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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?

#391

Post by marcosdumay »

hinkley wrote: post #307
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.

What do you suppose the odds are that there's a Tin-based compound instead of lead based? (Which would effectively make a bizarre form of brass a superconductor)

I doubt this one chemistry will be all that useful on practice. But after people understand it, I expect them to recreate the effect with completely different components, not on just slightly different ones.

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

#392

Post by toast0 »

benlivengood wrote: post #58
downWidOutaFite wrote: post #49

Earlier quoted context omitted.

Even if we found the perfect material, where it was easy and cheap to create long strong wires for power transmission as well as semiconductor-scale nano wires, we'd be gaining something like (wild ass guess) 20% gain in efficiency. 20% would be nice but would it really beat the last hundred years of discoveries? I don't think so, especially with digital tech's profound world-reshaping continuing to accelerate.

Specifically you could lay undersea superconducting cables around the world and rely on a global electrical grid which allows for nearly 100% solar generation. Superconducting magnets become cheap and widely available which allows for maglev trains at massive scale. Costs for the LHC and similar experiments would drop dramatically. MRIs would only require air conditioning, if that; Modern cell phones are sufficient t…

> Specifically you could lay undersea superconducting cables around the world and rely on a global electrical grid which allows for nearly 100% solar generation.

Not really, when the sun is up over the Pacific ocean, there's not that much sun over land. Maybe a global grid happens anyway, but cabling losses aren't the only source of cost, so I'd put my money on more localized improvements.

Better interconnection between and within local grids (maybe a viable Tres Amigas interconnection, but even just better connections between sections of the major grids would help with grid management. Improvements in motors, MRIs, magnetic bearings, transformers, etc.

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

#393

Post by refulgentis »

amatecha wrote: post #384
JumpCrisscross wrote: post #379

Earlier quoted context omitted.

> fundamental best practice to always wash your hands thoroughly with soap if you handle leaded solder But people don't, particularly students, and sometimes they also let their irons run too hot at which point fumes become an issue. Also, there is an easy alternative, so why not. If the choice is lead superconductor or not, nobody is going to pause on a use case because there is lead. If they do, and if this is real…

Oh, sure. You could have just said that then. You instead originally said something about "no one licks the insides of the computers", which isn't the reason lead in electronics/PCBs/etc. is restricted, and what I was pointing out.

Usually people who are making the argument you were making with the words you were using are signalling that lead is "lump of rock from center of nuclear reactor" dangerous. Honest to god, a lot of people believe this

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

#394

Post by JumpCrisscross »

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…

> the material as it is might have limited applications

Is LK-99 part of a larger (either known or emerging) class of materials? I'm not understanding what the lead and copper ions are doing to create internal stress, and why that leads to superconductivity.

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

#395

Post by frognumber »

slashdev wrote: post #21

This is an unreviewed preprint coming out of South Korea. If it’s reproducible it would be the biggest scientific discovery of the last hundred years. It will literally reshape the world. However, the most likely thing is they made a mistake and the paper will be withdrawn. But imagine if it’s true.

No. It's not. The impact won't be bigger than, say, the jet engine (1935), nuclear power (1951), the computer processor (???), the internet (???), DNA (1953), or many others.

The past century has had a lot going on.

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

#396

Post by solarmist »

lilgreenland wrote: post #388
solarmist wrote: post #310

Earlier quoted context omitted.

In the video, it's when they stop moving the magnet, it maintains its position, neither repelling nor attracting. Several physicists have spoken up and said this, and a few other tells distinguishes it from any conventional materials, which is why they made the video to begin with I'm sure. That said I'm just parroting back the things I've picked up from this discussion.

When does the hanging copper maintain a position in the video? https://www.youtube.com/watch?v=EtVjGWpbE7k All I see is the normal dampening and dragging effects that I show in my physics classroom.

As I've said, I'm fuzzy on the details, so I'm relying on the expertise of the physicists here.

I can tell it doesn't react to a magnet in ways that I'm familiar with (copper, iron, other magnets), but that's all the detail I can tell from the video.

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

#397

Post by zardo »

inasio wrote: post #294
Tuna-Fish wrote: post #183

Earlier quoted context omitted.

Previous improvements in high-temperature superconductors already made it possible to build a MRI machine using LN2 instead of LHe. I think all existing operational units still use LHe, but using LN2 has been demonstrated in lab conditions, and the next generation of machines will almost certainly use it instead of helium.

Or maybe not anymore ...

It still might be worth cooling this with LN2, in many applications, assuming critical current and critical field scale up as temperature decreases as they do with other superconductors.

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

#398

Post by chasd00 »

traverseda wrote: post #82
telltruth wrote: post #71

Could someone explain why is this world changing?

Superconductors are basically perfectly conductive wire. Wires that transfer 100% of power over arbitrary distances and that don't heat up. Obviously there are limits, you can't put arbitrary power over a hair thin filament but as long as you're under that limit you get perfect efficiency. MRI machines can be made a lot simpler as you no longer need to use liquid nitrogen to cool the superconductors. MRI machines cou…

i bet companies that make elaborate cooling system for gaming pcs are getting nervous hah.

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

#399

Post by jacquesm »

colechristensen wrote: post #324
jychang wrote: post #283

Earlier quoted context omitted.

250mA at 25 Celsius, according to the paper

Oof, all right then. Perhaps there's room for improvement, but there would need to be a lot before this is useful/competitive even in lab settings. For comparison, high temperature superconductors (in this context high temperature means tens of degrees kelvin) like the recently rather revolutionary ReBCO has critical current values measured in hundreds of thousands of amps per square centimeter. That would be a facto…

It's a thin film according to the article linked, but there is no mention of how thin it is (it could be a monolayer) and there is no mention of how wide the film was so the 250 mA figure can not be used to determine whether or not there is 'room for improvement' or even a necessity for that (unless it was already normalized, for which I see no evidence). The 'Critical current' isn't mentioned at all in terms of the cross section of the conductor, just as a function of temperature and magnetic flux which they really should have provided to be able to make sense of the figure. ReBCO is 8 MA / cm^2 (that's million, not milli), the thin film layer they tested with could well be so thin that it is in the same ballpark or it could be a small fraction.

This is clearly a very early result and until they have more insight into how it works (assuming it really works...) we'll have to be patient before we get more meaningful figures on the actual current carrying capacity of thicker conductors made out of this stuff. They were happy enough to be able to prove superconductivity at room temperature and normal pressure, clearly they are still a ways away from being able to line up a comparison with ReBCO with respect to current density. But surely that will happen soon if this is real.

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

#400

Post by tga_d »

fijiaarone wrote: post #385
xxpor wrote: post #322

Earlier quoted context omitted.

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

If you think lead is scary, wait till you hear about carbon dioxide.

I mean, modulo edge cases, lead is a lot scarier than CO2; it's only because of the ridiculously obscene quantities of CO2 being produced that it's a more immanent threat. There's obviously not enough information yet to weigh the value/consequences of the amount of lead used here, but if your measure of whether something is a good idea for mitigating carbon emissions is just "it's not carbon emissions", you're going to find yourself kicking a can a bit down the road, or (much) worse.
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