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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

#271

Post by CitizenKane »

saberdancer wrote: post #215
tootie wrote: post #186

Earlier quoted context omitted.

I'm still unclear. Why is the test limit 110K? If this is supposed to be usable at ambient temperature then this seems like not a useful finding. Is it just some artifact of how superconductivity is measured?

Most materials are not superconductors at 110K. If this one is, it is possible Koreans did not fake room temperature results but rather their sample is slightly different for some reason, maybe pure luck, maybe some part of process that they didn't clearly define or that their precursor materials have certain impurities.

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 to the paper.

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

#272

Post by refulgentis »

callalex wrote: post #214
refulgentis wrote: post #200

Earlier quoted context omitted.

One prediction market company spent a day spamming e v e r y tweet with a link to their own stuff, so it's adopted a meme-y link to LK-99 but it's honestly unrelated other than a clever marketing campaign

My question is also broader than LK-99, and my point still stands.

And my reply still stands, if not read for signs of an adversary, you would read a comment that reinforces (B) of the (A) and (B) you offered people to reply with. Its for gambling addicts

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

#273

Post by proprietario »

ugh123 wrote: post #124

The linked video mentions something about "outer space islands" in the subtitles. Is that just bad auto-translation or did they seriously discover something amazing?

see this other comment[0] its most likely a translation issue

[0] https://news.ycombinator.com/item?id=36975492

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

#274

Post by snitty »

cogman10 wrote: post #256
d1str0 wrote: post #178

Earlier quoted context omitted.

Assuming they discovered a low cost, room temperature, room pressure, superconductor, there are many HUGE technological advancements that can be made that would impact your daily life. Possibilities include improved battery longevity in all devices(probably in an order of magnitude), low friction transport improvements (ie. cheaper high speed rail), and faster and higher bandwidth wired connections. https://en.wikipe…

> improved battery longevity No > probably in an order of magnitude Absolutely not. > Low friction transport improvements This material is superconductive at 110K (-163C). Not exactly usable for transport applications. > faster and higher bandwidth wired connections. Absolutely not, resistance has no impact on bandwidth. I've seen variations of this comment on hacker news. Superconductors are not magic dust to make t…

>and applications (like levitating a train) require too many amps for our poor wire to remain a special wire. (Most super conductive materials lose conductivity when amps are too high).

I was wondering if there was a current limit on superconductors.

1) Is there any understanding as to why superconductivity breaks down at higher amperage? 2) If so, is there any explanation as to why that doesn't require a PhD in physics?

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

#275

Post by HDThoreaun »

tshaddox wrote: post #229
asdfman123 wrote: post #223

Earlier quoted context omitted.

Those rules are defined in the actual bet. I think it was "three replications of room temperature superconductivity by X date" or something like that. I looked closely because I very much wanted to bet tens of thousands of dollars on "no", but I couldn't because I'm in the US. The two outcomes would be I'd make a lot of money or humanity would make the biggest breakthrough in generations.

> I think it was "three replications of room temperature superconductivity by X date" or something like that. That doesn’t sound like a sufficient market resolution condition. Surely it would need to be something like “declared by specific Party X to be a room-temperature superconductor” where Party X is sufficiently trusted by all market participants.

Manifold is a funny money market, polymarket is the only one with any semblance of volume in my experience. https://polymarket.com/event/is-the-room-temp-superconductor... resolution criteria also leaves a bit to be desired imo

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

#276

Post by e63f67dd-065b »

rfoo wrote: post #69
obituary_latte wrote: post #50

There are multiple mentions of "extraterrestrial super islands", is this a mistranslation of the Meissner effect? Great term nonetheless.

It's the mistranslation of room-temperature superconductivity. "super islands" is likely translated from 超岛 which sounds the same as 超导 (superconductivity). I have no idea how 室温 (room-temperature) became extraterrestrial, must be extraordinarily bad speech to text model. edit: could be 室温 (shi4wen1) -> shi4wai4 -> 室外(outdoors)/世外(out of this world) -> extraterrestrial

You're exactly right on the extraterrestrial part: the speech to text transcribed it as "最近我们这个有关世外超岛的话题非常的火热"

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

#278

Post by EthanHeilman »

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.

YBCO is used in cutting edge Tokmak fusion reactors like SPARC. I'm not sure how an 18% increase in allowable temperature would change how much closer you could move the magnets to the plasma. Squinting at Figure 1 in [0], it seems possible you could get significant increased in Q from 18% increase in temperature.

[0]: Overview of the SPARC tokamak. Journal of Plasma Physics https://www.cambridge.org/core/journals/journal-of-plasma-ph...

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

#279

Post by cogman10 »

snitty wrote: post #274
cogman10 wrote: post #256

Earlier quoted context omitted.

> improved battery longevity No > probably in an order of magnitude Absolutely not. > Low friction transport improvements This material is superconductive at 110K (-163C). Not exactly usable for transport applications. > faster and higher bandwidth wired connections. Absolutely not, resistance has no impact on bandwidth. I've seen variations of this comment on hacker news. Superconductors are not magic dust to make t…

>and applications (like levitating a train) require too many amps for our poor wire to remain a special wire. (Most super conductive materials lose conductivity when amps are too high). I was wondering if there was a current limit on superconductors. 1) Is there any understanding as to why superconductivity breaks down at higher amperage? 2) If so, is there any explanation as to why that doesn't require a PhD in phys…

> Is there any understanding as to why superconductivity breaks down at higher amperage?

This is a good read [1]

> As long as the induced magnetic field at the edges is less than the critical field, the material remains superconducting, but at higher currents, the field becomes too strong and the superconducting state is lost. This limit on current density has important practical implications in applications of superconducting materials – despite zero resistance they cannot carry unlimited quantities of electric power.

Tl;Dr (and probably wrong) as current flows through any conductor it creates a magnetic field. In superconductors when that magnetic field gets too strong it impedes current from being able to flow. A little like a traffic wave [2]. Everything works fine so long as there's enough space between cars to allow for them to speed up and slow down, but as the density of the cars increases if someone slows down that has a reverberating effect down the chain.

The magnetic field on a superconductor in turn induces a current on the conductor in the opposite direction.

Here's a video discussing some of the implications of this effect in a way that seems counter intuitive :) [3]

[1] https://en.wikipedia.org/wiki/Critical_field

[2] https://en.wikipedia.org/wiki/Traffic_wave

[3] https://www.youtube.com/watch?v=oI_X2cMHNe0

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