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

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

#331

Post by jacknews »

retrac wrote: post #63
jacknews wrote: post #6

"this may spark a revolution in electronics as significant as the invention of the transistor, vacuum tube, and induction motor." How, exactly?

Superconductors are in the name. They're ideal conductors. As a corollary, superconductors coiled into a wire, shaped like an inductor, are also ideal inductors. By ideal, I informally mean nearly perfect in a mathematical sense. A thin superconductor can carry an almost arbitrary amount of electricity with 0% loss. This is a real-world application already for superconductors, but it requires cooling the entire condu…

My woo detector is blaring.

superconductors can't carry arbitrary current. A lot yes, but dependent on the material, temperature, magnetic field, etc. And on the subject of the material, can it even be made into a wire? Is it stable? How much does it cost? So assuming it costs about the same as copper, what are the benefits? 0% loss, vs, maybe 10%? So the grid is 10% more efficient? I mean, that's definitely useful, but...

Again for energy storage, what's the energy density? How much does it cost, if it's even possible to configure for that use? It sounds like you expect to power a car from an AA-sized cell - not happening IMHO.

Microelectronics; Can you make IC's with this? What is the feature size? We now have 10^11 transistors on a chip, can this do that? How costly? Even if it can, what's the actual benefit? Just power-saving, or can this ramp up to terrahertz speeds? Again, IMHO, not happening, except maybe for a few specialized switching applications.

Super-strong magnetic fields? Ultra-sensitive magnetic detectors - OK, these make sense.

I mean ambient superconductors would be a major thing, useful across many fields, and perhaps creating entirely new capabilities, but let's not get carried away that suddenly climate change is fixed, fusion will happen tomorrow (It'll never happen economically, IMHO), we'll all be moving around on levitating chairs like Wall-E, powered by AAs, etc, etc.

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

#332

Post by yreg »

psychoslave wrote: post #94
Mockapapella wrote: post #53

Earlier quoted context omitted.

Elon has personally owned x.com for a number of years now. Timeline as I remember it is Elon bought it in the late 90's, it changed hands when paypal merged with Elon's payment company, then he bought it back in 2017ish

Still make me laugh. I doubt the 2017 transfer costed $10. Let’s just recall all the more that domains are never really own, and that seems all the more crazy to my mind. Though I guess that when you let single individuals able to claim indefinitely large amount of ownership, that’s unavoidable waste of resources.

Buying x.com domain name is the last thing I would critisize on elon.

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

#333

Post by yreg »

djhope99 wrote: post #106

Interesting thread, looks like a lot of labs are on the charge to replicate this https://twitter.com/alexkaplan0/status/1684554551481835520?s...

I've been following this twitter user since this started and he is very much on the hype side.

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

#334

Post by retrac »

jacknews wrote: post #331
retrac wrote: post #63

Earlier quoted context omitted.

Superconductors are in the name. They're ideal conductors. As a corollary, superconductors coiled into a wire, shaped like an inductor, are also ideal inductors. By ideal, I informally mean nearly perfect in a mathematical sense. A thin superconductor can carry an almost arbitrary amount of electricity with 0% loss. This is a real-world application already for superconductors, but it requires cooling the entire condu…

My woo detector is blaring. superconductors can't carry arbitrary current. A lot yes, but dependent on the material, temperature, magnetic field, etc. And on the subject of the material, can it even be made into a wire? Is it stable? How much does it cost? So assuming it costs about the same as copper, what are the benefits? 0% loss, vs, maybe 10%? So the grid is 10% more efficient? I mean, that's definitely useful,…

I phrased it poorly - from an engineering standpoint, the amount of power a superconducting power line can carry is effectively limitless for practical purposes, in relation to the amount of material required. But yes, of course -- as I did say, eventually enough current flows that the magnetism induced breaks down the superconducting effect.

> what are the benefits? 0% loss, vs, maybe 10%?

With current lines, yes, rarely over 10% in practice. But what might be built without that barrier? There are many tens of gigawatts of undeveloped hydroelectric power in northern Canada, but that power has to be brought over some 5000 kilometres to New York or Chicago or Toronto. That can't currently be done. The losses are too high.

America's primary solar power generating regions in the future, likewise, appear to be far from the major cities.

> Again for energy storage, what's the energy density? How much does it cost, if it's even possible to configure for that use? It sounds like you expect to power a car from an AA-sized cell - not happening IMHO.

Yes, it's already used, real-world actual applications: https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...

The energy density is too low for anything like domestic use. It will probably be most useful at grid scale. The economics may not work out.

> Again, IMHO, not happening, except maybe for a few specialized switching applications.

Switching at just under 1 THz has been demonstrated recently. Anyway, I agree. I already said as much -- "a rather unlikely prospect".

C'mon. I'm just excited about superconductors. They're cool! Except hopefully not anymore! I don't believe anything I said was factually wrong. Your primary gripe seems to be that I'm not sufficiently pessimistic about the likelihood of some of the possibilities. So -- room temperature superconductors are probably not real. And everything I spoke of must be understood as conjecture and hypothetical, with large and unknown variables, regarding things like the practical cost and material workability of the room temperature superconductors, which may not even be possible. Better?

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

#335

Post by mrtranscendence »

Mizza wrote: post #284
alexose wrote: post #247

Earlier quoted context omitted.

The 'nays' getting lots of traction on twitter right now https://twitter.com/alexkaplan0/status/1684642852616192000

Some schmo with an instant coffee company. There's no need to surface random people's opinions.

I mean, he has a PhD in physics, at least. He's not just some rando off the street.

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

#336

Post by jeepers6 »

Zetice wrote: post #123
ChemSpider wrote: post #77

Earlier quoted context omitted.

Anonymous or not, the "MPI guy" explains why he came to this conclusion, and it sounds legit.

I feel like you anonymously and uncredibly (no offense intended) saying "sounds legit" kind of ignores the problem being pointed out here...

Yet my comment is the one flagged.

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

#337

Post by nomel »

geertj wrote: post #244
scarmig wrote: post #240

Earlier quoted context omitted.

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).

Interesting.. would you have a source for those rumors?

Comment below the image: https://twitter.com/8teapi/status/1684571913908293633

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

#338

Post by mustacheemperor »

madacol wrote: post #285
alexose wrote: post #247

Earlier quoted context omitted.

The 'nays' getting lots of traction on twitter right now https://twitter.com/alexkaplan0/status/1684642852616192000

For context, he is the same guy that went viral yesterday[0] excited with optimism, now saying there are other more possible explanations for the results besides superconductivity [0]: https://twitter.com/alexkaplan0/status/1684044616528453633

Just to keep us all up to date, he’s now linked a figure from the recently discovered third paper and returned to breathless excitement.

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

#339

Post by hatsunearu »

guerrilla wrote: post #154
hatsunearu wrote: post #132

Earlier quoted context omitted.

I was one of the people who said power is wasted in wires. When the charged stored inside a chip needs to change (like go from high to low), that energy associated with the charge needs to go somewhere. Currently most of the charge is dissipated in the wire and some of it within the transistor. If the wires have no resistance, the transistor will be the one dissipating the energy, not the energy simply disappears. So…

Ahh right. I didn't think of that. Thank you for explaining.

I wanted to add but my morning poop time was over so never had a chance to write this.

If you have two capacitors, say C1 and C2, and say their capacitance is both C.

Say C1 is charged up to 2V. The energy stored in that cap is 1/2 CV^2 = 2C.

Say C2 is not charged up.

The charge on C1 is Q = CV = 2C. The charge on C2 is 0.

Say suddenly you connect C1 to C2 via a lossless wire.

The charge on C1 and C2 must be equal before and after the connection since charge cannot be destroyed.

After the connection, the voltage on both caps will be equal, and the charge on them will therefore be equal.

Charge on each cap is 1C; voltage is therefore Q/C = V, V = 1V on both caps..

Now let's look at the energy on either cap. 1/2 CV^2 = 0.5C.

The combined energy on both caps are 1C. Where'd the energy go? We just said we connected the capacitors with a lossless wire, so it can't be dissipated there, and capacitors by definition cannot dissipate power.

The answer is that lossless wires cannot exist, and if you do the math more carefully, this time with real resistance and take the limit as R->0, you will see that the power-time integral of the wire (dissipated energy) will approach 1C.

The same argument can be made for integrated circuits; as your resistance drops, more and more of the portion of loss will be dissipated in the "other" sources of loss.

edit: superconductors are lossy at AC (but not as much as regular conductors get lossy at AC), and the capacitor connection is an AC phenomena so even with superconductors there will be a teeny loss even with superconducting wires. The rest of the loss will happen in other ways (EM radiation, dielectric loss, loss from capacitor resistance, etc)

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

#340

Post by hatsunearu »

smallnamespace wrote: post #265
jncfhnb wrote: post #237

Earlier quoted context omitted.

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.

One lab is definitely not adequate. Replication attempts don't give you an unambiguous signal, many things can go wrong. If one lab hasn't succeeded in replicating the paper, does that mean the paper is wrong, or just that a necessary step wasn't documented clearly or followed correctly? More labs trying to replicate give you more independent signals.

when an "adversarial" lab (as in, competing with the original lab) tries to replicate and succeeds, you can be pretty damn sure it's legit.
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