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LK-99 isn’t a superconductor

nature.com

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Re: LK-99 isn’t a superconductor

#431

Post by Eduard »

cogman10 wrote: post #410
drdeca wrote: post #400

Earlier quoted context omitted.

I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the point about "we use less efficient materials for power grid transmission than we could, because of costs". I suppose I didn't expect that we necessarily had like, the "absolute most efficient that could be made" (if that is something substantially more complicat…

The crux of the problem for superconductors used as power delivery is the "critical field" problem. [1] Super conductors are superconductive to a point. Once that point is crossed they turn into regular conductors. (I've seen ~1A cited. For context, EVs charge at around 500A). To make them useful for power transmission, you'd have to up the voltage to insane levels to avoid collapsing the field. [1] https://en.wikipe…

or just go the straightforward way and use several transmissions in parallel, as it is already done for existing superconducting lines in production.

The AmpaCity project in Essen, Germany, gives insights about the implementation details, as the involved parties were required to publish their work.

https://www.enargus.de/pub/bscw.cgi/?op=enargus.eps2&q=%2201...

for the specific aspect under discussion, the Karlsruhe Institute of Technology report is of interest:

https://www.tib.eu/de/suchen/id/TIBKAT:872231372/Ampacity-10...

Re: LK-99 isn’t a superconductor

#432

Post by tsimionescu »

dekhn wrote: post #342
tsimionescu wrote: post #314

Earlier quoted context omitted.

The point is that room temperature superconductors only matter if they have several other properties - they have to be ductile (easy to mold into wires), have good material resistance, maintain their superconductivity under high enough currents, and be cheap enough to produce. A ceramic room-temperature superconductor, like LK-99 would have been, is not a promising material at all, since it's extremely costly to make…

I was talking about a hypothetical RTSC that was amenable to industrial scale, not LK-99. Even so, merely knowing that RTSC with poor properties existed, would lead to massive search of the nearby (and other) spaces for better properties. See the history of glass optimization- hundreds of years of poking around with terrible quality glass, then a revolution during the Schott era, to modern day Gorilla Glass. Or silic…

Still, if LK-99 had turned out to be an RTSC, that wouldn't necessarily take us any closer to an industrial-grade RTSC. It could just as well be a false lead, an interesting material with some niche applications that would remain more of a curiosity than anything.

RTSCs are not like cold fusion - as far as we know, they should be possible, so finding one would not upend science in some huge way. If the ones we find don't also happen to have all the other interesting properties we need, then they may never have any significant impact at all. This is what seems to be missed.

If LK-99 had been an RTSC, it should still not have been major news outside materials science research, since it wouldn't have had any direct impact on the economy, nor any predictable pathway to one. Some other future discovery, if it ever happened, would have been the one that actually mattered. That potential future discovery may have built on the current work, but whether it would be 1 year down the line or 10 or 100 or never would not be knowable.

Re: LK-99 isn’t a superconductor

#433

Post by Joker_vD »

svetb wrote: post #412
drdeca wrote: post #400

Earlier quoted context omitted.

I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the point about "we use less efficient materials for power grid transmission than we could, because of costs". I suppose I didn't expect that we necessarily had like, the "absolute most efficient that could be made" (if that is something substantially more complicat…

Am not the author of that comment, but the fact that comes to mind is that aluminum is used for virtually all transmission and distribution lines - for price reasons - even though copper has better conductivity. If we did discover a room-temperature superconductor, I suspect it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compar…

In some desperate places, people would cut down aluminum power lines and sell them to scrapyards for some quick buck. But copper power lines? Those would be in a similar danger in many more places.

Re: LK-99 isn’t a superconductor

#434

Post by elihu »

svetb wrote: post #412
drdeca wrote: post #400

Earlier quoted context omitted.

I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the point about "we use less efficient materials for power grid transmission than we could, because of costs". I suppose I didn't expect that we necessarily had like, the "absolute most efficient that could be made" (if that is something substantially more complicat…

Am not the author of that comment, but the fact that comes to mind is that aluminum is used for virtually all transmission and distribution lines - for price reasons - even though copper has better conductivity. If we did discover a room-temperature superconductor, I suspect it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compar…

Aluminum vs copper is a good example. Another is that we already do use superconducting transmission lines in a few places. We could do more of that, but presumably it's expensive to install and/or maintain otherwise we'd be using it everywhere. I'm not sure what the longest or highest capacity superconducting links currently in existence are.

Re: LK-99 isn’t a superconductor

#435

Post by choeger »

What an amazing time we live in. It took weeks for the world to investigate this "discovery". Weeks. Not months, years, or decades.

We will see spectacular results from this kind of global scientific collaboration. I am confident that there will be an actual scientific breakthrough confirmed like this report got debunked.

Re: LK-99 isn’t a superconductor

#436

Post by doctorpangloss »

godelski wrote: post #171
thinkingkong wrote: post #2

It’s disappointing news but the excitement and amount of replication on this paper was pretty fun to witness and experience. To me the most interesting part was everyone talking about potential consequences, uses, the order of magnitude improvements we’d see in certain costs or areas. Pumps, MRIs, power grids, chips, etc. Great reminder what materials science can do to some underlying economics.

> but the excitement and amount of replication on this paper was pretty fun to witness and experience. I was really elated to see how people were so interested and getting to see what peer review in science actually looks like. How in the real world it is done outside of journals and conferences, which people frequently give the misnomer "peer review." I hope people will walk away from this experience with a better u…

> Because the truth is that our academic incentive structure has generally fallen out of alignment with the actual goals of science.

Did it though? Nobody published this, which is good, right? And then Max Planck Institute gave the most conclusive answer, and they're the most prestigious replicator-to-be mentioned, so that also sounds good right?. And now, Mr. L and Mr. K will not receive funding for this material, because it decisively failed to publish, which is also good?

I don't know. It sounds like the academic incentive structure worked really well here.

Re: LK-99 isn’t a superconductor

#437

Post by tsimionescu »

svetb wrote: post #412
drdeca wrote: post #400

Earlier quoted context omitted.

I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the point about "we use less efficient materials for power grid transmission than we could, because of costs". I suppose I didn't expect that we necessarily had like, the "absolute most efficient that could be made" (if that is something substantially more complicat…

Am not the author of that comment, but the fact that comes to mind is that aluminum is used for virtually all transmission and distribution lines - for price reasons - even though copper has better conductivity. If we did discover a room-temperature superconductor, I suspect it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compar…

> it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compared to what’s already available.

Note that there is no guarantee that that would ever happen. Electrical resistance is not the only thing you need for something to be an economically efficient power line. While superconductors are by definition excellent in terms of electrical resistance, there is nothing to guarantee that they wouldn't be too brittle, or too heavy, or too hard to mould into the required shape, or simply require materials that are too rare on Earth. And all of these would not be things that can just be worked around with better production processes or smart engineering - they would be fundamental limitations of the specific material, just like the low temperature requirements of currently known superconductors will never be improved with more research.

So this isn't a matter of when they would reach the point of being better economically, it's also very much a matter of if they would ever reach that point. Hopefully, we'll get lucky one day and find a material that is superconducting at room temperature and above, that is study and light and easy to make into wires and made out of abundantly available elements. LK-99 certainly wasn't most of these things. Even if it had been superconducting, it wasn't a good candidate for any of the other properties we want anyway, so it likely wouldn't have been much better than other known materials for most applications.

Re: LK-99 isn’t a superconductor

#438

Post by [deleted] »

choeger wrote: post #435

What an amazing time we live in. It took weeks for the world to investigate this "discovery". Weeks. Not months, years, or decades. We will see spectacular results from this kind of global scientific collaboration. I am confident that there will be an actual scientific breakthrough confirmed like this report got debunked.

[deleted]

Re: LK-99 isn’t a superconductor

#439

Post by dekhn »

tsimionescu wrote: post #432
dekhn wrote: post #342

Earlier quoted context omitted.

I was talking about a hypothetical RTSC that was amenable to industrial scale, not LK-99. Even so, merely knowing that RTSC with poor properties existed, would lead to massive search of the nearby (and other) spaces for better properties. See the history of glass optimization- hundreds of years of poking around with terrible quality glass, then a revolution during the Schott era, to modern day Gorilla Glass. Or silic…

Still, if LK-99 had turned out to be an RTSC, that wouldn't necessarily take us any closer to an industrial-grade RTSC. It could just as well be a false lead, an interesting material with some niche applications that would remain more of a curiosity than anything. RTSCs are not like cold fusion - as far as we know, they should be possible, so finding one would not upend science in some huge way. If the ones we find d…

It's like you're arguing with somebody different from me, who said something entirely different from what I said, while also agreeing with my unstated premise, and conditional language.

Re: LK-99 isn’t a superconductor

#440

Post by parker_mountain »

exmadscientist wrote: post #231
parker_mountain wrote: post #110

Earlier quoted context omitted.

> Technically an infectious disease expert but I don’t particularly care what they have to say about Covid over a random person on the street either. I would absolutely care more what they had to say over the rando, especially if they prefaced it with their level experience.

Yeah, uh, I wouldn't. There was a B- or C-list physics blogger a few years back whose graduate homework I used to grade. (I still remember this one, so that should tell you something.) He got very angry that I gave him zero credit for one particular question. But he: - did not use the standard/expected approach to this problem - did not explain what he was doing well enough for me to find him any partial credit (this…

I didn't say authority, and I didn't say trust blindly. I just said I'd trust someone with baseline qualifications over a random (presumably unqualified) person. lmao
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