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The first room-temperature ambient-pressure superconductor?

arxiv.org

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Re: The first room-temperature ambient-pressure superconductor?

#511

Post by cguess »

m463 wrote: post #320
marcosdumay wrote: post #293

Earlier quoted context omitted.

Ok, let me just add the obvious disclaimer: don't try this yourself unless you have a pretty good understanding of chemical lab safety. Really. It's more likely that you will contaminate your land, and possibly your neighbors land too than that you will manage to replicate it.

Yes, but chernobyl produced a lot of useful electricity (at first)

For years, and then after the explosion too. The last reactors were decommissioned around 2015 (it takes years, so the dates are bit washy).

Chernobyl wasn't the accident people seem to think. It wasn't inevitable, it was the result of numerous self-serving decisions exacerbated and even required in the very messed up Soviet system of management that enforced following the party instructions over all other possible complications.

Re: The first room-temperature ambient-pressure superconductor?

#512

Post by XorNot »

jiggawatts wrote: post #502
floxy wrote: post #412

Earlier quoted context omitted.

This is the better video: https://sciencecast.org/casts/suc384jly50n

That looks like a chunk of pyrolytic carbon, which can also float above a magnet.

AFAIK doesn't pyrolytic carbon need a N-S field in order to levitate? That's the one key difference I can see - this looks like the traditional superconductor trick of just levitating in a simple field.

i.e. not like some of the ones you'd see here: https://www.youtube.com/watch?v=Vy9uWXgbKy0

Re: The first room-temperature ambient-pressure superconductor?

#513

Post by JumpCrisscross »

jacquesm wrote: post #487
serf wrote: post #483

Earlier quoted context omitted.

>There are a lot of examples where something seems perpetually 20 years away. I'd advise tempering the transistor-based optimism with just a skosh of fusion energy skepticism. most of the common examples are in-the-works or exist in some form, they just don't satisfy the 'every-person' checkbox yet. AI? sure. Flying cars? sure. Robots? sure. Fusion is in the works, too. Tens of billions of dollars being thrown into t…

> Fusion energy production doesn't (really) have that equivalent. It does, actually. It's the miniaturization that's the hard part.

> it's the miniaturization that's the hard part

We don't have a working fusion system to miniaturize. Stellar fusion happens at much lower temperatures than what we're trying to do on Earth.

Re: The first room-temperature ambient-pressure superconductor?

#514

Post by danbruc »

carabiner wrote: post #317
danbruc wrote: post #31

After skimming the paper, it reads like a legitimate paper even though I have zero expertise in the area. That it is in Word instead of LaTeX makes it feel a bit less legitimate to me and they could of course always have some error in there setup. The most notable thing to me was that this was done in a thin film where structural defects are supposedly responsible for strain in the material which in turn enables the…

> After skimming the paper, it reads like a legitimate paper even though I have zero expertise in the area. Ummm am I the only one who finds this line hilarious?

If you read some real papers and some crackpot papers, you can learn to identify bad papers without having to have much knowledge on the topic. Bad papers will, for example, often lay out trivial things at length, i.e. have very low information density. Or they will say things that are incoherent even if you do not understand all the details. Or there will be no references to legitimate other literature. This paper is dense and coherent and does not contain obvious nonsense even to an non-expert. More I did not want to imply, just that it does not look like a a crackpot paper. For a more detailed judgment, for example whether the experiments they performed or the numbers they got are reasonable or something like that, I am indeed unqualified.

Re: The first room-temperature ambient-pressure superconductor?

#515

Post by floxy »

jacquesm wrote: post #496
floxy wrote: post #492

Earlier quoted context omitted.

Right. Everyone should just read up on Earnshaw's theorem to know what all the boundary conditions are. https://en.wikipedia.org/wiki/Levitron

I wonder how long you could get one of those to spin in a vacuum. Halbach arrays with compensating coils have been proposed for some interesting applications, such as low loss flywheels for electrical storage. I don't know if that ever got commercialized but I do recall that some prototypes were made by a US company. I can't find a reference to it though.

>I wonder how long you could get one of those to spin in a vacuum.

Not too much longer apparently...

https://www.youtube.com/watch?v=mn7IedCgva0

Re: The first room-temperature ambient-pressure superconductor?

#517

Post by arjvik »

nick__m wrote: post #506
mcv wrote: post #459

Earlier quoted context omitted.

CPUs that don't generate heat? That would be pretty awesome.

Superconductivity is not enough for a cpu that doesn't generate heat, you would need a cpu built of reversible logic gate. Thermodynamics requires that when you destroy a bit of information you generate at least 2.9×10−21 J. It's the Landauer's principle.

Say we use this (or any other) superconductor to build an AND gate. Assume one input is zero, so the information of the other input is lost.

I assume the energy lost as heat occurs due to the "current" going into the and gate having "nowhere else to go" other than to dissapate as heat?

If that's the case, simply redesigning our logic gates to have as many outputs as they have inputs, with some of these outputs feeding indirectly back to the power source without being read, seems feasible.

Re: The first room-temperature ambient-pressure superconductor?

#518

Post by jacquesm »

gerdesj wrote: post #498
andreiklochko wrote: post #389

Guys, even if everything in this paper is true, the material as it is might have limited applications. From what they show, the critical field and critical current seem very low. 2500 Oe is like 0.25 Tesla. Even REBCO at 77K is >1T. And 2500 Oe is not even at critical temperature but much lower. From skimming through the article I couldn't find the sample size of the current measurement to get the critical current de…

When I were a lad ... I remember the first superconductors (long predicted) being announced in the mid '80s. They stayed high on the nerdy headlines for quite a few years. Excitable write ups in New Scientist for us civilians. Nuclear fusion was still 50 years off but room temp superconductors were only a few years off (nope). I went to a posh school in Oxfordshire in the mid to late '80s and my physics class (form)…

Very true. I remember cheering since the mid 80's every time the temperature for superconductivity went up, sometimes with 20 degrees K in one go. And then it was quiet for a long long time with a plateau. More recently, two major jumps, the last one of > 50 degrees (2017, H2S), and now this...

https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002...

Re: The first room-temperature ambient-pressure superconductor?

#519

Post by paulddraper »

jacquesm wrote: post #456
andreiklochko wrote: post #389

Guys, even if everything in this paper is true, the material as it is might have limited applications. From what they show, the critical field and critical current seem very low. 2500 Oe is like 0.25 Tesla. Even REBCO at 77K is >1T. And 2500 Oe is not even at critical temperature but much lower. From skimming through the article I couldn't find the sample size of the current measurement to get the critical current de…

This is a dancing pig. The thing to appreciate is not how well it dances but that it dances at all .

Hahaha perfect analogy

Re: The first room-temperature ambient-pressure superconductor?

#520

Post by TaylorAlexander »

jacquesm wrote: post #509
freeone3000 wrote: post #499

Earlier quoted context omitted.

Could we, for example, make circuit traces out of it?

You could probably do that but it wouldn't be a whole lot better than the existing traces: it's not usually the resistance that limits the size of circuit traces but the mechanical requirements, such as your ability to connect to them and to space them apart so you don't get crosstalk due to capacitive or inductive coupling. If you could use it to make circuits, especially of a high level of integration then it might…

Sometimes the resistance of the trace matters. I’m designing a motor controller that needs to carry 100 amps and the resistance of the copper means that large planes are needed to carry the current without overheating. Beyond that I agree with everything you’re saying.
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