/or where hyperlinks are banned. We'll have to wait and see if such a move is a good one...

I just had a look to see if 𝕏.com was available, but it looks like the punycode encoding is x.com anyway.

Re: Room temperature, ambient pressure superconductivity – this time for real?

#232

Can someone ELI5 if the video with the magnet levitating is supposed prove something? Is this visual result only possible with superconductors? If so, why?

The levitation results from something called "diamagnetism" [1]. Diagmagnetism induces a magnetic field that opposes the original field; in this case it pushes the magnet away from the sample material.

All superconductors are strongly (perfectly, actually) diamagnetic, and its a classic cool demonstation of their properties. However, not all strongly diamagnetic things are superconductors. In fact, diagmagnetism is present in all materials, but it is usually swamped by other magnetic effects (ferromagnetism and paramagnetism).

[1] https://en.wikipedia.org/wiki/Diamagnetism

Re: Room temperature, ambient pressure superconductivity – this time for real?

#233

Earlier quoted context omitted.

What do you think the chances are of it being a measurement/instruments error? Edited to add: I am not a physicist. I don't know the subtleties of measuring experiments, and it was not my intention to state that there was a measurement error. I just wanted to ask someone for their assessment of the chances it was an error. It's a little depressing that people are so quick to assume the worst of others, but I get why.…

Small. Imperfect contact, unplugged terminals, etc. These are not 1st year grad students who don't know what they are doing. The authors have decades of research and fabrication experience, and publications to back it up. Comments that insinuate it could be those kind of novice mistakes (other comments on HN/reddit, not yours) are frankly insulting and speaks to a profound arrogance in being unable to accept a new di…

Compared to recent controversial results claiming the exact same thing (actually, more restrictive than this claim), it's not insulting it is what you should expect. The recent situation with Dias this year[1] is now under investigation as a case of data fabrication and he didn't even claim to have ambient pressure.

Frankly there are too many details missing to trust them. They've fabricated a thin film but not characterized it. It is well known that the properties of a material change when you go from bulk to thin film with a big dependence on the thickness. They don't mention how the resistance of this thin film is measured - that's important for what artifacts you might expect to see in your measurements (van der Pauw vs Hall bar measurements are the standard but they don't mention using either). Without characterizing the thin film it's also difficult to know, chemically and structurally, what you are measuring. I don't see any data confirming the quality of the thin film. The way the data is presented is such that it can be misleading, showing I-V curves instead of resistance when you are really trying to say the resistance is what is changing. The first paper doesn't even mention the insulator-metal transition that is present in the second paper which is bizarre - this is important if you are also claiming a superconductor transition close by and you would expect some discussion of this behaviour.

All of these are things that, one would hope, will be picked up by the reviewers as low hanging fruit before even really delving into the detail of the theory they present.

Decades of experience alone should not be trusted. Anyone can make a mistake, and not all the authors can be present for every experiment.

[1] - https://www.nature.com/articles/d41586-023-02401-2

Re: Room temperature, ambient pressure superconductivity – this time for real?

#234
post #215

Recent W&M Condensed Matter Physics Grad. Worked closely with HT Kim, not on this project. He is a trustworthy guy, knows his stuff. I think he is right when he calls the paper very sloppy, I am confused why there is no phase diagram and the sample purity seems suspect. These are things I think would have been addressed in peer review and would give me more confidence overall. Probably not fraud, but doesn't mean it'…

Glad to see a realistic take on HN. Endlessly frustrating to see people be like "this will be replicated in days". Yeah, sure, let every other lab just drop what they're doing, order all the reagents on express, do a thorough characterization making sure they understand the impurities and crystal phase, then perform good airtight measurements in a couple days. Crystal growth always has complications many times outsid…

To me the biggest mystery is why they didn't make multiple samples and send them to a few places that could verify their claims immediately. I understand that the papers were published before they really wanted to but they've also apparently have had samples for awhile it sounds like?

So assuming it's not BS (and I doubt that it is) it would lead me to believe that making the material is difficult to get right? The video they've produced uses a sample that isn't particularly elegant, to be sure.

I guess it's all conjecture at this point and healthy skepticism is warranted. A press conference would be nice.

Re: Room temperature, ambient pressure superconductivity – this time for real?

#235
post #157
post #7

Just for fun: Am I the only one who thinks there's connection between this and the UAP news that's coming out? RTSC would probably enable a lot of incredible energy & maneuverability capabilities... Sorry, indulging in a little off-topic conspiracy theorizing.

David Grusch is literally talking heresay with zero first hand accounts. Heresay is not allowed in courts for a reason. Snowden blew the lid off an international conspiracy, and he had gigabytes of receipts. Grusch has talked to people who work in information constrained spaces working on advanced materials with fancy codenames. If he was able to give literally any proof besides words coming out of his mouth and "tru…

Agree that it's second-hand...and even he states this. What about the 11 hours of testimony he's provided privately to congress that includes specific names, companies, and locations? What about the first-hand witnesses that congress has heard from that back-up Grusch's claims?

I mean, there are some seemingly crazy accusations...but even if only some of them are accurate, they're worth looking in to. And if it's all false, it's still very interesting that so many trusted individuals are making such crazy claims. That is its own huge issue.

Re: Room temperature, ambient pressure superconductivity – this time for real?

#236

Can someone ELI5 if the video with the magnet levitating is supposed prove something? Is this visual result only possible with superconductors? If so, why?

Magnets can also levitate over other magnets, so it's not only possible with superconductors. But it does happen with superconductors. The magnet will induce a current in the superconductor, which creates a magnetic field, which repels the magnet.

> Magnets can also levitate over other magnets

Earnshaw's theorem describes why a free-floating (paramagnetic) magnet cannot levitate over another such magnet. There must be at least one stable axis which is not from a magnet. See https://en.wikipedia.org/wiki/Earnshaw%27s_theorem

> The magnet will induce a current in the superconductor

That's a different sort of levitation. See https://en.wikipedia.org/wiki/Electrodynamic_suspension . We know it's not the same because you can see a magnet floating above a superconductor even though there's no motion.

The relevant reason is https://en.wikipedia.org/wiki/Superdiamagnetism .

] Superconducting magnetic levitation is due to superdiamagnetism, which repels a permanent magnet which approaches the superconductor, and flux pinning, which prevents the magnet floating away.

] Superdiamagnetism is a feature of superconductivity.

Re: Room temperature, ambient pressure superconductivity – this time for real?

#237
post #215

Recent W&M Condensed Matter Physics Grad. Worked closely with HT Kim, not on this project. He is a trustworthy guy, knows his stuff. I think he is right when he calls the paper very sloppy, I am confused why there is no phase diagram and the sample purity seems suspect. These are things I think would have been addressed in peer review and would give me more confidence overall. Probably not fraud, but doesn't mean it'…

Glad to see a realistic take on HN. Endlessly frustrating to see people be like "this will be replicated in days". Yeah, sure, let every other lab just drop what they're doing, order all the reagents on express, do a thorough characterization making sure they understand the impurities and crystal phase, then perform good airtight measurements in a couple days. Crystal growth always has complications many times outsid…

Feels like you’re strawmanning the idea here. It’s not “every lab” it’s “at least one lab”.

Jeez I sure hope at least one lab can spare the time to bother reproducing a room temperature semiconductor claim.

Re: Room temperature, ambient pressure superconductivity – this time for real?

#239

If this confirms, I really hope that the current limitation can be overcome. That would be brutal to actually find a ambient temperature and pressure SC only to have its usefulness for big real world applications be nerfed.

I think the most important thing is it proves it can be done. At one point it was thought impossible to run a 4 minute mile. There were all kinds of scientific sounding explanations why it just couldn’t be done. Then someone did it. Shortly after that, lots of people did it, because now people knew it was possible. If this is for real, it proves it can be done. Tons of money, work, and innovation will follow once peo…

I’ve heard this repeated. I vaguely recall it at least being a point of discussion in the novel Misery.

But… that seems like such a stupid idea. What evidence could they possibly have suggested?

Re: Room temperature, ambient pressure superconductivity – this time for real?

#240
post #215

Earlier quoted context omitted.

Glad to see a realistic take on HN. Endlessly frustrating to see people be like "this will be replicated in days". Yeah, sure, let every other lab just drop what they're doing, order all the reagents on express, do a thorough characterization making sure they understand the impurities and crystal phase, then perform good airtight measurements in a couple days. Crystal growth always has complications many times outsid…

To me the biggest mystery is why they didn't make multiple samples and send them to a few places that could verify their claims immediately. I understand that the papers were published before they really wanted to but they've also apparently have had samples for awhile it sounds like? So assuming it's not BS (and I doubt that it is) it would lead me to believe that making the material is difficult to get right? The v…

Skepticism is warranted, but apparently there's infighting in the group (only 3 people can be recipients of a Nobel Prize) and one jumped the gun to get his name out there. And also apparently fear of research espionage from the PRC (not as far-fetched as it sounds).
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