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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

#311

Post by loxias »

scarmig wrote: post #305
loxias wrote: post #290

Earlier quoted context omitted.

[flagged]

Spicy take: Theory is shit (betraying my bias here). If someone released a paper that theoretically proved a material was a superconductor from first principles, I would ignore it, every bit as much as I would if it had the opposite results. In materials, experiment has always led theory. Theory has use in suggesting new angles to explore with experiment, but theory is fundamentally reactive: get new data, try to fit…

I have little to add other than I f---ing love your spicy take :D

...and agree with most of it. Yeah ofc I know results lead theory in all physics esp materials... :)

Disagree re: the not getting how science works, though you might be facetious?... the fact that it just so happens that if you plug the numbers obtained by experimentation into a current reasonable model, HUH, SOMETHING INTERESTING! That's huge. No, I don't think that's a non-result, and (intentionally using the "appeal to authority" logical fallacy in place of a real argument) Dr. Derek Lowe agrees, so we know how science works. ;-)

Can you expand more about what you mean by "the politics here"? (your sentence 1-5 I couldn't agree more with)

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

#313

Post by oska »

loxias wrote: post #290
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…

[flagged]

> a Chinese or Russian lab claiming something and posting to twitter has very little value

Why the national specificity here ?

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

#314

Post by scarmig »

loxias wrote: post #311
scarmig wrote: post #305

Earlier quoted context omitted.

Spicy take: Theory is shit (betraying my bias here). If someone released a paper that theoretically proved a material was a superconductor from first principles, I would ignore it, every bit as much as I would if it had the opposite results. In materials, experiment has always led theory. Theory has use in suggesting new angles to explore with experiment, but theory is fundamentally reactive: get new data, try to fit…

I have little to add other than I f---ing love your spicy take :D ...and agree with most of it. Yeah ofc I know results lead theory in all physics esp materials... :) Disagree re: the not getting how science works, though you might be facetious?... the fact that it just so happens that if you plug the numbers obtained by experimentation into a current reasonable model , HUH, SOMETHING INTERESTING! That's huge. No, I…

> Disagree re: the not getting how science works, though you might be facetious?

Mostly tipsy facetiousness. I mostly wanted to mock the people who thought the DFT analysis was strong evidence that LK-99 is actually a superconductor. Of course, real-life theorists (and experimentalists) know that the advance of science is a progressive dialog between the two groups.

> Can you expand more about what you mean by "the politics here"?

Politics in the sense of getting (positive) recognition. It's absolutely possible for someone to use theory to hypothesize whether LK-99 is a superconductor (RTP or otherwise), and that attempt provides useful predictive value. But someone posting a negative result from that faces more risks than a positive result: the positive case always has an escape hatch (e.g. other factor wasn't accounted for). Experimentalists are lucky, in that escape hatches--e.g. the exact method to reproduce wasn't known to us--are always available to the negative case, because experiments are so messy.

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

#317

Post by [deleted] »

Q6T46nT668w6i3m wrote: post #83
distortionfield wrote: post #28

Earlier quoted context omitted.

It seems more and more like it's credible, but that synthesis is going to prove to be the issue. All these repro attempts are having too much success for there to be nothing behind the team's claims.

Credible? Their claim was “room-temperature superconductivity.”

[deleted]

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

#318

Post by darkvoid00 »

QuadrupleA wrote: post #292
saulrh wrote: post #248

Earlier quoted context omitted.

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 tor…

When the heat generation (inefficiency) is the main limiter in the technology, increasing the efficiency improves performance, rather than just saving power.

The electric motor limitations come from heat, so increased efficiency = increased strength. That 5-15% + work is what melts the motor when going beyond the rated load. I'm not familiar with the superconductors/electrical engineering but I think if no work is performed (motor is stalled), the motor will not get hot, basically just acting as a magnet.

From what I understand it is the same with computer chips, the biggest obstacle the chip companies have is heat generation; the chip gets too hot with the smaller designs. So less heat generation = faster chip.

Autonomous drones (for delivery and stuff) are extremely limited by the very low battery life. They fly around for 20 minutes and are done. Any complication and the battery runs out. So higher efficiency = longer battery life = more capabilities.

Nuclear fusion reactors also apparently benefit from higher temperature superconductors because it is hard to keep them so cold in a reactor. I know nothing about that though. To me it seems like 100 K or 300 K are very different from 100m K regardless but idk lol.

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

#319

Post by goodbyesf »

oska wrote: post #313
loxias wrote: post #290

Earlier quoted context omitted.

[flagged]

> a Chinese or Russian lab claiming something and posting to twitter has very little value Why the national specificity here ?

You know why. The guy probably rants about the ccp or putin every day. Sound like anyone you know? I wish dang would do better handling the obvious rampant flamebait.

@dang flamebait alert. Please climb up thread to find the offending party.

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

#320

Post by cthalupa »

scarmig wrote: post #305
loxias wrote: post #290

Earlier quoted context omitted.

[flagged]

Spicy take: Theory is shit (betraying my bias here). If someone released a paper that theoretically proved a material was a superconductor from first principles, I would ignore it, every bit as much as I would if it had the opposite results. In materials, experiment has always led theory. Theory has use in suggesting new angles to explore with experiment, but theory is fundamentally reactive: get new data, try to fit…

>Honestly, I think anyone who thought the DFT-based papers mattered at all doesn't really get how science works.

It's a very spicy take to say DFT-based papers don't matter at all. Anyone who thinks they conclusively prove or even provide particularly strong evidence that LK99 IS a RTAPS or a superconductor at all is misunderstanding, of course, but there's a lot of room between "doesn't matter at all" and "doesn't provide strong or conclusive evidence"

They propose some theoretical ways in which LK99 COULD be an RTAPS. If we couldn't even come up with theoretical ways it could do so, then that is obviously a bad thing for the idea that LK99 could be a superconductor.

I agree with your general sentiment, just not the level of it.

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