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Andrew McCalip demonstrates synthesis of LK99

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Re: Andrew McCalip demonstrates synthesis of LK99

#331

Post by codethief »

anonylizard wrote: post #112
DoingIsLearning wrote: post #60

Earlier quoted context omitted.

The first pre-print came out on 22 July (if I am not mistaken). Not enough time has passed pure and simple. If I was an academic working on this, I would be following the Sagan Standard and triple checking my results before claiming anything. I think we are all suffering from 24 hour news cycles. The work in China and now Varda is very exciting but they are warp speed developments.

This is simply what post-peer-review looks like. Instead of a few anonymous peer reviews, you get the entire planet to replicate. Moment you get something meaningful, publish it on arxiv. Quantity, not quality is king. Anomalies are drowned out by large samples. Questionable methods get mass debated in public. Scientists are dependent on public funding, why squander the biggest moment in pop science for literal decad…

> Instead of a few anonymous peer reviews, you get the entire planet to replicate.

Notably, peer reviews typically don't involve reviewers trying to replicate the results. So we've essentially skipped peer review (at least temporarily) and went full speed ahead with the post-peer-review process.

Re: Andrew McCalip demonstrates synthesis of LK99

#332

Post by marcosdumay »

jcranmer wrote: post #329
marcosdumay wrote: post #328

Earlier quoted context omitted.

It's pretty much due to the strength of evidence. There is no conclusive proof that this is a superconductor on the replications, but the evidence has been on a different level from nearly everything else you'll find on Arxiv since the beginning.

AIUI, things that float in a magnetic field at ~room temperature are moderately common claims, and this is really the only evidence that LK-99 might be a room-temperature superconductor. The published ancillary evidence in the original paper actually raises red flags that isn't a superconductor--the "0 resistivity" domain in their temperature-dependent resistivity plot is (when you realize the units they're using) ac…

> things that float in a magnetic field at ~room temperature are moderately common claims

At monopolar magnetic fields weak enough to come from a permanent magnet is a lot rarer.

Almost all superconductor claims come from measuring magnetic resonance or direct resistance measurements. Both are noisy things to measure, and won't get you reliable results.

Re: Andrew McCalip demonstrates synthesis of LK99

#333

Post by [deleted] »

ThePhysicist wrote: post #212

Honestly I don't see anything that would prove superconductivity in this video. If LK-99 is a type-II superconductor you should observe flux pinning i.e. you would be able to move the flake with a tweezer and it would be stuck in place as the magnetic flux lines are pinned to defects in the material. I haven't seen any details on the supposed properties of the material like the coherence length, but from the original…

[deleted]

Re: Andrew McCalip demonstrates synthesis of LK99

#334

Post by brakedam »

kijin wrote: post #330
brakedam wrote: post #310

Earlier quoted context omitted.

But I heard that in the interview, Dr. Kim said they have various samples that have different magnetization properties. It doesn’t make sense that they have only a few samples, ironically. I’m sorry, but this makes me think that they are trying to move the public some other way.

Judging from the Korean-language interviews making the rounds today, there seems to be some sort of political tension between the researchers and the so-called verification committee. There's disagreement about whether anyone actually demanded samples, or whether it was just a polite request... I have a hunch that this might have something to do with the late professor Chair (Choi?) who came up with the idea back in…

Now I understand what's going on in South Korea. Okay, this is more political than I thought. But the problem is, the researchers even didn't send the sample abroad to prove it. Even though they had many requests for a week. This doesn't make sense, and that kind of background story is not helpful in solving this.

Re: Andrew McCalip demonstrates synthesis of LK99

#335

Post by sixQuarks »

dvh wrote: post #129
timinou wrote: post #99

I'm curious what companies stand to gain the most from this discovery... I understand the promises of LK-99, but where do you think where we'll see it be applied first?

$9 floating superconductor toy on AliExpress, free shipping

Lol. You’re probably right

Re: Andrew McCalip demonstrates synthesis of LK99

#336

Post by cthalupa »

username332211 wrote: post #260
kijin wrote: post #213

Earlier quoted context omitted.

It's the same in Korea where the research originated. A bunch of professors belonging to a hastily formed academic committee are trying to monopolize the public debate, quibbling about errors in the arxiv paper and demanding that Lee & Kim turn over samples of LK-99 because the big-name professors are obviously too busy to make their own. It seems that their first priority is to avoid a repeat of the Hwang scandal th…

Any time the material exhibits a properties inconsistent with superconductors, the to-go explanation is that it's supposedly extremely difficult to manufacture. Not to mention, the original instructions include stuff like "The sealed tube containing the mixed powder was heated in a furnace at 925°C for 5-20 hours." which sounds a tad bit imprecise. Don't you think in those conditions it's at least a little bit reason…

>Don't you think in those conditions it's at least a little bit reasonable to demand samples?

No. Because ultimately they don't owe anyone anything outside of the standard scientific process. They want to get the peer reviewed article published, and have stated that if people still want samples after that they will provide them.

Half of twitter shitposting about FLOAT THE ROCK and a bunch of curious scientists and engineers attempting to replicate this doesn't fundamentally change this equation. If it's a superconductor now, it'll be a superconductor in 6 months.

None of the media hype or unwashed masses treating this as science entertainment should significantly impact the process they are going through. Assuming they've got an RTAPS, they'll get the Nobel Prize regardless of whether or not they satisfy everyone's curiosity right this moment or a year from now. Assuming they don't have one, well, that'll get found out too.

Re: Andrew McCalip demonstrates synthesis of LK99

#337

Post by Accujack »

anonylizard wrote: post #112
DoingIsLearning wrote: post #60

Earlier quoted context omitted.

The first pre-print came out on 22 July (if I am not mistaken). Not enough time has passed pure and simple. If I was an academic working on this, I would be following the Sagan Standard and triple checking my results before claiming anything. I think we are all suffering from 24 hour news cycles. The work in China and now Varda is very exciting but they are warp speed developments.

This is simply what post-peer-review looks like. Instead of a few anonymous peer reviews, you get the entire planet to replicate. Moment you get something meaningful, publish it on arxiv. Quantity, not quality is king. Anomalies are drowned out by large samples. Questionable methods get mass debated in public. Scientists are dependent on public funding, why squander the biggest moment in pop science for literal decad…

>This is simply what post-peer-review looks like.

No, this is a new face for peer review. Existing peer review processes have stagnated in the information age, possibly with good reason. There are a lot of advantages to more immediate review of papers and data, and also to bypassing the systems of qualifications presently used to choose who is a valid reviewer.

Re: Andrew McCalip demonstrates synthesis of LK99

#338

Post by cthalupa »

brakedam wrote: post #334
kijin wrote: post #330

Earlier quoted context omitted.

Judging from the Korean-language interviews making the rounds today, there seems to be some sort of political tension between the researchers and the so-called verification committee. There's disagreement about whether anyone actually demanded samples, or whether it was just a polite request... I have a hunch that this might have something to do with the late professor Chair (Choi?) who came up with the idea back in…

Now I understand what's going on in South Korea. Okay, this is more political than I thought. But the problem is, the researchers even didn't send the sample abroad to prove it. Even though they had many requests for a week. This doesn't make sense, and that kind of background story is not helpful in solving this.

It would not be a normal part of the process for people to be demanding samples just because there was a preprint posted on arxiv. It's a weird situation and they don't owe anyone any of these samples.

They say they want to share samples after they get a peer reviewed paper published. That's not a weird position to be in. If it wasn't for the hype around this, they wouldn't be in this position.

Let the process play out like it normally does, and if none of the replication attempts pan out, they can provide the samples after the peer review. We'll still care about RTAPS even if it takes another year for a sample to be provided.

Re: Andrew McCalip demonstrates synthesis of LK99

#339

Post by pnwcoder »

ThePhysicist wrote: post #212

Honestly I don't see anything that would prove superconductivity in this video. If LK-99 is a type-II superconductor you should observe flux pinning i.e. you would be able to move the flake with a tweezer and it would be stuck in place as the magnetic flux lines are pinned to defects in the material. I haven't seen any details on the supposed properties of the material like the coherence length, but from the original…

What would be an explanation for the partial levitation of the LK-99 sample shown in the video?

Re: Andrew McCalip demonstrates synthesis of LK99

#340

Post by ThePhysicist »

pnwcoder wrote: post #339
ThePhysicist wrote: post #212

Honestly I don't see anything that would prove superconductivity in this video. If LK-99 is a type-II superconductor you should observe flux pinning i.e. you would be able to move the flake with a tweezer and it would be stuck in place as the magnetic flux lines are pinned to defects in the material. I haven't seen any details on the supposed properties of the material like the coherence length, but from the original…

What would be an explanation for the partial levitation of the LK-99 sample shown in the video?

Could be normal diamagnetism, or even ferromagnetism. Very hard to say as they don't even give any field strengths in the video, it's just a Neodym magnet they hold near the sample. If I understand the video correctly they just orient the magnet by hand, so I would not even rule out a ferromagnetic effect. There can be multiple regions with different orientation in such a polycristalline material, which can produce all kinds of weird effects. Not saying that it's not a superconductor, just that I would not draw any conclusions from this video. If this was a type-II superconductor and the flux pinning is strong enough to lift the flake up you should be able to drag it across the bottom of the beaker with the magnet as the magnetic flux lines "impale" the crystal, i.e. they are in an energy minimum and moving them out of there causes resistance as they need to break the superconductivity in the material surrounding the defect where they are pinned. If it's just diamagnetism that's not the case. So observing that the flake is completely stationary when the magnet is moved in our out tells me this likely isn't flux pinning we're seeing.

I'm a bit skeptical how they even know it's the right material, getting the doping right seemed quite intricate so it would seem quite extraordinary that they can hit the right process after trying for a few days. Not saying they didn't, but so far I'm rather inclined to believe they just got a ferromagnetic metal flake (which is easy to get following the thermal annealing process they did, or even by banging the material up a bit as they seem to have done for getting it out of the synthesis tubes).

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