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LK-99: Team of Southeast University observed zero resistance below 110 K

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Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#291

Post by lannisterstark »

tigershark wrote: post #204
carabiner wrote: post #193

Earlier quoted context omitted.

No I mean why is this "huge" when each time that's happened it's been deflated within 12 hours: - initial LK-99 paper upload on Arxiv: HUGE, then it's probably nothing until replication (waiting) - DFT release: HUGE, then probably nothing (DFT has poor predictive power) - 110K SC: HUGE, then ... ? In every case it's been the laymen saying HUGE, then the experts saying it's probably insignificant. Then the laymen sett…

[flagged]

It is not that they are throwing s** at it, but rather that none of you have actually explained why this is actually "huge," as you have been saying multiple times but without actually providing any concrete examples. "It is huge, trust me bro," isn't it.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#292

Post by QuadrupleA »

saulrh wrote: post #248
QuadrupleA wrote: post #195

Can someone with field expertise explain the implications if this material were real / replicable / cheaply manufacturable? I see a lot of breathless excitement in these comments, as if free energy and perpetual motion machines are right around the corner, but from the few details I've delved into it's more like the electric grid might get 10% more efficient, MRIs might get a little cheaper, etc. What are the excitin…

The BIG change is if this supports high magnetic flux densities, in which case literally everything that depends on magnetism or magnets or electromagnets gets an order of magnitude better - ten times as much power per unit of heat disappeared and ten times as much power per unit of mass or volume or just ten times more powerful. Remember how battery energy density increased by a factor of five (nicads -> lithium-ion…

But wait - modern electric motors, for example, are something like 80-95% efficient (https://en.wikipedia.org/wiki/Electric_motor#Efficiency), which implies there's not a ton of room to grow. Do superconductors somehow enable 10x more torque output for the same watt of electricity? Or is it that you could have a small motor in the palm of your hand that can consume huge amounts of electricity and produce enough torque to crack a diamond?

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#293

Post by mike_d »

cpleppert wrote: post #237
modeless wrote: post #121

To me this is encouraging. 110K is really high! It's higher than YBCO which is what they make commercial "high temperature" superconducting tape out of. IMO if this is legit (I have no way of judging the source) then this is the first good third party evidence that the original researchers are not just doing some kind of fraud. A total fraud wouldn't have actually discovered a novel high-temperature, but not room tem…

They aren't reacting because this isn't really proof of anything. The test apparatus they used can't actually measure 0 resistance. Superconductivity is implied (thats the most straightforward explanation) but not actually demonstrated here. Its very hard to interpret from the limited data presented. There could be a whole host of contaminants, issue with the experimental setup etc etc. Its hard to go from look at th…

> The test apparatus they used can't actually measure 0 resistance.

Can you explain how you would make that measurement? It seems like your testing equipment would need to be made of superconductors as well, right?

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#294

Post by jeremiahbuckley »

alephnerd wrote: post #172
hyperman1 wrote: post #137

Earlier quoted context omitted.

It reminds me of Max Gergel's Isopropyl bromide book: When Hildebrand ran the baths the silver came out bright, and stuck to the objects; the minute he left troubles started. No one knew why. Shortly before he left to go into the antique business in Charleston he showed me the secret. It was his chewing tobacco, spat into the bath from time to time. From then on, one man in each shift chewed, and the problem was solv…

What's the name of this book? It sounds really cool! Any other recommendations on books about the history of MatSE/Chemistry?

Oh man, you are in for a treat! This was a terrific read even though I probably only understood 1/3rd of it.

Ignition! By John D. Clark

https://www.amazon.com/Ignition-audiobook/dp/B07CTW1M9D/ref=...

Or, maybe you’ve already read it, in which case: great job. Maybe someone else will see this comment and enjoy it.

I don’t want to spoil if for you, but I loved the last paragraph. I believe a new heroic age for the field is dawning.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#295

Post by kadoban »

selestify wrote: post #283
CitizenKane wrote: post #271

Earlier quoted context omitted.

It is apparently extremely difficult to fabricate LK-99 and most of the time the process being used creates similar substances but without appropriate Cu substitution in its lattice. All of the videos have been of generally quite small samples and the manufacturing difficulty is the purported reason. The SK also supposedly had more details on this but with the leak of the paper those haven't been cleaned up and added…

I thought the original hype around LK-99 was that it was supposed to be easy to manufacture with materials most labs have on hand? E.g. https://news.ycombinator.com/item?id=36865106

The ingredients and tools aren't exotic, but chemistry is still a pain in the ass.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#296

Post by ChadNauseam »

callalex wrote: post #184
modeless wrote: post #121

To me this is encouraging. 110K is really high! It's higher than YBCO which is what they make commercial "high temperature" superconducting tape out of. IMO if this is legit (I have no way of judging the source) then this is the first good third party evidence that the original researchers are not just doing some kind of fraud. A total fraud wouldn't have actually discovered a novel high-temperature, but not room tem…

What prediction markets are you looking at? Are there any concrete examples of these markets being accurate, or just a venue for gambling addicts to feel smart?

> Are there any concrete examples of these markets being accurate

There are prediction markets for US elections, which tend to be pretty good. In general you should only expect markets with high liquidity to be very hard to beat, and the US elections have relatively low liquidity, so IIRC Nate Silver still outperforms them (but only by a small amount).

The reason you should expect high-liquidity markets to be hard to beat is that, if they were easy to beat, you could easily get rich by betting on them. So the common-sense idea of "there's no easy way to get rich" implies that they cannot be easy to beat.

The main exception to this principle is when there's a huge amount of money that intentionally places "bad" bets on the market, usually because they want to hedge against something. (e.g. I don't want this to happen, so I'll bet that it will happen, that way at least if it does happen I'll make some money.) This is why the TIPS spread, which can be interpreted as a prediction market for US inflation, consistently over-predicts inflation. Entities that stand to lose from high inflation use TIPS to hedge, which causes the TIPS spread to be too high. This could be corrected with better market design, but the treasury hasn't done that yet.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#297

Post by scarmig »

mike_d wrote: post #293
cpleppert wrote: post #237

Earlier quoted context omitted.

They aren't reacting because this isn't really proof of anything. The test apparatus they used can't actually measure 0 resistance. Superconductivity is implied (thats the most straightforward explanation) but not actually demonstrated here. Its very hard to interpret from the limited data presented. There could be a whole host of contaminants, issue with the experimental setup etc etc. Its hard to go from look at th…

> The test apparatus they used can't actually measure 0 resistance. Can you explain how you would make that measurement? It seems like your testing equipment would need to be made of superconductors as well, right?

Usually superconductor resistance is measured using four probes: current goes through the two outer probes, and voltage is measured across the two inner probes. Then V=IR.

Lead resistance can play a role, but superconductivity is a phase transition: there's a significant discontinuity. It's not a matter of something going from 0 + e (for small e) to 0 (which doesn't happen), but one of going from x (x >>> 0) to 0. When that phase transition happens, it's obvious.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#298

Post by jychang »

selestify wrote: post #283
CitizenKane wrote: post #271

Earlier quoted context omitted.

It is apparently extremely difficult to fabricate LK-99 and most of the time the process being used creates similar substances but without appropriate Cu substitution in its lattice. All of the videos have been of generally quite small samples and the manufacturing difficulty is the purported reason. The SK also supposedly had more details on this but with the leak of the paper those haven't been cleaned up and added…

I thought the original hype around LK-99 was that it was supposed to be easy to manufacture with materials most labs have on hand? E.g. https://news.ycombinator.com/item?id=36865106

The materials are easily on hand. That doesn’t guarantee it was easy to manufacture.

It’s not made of out of exotic elements, mostly just lead and copper. So in theory anyone can make it, but it’s just hard to do it correctly.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#299

Post by Robotbeat »

snitty wrote: post #270
modeless wrote: post #121

To me this is encouraging. 110K is really high! It's higher than YBCO which is what they make commercial "high temperature" superconducting tape out of. IMO if this is legit (I have no way of judging the source) then this is the first good third party evidence that the original researchers are not just doing some kind of fraud. A total fraud wouldn't have actually discovered a novel high-temperature, but not room tem…

YBCO superconducts as high as about 93K, so we're talking 17K difference. Which is useful but not wildly so. LN2 boils at 77K, for reference.

Mercury based cuprate superconductors go even higher than YBCO, like 145K at ambient pressure.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#300

Post by ijustlovemath »

QuadrupleA wrote: post #289
ijustlovemath wrote: post #239

Earlier quoted context omitted.

Transmission loss is a real and important reason why you can't, say, cover the Sahara with solar panels to get unlimited free energy for mainland Europe and Africa (barring all the logistical challenges of actually pulling something like that off). This is because you lose a significant amount of energy just by moving it from one place to another. With RTP superconductors, you get near perfect transmission from the s…

From what I've read, grid transmission losses are something like 5-10% - e.g. this page ( https://www.eia.gov/tools/faqs/faq.php?id=105&t=3 ) cites 5% in the US. Fine and nice, but seems incremental, not earth shattering, and I wonder about the logistics / ROI of manufacturing thousands of miles of LK-99 cables to achieve that. But maybe I'm missing something.

The losses increase with distance, and decrease with higher voltages, which is why most cross country transmission happens at 740kVAC. But still, the energy you're using in your day to day life is almost always produced with 50-100miles of where it's consumed, because transporting it longer distances make losses uneconomical.
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