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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?

#501

Post by dotnet00 »

remote_phone wrote: post #468
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…

I genuinely hate responses like this. For some reason, there’s a contingent of people that think that by poking holes and pooh-poohing things, it gives them clout. It happens far too often in tech and I hate it. Look how often the post has “can’t” or “couldn’t”. Instead of giving reasons why something sucks, how about being supportive and talking about why it’s awesome and what possibilities this opens up?

While I often agree that the tone on these kinds of posts on HN is often annoyingly and unproductively cynical, I think him just pointing out the current limitations of the result is not that much of a problem. It isn't like he's making the overused "perpetually 20 years away" joke about potentially revolutionary technologies.

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

#502

Post by jiggawatts »

floxy wrote: post #412
XorNot wrote: post #246

Earlier quoted context omitted.

That video isn't very convincing. The usual test is that the material can float above the magnet.

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.

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

#503

Post by hatsunearu »

valine wrote: post #462
hatsunearu wrote: post #455

I don't have any proof of this other than "vibes", but I read through the Korean website for their research lab and I'm getting major scam vibes: https://qcentre.co.kr/ Hard to put it into words, but there's something that just doesn't feel right--I'd be very skeptical of these results.

It would be a really dumb scam. The paper is allegedly easy to reproduce. It’ll be proven or disproven in short order, where’s the motive?

No idea, but there's a lot of high profile scams where it seemed really fucking dumb just like this one.

Like the Schon scandal comes to mind. Super easily non-reproducible but somehow the dude was adamant that it was legit and everyone ate it up.

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

#504

Post by kibwen »

petsfed wrote: post #350
xxpor wrote: post #322

Earlier quoted context omitted.

One catch would be the use of lead would restrict the use cases fairly heavily

Its not a dirty secret, but just like the rules on chemicals under the organic certification, if you can show that there's no way to do what you want to do with lead-free, you can get an exemption. I suspect that "significantly lowers the cost of power generation" would outweigh "contains lead".

> if you can show that there's no way to do what you want to do with lead-free

The bar is even lower than that. For example, bullets are still made of lead, not because it's necessary, but because it's cheap, and despite the fact that it contaminates the meat of the hunted animal with lead.

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

#505

Post by sheepscreek »

xxpor wrote: post #322
sheepscreek wrote: post #48

One of the authors in a related paper[1] is Hyun-Tak Kim. He has many publications in peer-reviewed journals[2]. One even has > 1500 citations[3]. I can't tell if there is a catch anywhere, this seems pretty legitimate. Also, unlike some previous claims that required sophisticated setup to reproduce, this seems dead simple. I think we will hear from other researchers very soon. 1. Superconductor Pb10-xCux(PO4)6O show…

One catch would be the use of lead would restrict the use cases fairly heavily

This is a phenomenal find in any case.

As for how to avoid lead poisoning, coat the lead with a thin layer of some substance, perhaps a plastic or rubber that doesn’t affect its magnetic capabilities.

Or perhaps they can galvanize it with safer metal, leaving a really small part exposed.

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

#506

Post by nick__m »

mcv wrote: post #459
baq wrote: post #451

Earlier quoted context omitted.

Can you make wires in chips out of this? MRIs are nice but maybe zero resistance between transistors on my phone’s cpu is cool, too?

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.

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

#507

Post by knicholes »

marcosdumay wrote: post #245
alexb_ wrote: post #231

Earlier quoted context omitted.

Just give it to me straight - when will the levitation give us hoverboards?

As long as you only want them to hover over a magnet...

I want them to have enough current passing through them in a rod shape that it will run the current against the Earth's magnetic field to cause vertical movement.

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

#508

Post by hollerith »

kibwen wrote: post #504
petsfed wrote: post #350

Earlier quoted context omitted.

Its not a dirty secret, but just like the rules on chemicals under the organic certification, if you can show that there's no way to do what you want to do with lead-free, you can get an exemption. I suspect that "significantly lowers the cost of power generation" would outweigh "contains lead".

> if you can show that there's no way to do what you want to do with lead-free The bar is even lower than that. For example, bullets are still made of lead, not because it's necessary, but because it's cheap, and despite the fact that it contaminates the meat of the hunted animal with lead.

Tangentially, the US Army has completely stopped using lead in bullets. Their 5.56 NATO ammo has copper where the lead used to be (i.e., inside a brass jacket) which reduces performance because copper is only 2/3 as dense as lead.

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

#509

Post by jacquesm »

freeone3000 wrote: post #499
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…

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 well be something much more interesting (Josephson tunneling is briefly mentioned in the article). That could theoretically give rise to very efficient switching gear and if it can be miniaturized enough to efficient CPUs and memory. This is because the typical transistor uses power mostly in the time between the transition between the 'on' state and the 'off' state, when it is acting as a resistor. If you could get rid of that resistance during the transition then you might be able to reduce the amount of power a given circuit uses, but there are still lower limits off losses that you won't be able to escape, so it will not make your CPU magically use zero energy.

Given the contents of the paper such applications are a very long way off and may in fact never happen. Let's first see (1) if it is true and (2) if it is true how well it stacks up against copper wire of the same diameter and commercially available super conductors in terms of cost and practical current carrying capability. If that's all good then this will really be a game changer.

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

#510

Post by floxy »

valine wrote: post #462
hatsunearu wrote: post #455

I don't have any proof of this other than "vibes", but I read through the Korean website for their research lab and I'm getting major scam vibes: https://qcentre.co.kr/ Hard to put it into words, but there's something that just doesn't feel right--I'd be very skeptical of these results.

It would be a really dumb scam. The paper is allegedly easy to reproduce. It’ll be proven or disproven in short order, where’s the motive?

Imagine that someone is about to run out of funding. They spin up an semi-plausible story that they have just discovered something great. But "the man"/big oil/pharma/Illuminati is suppressing you and the truth. It might allow them to save face with certain people in their social circle (at the same time burning their bridges in the larger world). And/or your creditors might think you have gone crazy and not try to collect on their debts. And/or they might be in the midst of a manic phase of their bipolar disorder.
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