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Semiconducting Transport in LK99 reproduction attempt

arxiv.org

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Re: Semiconducting Transport in LK99 reproduction attempt

#241

Post by pjc50 »

techdragon wrote: post #142
djtango wrote: post #131

Earlier quoted context omitted.

We also don't have a culture of replication. Basically all of the post docs I worked with in the lab lamented how hard it can be to replicate reported syntheses in chemistry wet labs. Everything from humidity and altitude to undocumented "magic tricks" (eg baking something in an oven under vaccuum for a week to get.rid.of.all.the.water.) I heard anecdotes that experiments were sometimes literally only reproducible in…

The simple truth is we don’t have a culture of replication because no one is paying and no one is paying because no one is demanding it as part of the incentive system that the money is part of… If a prerequisite of publication in a top tier journal was someone having replicated the work… anyone at all… then the quality of write up would improve dramatically because all the stuff that never gets written up would be w…

> The simple truth is we don’t have a culture of replication because no one is paying and no one is paying because no one is demanding it as part of the incentive system that the money is part of…

A darker comment: the non-replication of results implies that nobody's actually making use of the science output, and an alarmingly large fraction of unreplicated positive results are simply a waste of time.

Re: Semiconducting Transport in LK99 reproduction attempt

#242

Post by mrtranscendence »

AYBABTME wrote: post #133
bibabaloo wrote: post #52

Earlier quoted context omitted.

There's betting markets on this, aren't there? The super cynical take is that the original scientists know that it's a fraud but in the lead up to it being proven as fraud can make a lot of money before coming out and saying "sorry, we messed up, experimental errors etc etc"

How are they going to make money with this? A few weeks of buzz isn't going to make anyone rich. It's not like they're going for some product placement along with the buzz.

I guess they could bet heavily against themselves, try to get prediction markets to coalesce around the result being genuine, them come out saying "oops, we were mistaken"? Bam, rich!

Re: Semiconducting Transport in LK99 reproduction attempt

#243

Post by paulmd »

djtango wrote: post #131
dmvdoug wrote: post #106

Earlier quoted context omitted.

Not just materials science though. I’m a longtime reader of Derek Lowe’s In the Pipeline blog, and he often emphasizes the trickiness of lab work and lab techniques. But the model we have of science from elementary and high school doesn’t give us room for the random, ephemeral things that come into play in actual experimental work. Our model is methods equal result, every time, even though jiggling your foot a little…

We also don't have a culture of replication. Basically all of the post docs I worked with in the lab lamented how hard it can be to replicate reported syntheses in chemistry wet labs. Everything from humidity and altitude to undocumented "magic tricks" (eg baking something in an oven under vaccuum for a week to get.rid.of.all.the.water.) I heard anecdotes that experiments were sometimes literally only reproducible in…

> baking something in an oven under vaccuum for a week to get.rid.of.all.the.water.

vacuum oven also works great for drying 3d printer filament!

Re: Semiconducting Transport in LK99 reproduction attempt

#244

Post by paulmd »

lolinder wrote: post #222
guerrilla wrote: post #190

Earlier quoted context omitted.

> It just seems strange to simultaneously claim to have discovered something 24 years ago, and to have been rushed into publishing prematurely. They had to get other jobs to survive. Somone else forced their hand with the publication. There's nothing incosistent about that.

There was no one who would be willing to fund their research into a room temperature semiconductor? Even though they had a sample that passed the basic tests?

the world is filled with quacks looking for funding for superconductor research, I can definitely imagine that 20 years ago it would have been difficult to find funding for blue-sky research in superconductivity even with a modest amount of evidence in-hand

Re: Semiconducting Transport in LK99 reproduction attempt

#245

Post by [deleted] »

cthalupa wrote: post #180
jboggan wrote: post #179

I think this theoretical result by Griffin at the Livermore Lab explains why labs are having difficulty replicating the LK-99 sample: https://arxiv.org/pdf/2307.16892.pdf There are basically two repeating crystal cells. Her theoretical calculation shows superconducting properties when you substitute one cell for copper, but not the other. The "bad" substitution is a lower energy substitution that occurs more easily.…

Her* But the paper is exciting, particularly with people now independently recreating the diamagnetic effect.

[deleted]

Re: Semiconducting Transport in LK99 reproduction attempt

#246

Post by roywiggins »

faraggi wrote: post #113
regular_trash wrote: post #104

Earlier quoted context omitted.

This assumes the chemical structure is stable, which may not be the case. If the material is truly not superconductive at room temperature, it will take a long time to gather enough diverse experimental evidence to build a scientific consensus. A good rule of thumb is probably 3 months to reproduce, 6 months to discredit.

why is it slower to discredit than to reproduce?

If I can replicate a result, that's fairly straightforward: I replicated it!

If I can't, that doesn't mean the result was necessarily wrong; maybe I just messed up, or got unlucky and the result only happens 20% of the time. You might need several independent failed replications to start to be confident that the original result was definitely wrong.

It's like saying: there's a buried treasure in this acre. If I find it on my first pass through with a metal detector, job done. If I don't find it on my first pass, I'll probably need to make several more passes, maybe bring in fancier equipment and so on, before I could be pretty confident that it's not there.

Re: Semiconducting Transport in LK99 reproduction attempt

#247

Post by DannyBee »

mhb wrote: post #196
DannyBee wrote: post #189

Earlier quoted context omitted.

The thing is - there is a totally easy and simple mechanism to create early-stage believability. Take a video of you producing and testing it, with a mobile phone. It only works 10% of the time? Not an issue, post 10 videos. Whatever. Would it be perfect? No, of course it could be faked. But i guaranteed people would be a ton less skeptical and willing to push hard on this if the original authors had done this sort o…

Are you suggesting that they take phone video of all their experiments over the course of multiple years? Or just the one they know will succeed?

I'm sorry, you really think it's that hard to have a camera running in a lab that records footage continuously, and you save the clips where you succeed?

What percent of the cost of running these experiments do you think that is to buy a nest or a unifi camera? Heck, Do you believe the university doesn’t already have a surveillance system almost certainly in the hallway to the lab. Plenty of them even have cameras in every lab already. In the past two weeks, I was in three material science labs in Georgia, and South Carolina and all of them had cameras in every lab.

This is not that hard. If you wanna argue that it’s not helpful, that’s one thing. But arguing that it is difficult seems very silly.

Re: Semiconducting Transport in LK99 reproduction attempt

#248

Post by DannyBee »

bluGill wrote: post #191
DannyBee wrote: post #189

Earlier quoted context omitted.

The thing is - there is a totally easy and simple mechanism to create early-stage believability. Take a video of you producing and testing it, with a mobile phone. It only works 10% of the time? Not an issue, post 10 videos. Whatever. Would it be perfect? No, of course it could be faked. But i guaranteed people would be a ton less skeptical and willing to push hard on this if the original authors had done this sort o…

Production takes more than a day - I don't know of any phone that can take videos lasting that long (if people are even willing to watch it). You can of course take several videos and splice them together. Worse yet, I can with a bit of trick photography and standard liquid nitrogen cooled super conductors make a video that looks like success even though I'm working with colored wax for materials in the production pr…

Ignore mobile phones, put in a nest, whatever.

It is not that hard or expensive to record footage for a few days at a time having a continuous overwrite.

You likely don't even need to go that far -Most universities have cameras everywhere, anyway, including plenty of universities that have cameras in every lab of this kind.

It is also done by millions of home users all the time.

As I said, yes, things can be faked, but who cares that’s not the point

Re: Semiconducting Transport in LK99 reproduction attempt

#249

Post by DannyBee »

bckr wrote: post #221
DannyBee wrote: post #189

Earlier quoted context omitted.

The thing is - there is a totally easy and simple mechanism to create early-stage believability. Take a video of you producing and testing it, with a mobile phone. It only works 10% of the time? Not an issue, post 10 videos. Whatever. Would it be perfect? No, of course it could be faked. But i guaranteed people would be a ton less skeptical and willing to push hard on this if the original authors had done this sort o…

People are plenty motivated, it only came out a few days ago and there’s a replication attempt. As others have pointed out the idea of using video as strong evidence is underbaked.

Which is why the top thread is now replication videos?

I didn’t say strong evidence, I said evidence.I was, in fact, quite clear that it is not strong evidence. you seem to have added that so that you could be more dismissive.

Re: Semiconducting Transport in LK99 reproduction attempt

#250

Post by mrguyorama »

canjobear wrote: post #46
TillE wrote: post #31

Earlier quoted context omitted.

They mention the possibility of a mistake when measuring resistivity, which has already been discussed. But yeah, the partial levitation is not a mistake. Their abstract suggests LK-99 is a "highly insulating diamagnet", but they are not even able to "detect any reliable diamagnetic signal" with their instruments. I'd rank the possibilities as: fraud, a different material, or some comical series of bizarre mistakes a…

If it’s fraud, what’s the end game?

If it's fraud, this would be the second time a South Korean scientist has tried to lie about work that revolutionizes a field
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