Earlier quoted context omitted.
50–97% with 90% considered “good.”
It's also worth contextualizing percentages. 90% still means 1 in every 10 parts fails.
It's not always outright failure, but rather different performance binning.
Semiconducting Transport in LK99 reproduction attempt
231–240 of 269 posts
Re: Semiconducting Transport in LK99 reproduction attempt
#232Earlier quoted context omitted.
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…
> 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 I would expect pairs of labs to gang up, with one of them giving the other the details so that they can reproduce the result, and the contents of the publication staying more or less the same. Reason is that everybody wants to prevent others from being…
Oh absolutely, there’s a lot of potential issues with the simple suggestion of requiring replication. I was tempted to write a bunch more to outline strategies and counter strategies from a game theory perspective but realised it was basically unnecessary since it will never happen.
Re: Semiconducting Transport in LK99 reproduction attempt
#233A paper dropped on the 29th examining if their theory of LK99's superconducting mechanism was plausible. The good news that it is. The bad news is that the copper atoms need to end up in the least likely place in the crystal.
Long story short, though the ingredients are easy to find we should expect reproduction to take longer than we first thought.
Re: Semiconducting Transport in LK99 reproduction attempt
#234Earlier quoted context omitted.
> Combined with the slipshod methodology, doesn't this make you feel like it was silly to release the arXiv paper when they did? Well, the LK-99 team agree As I understand it, the 99 in the name is because they first discovered it in 1999. Seems to me that if you didn't manage to nail down the process in 24 years, it's probably time to publish and let someone else have a go.
And if this technology is on the critical path to solving world hunger/curing cancer or ending wars, then those things have been delayed 24 years, and millions of people are dead, all so these guys could have a shot at a paper in Nature. Humans really are selfish sometimes.
Assuming the worst of people is bad for your mental health
Re: Semiconducting Transport in LK99 reproduction attempt
#235Earlier 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?
You make it sound like that is easy while not knowing much about them or their circumstances. There still isn't. Look at their shitty rented lab. Obviously there are aspects to their situation that not everyone here is aware of.
Re: Semiconducting Transport in LK99 reproduction attempt
#236> In addition, when a pressed Pb10-xCux(PO4)6O pellet is located on top of a commercial Nd2Fe14B magnet at room temperature, no repulsion could be felt and no magnetic levitation was observed either. Unless we assume the original paper's authors were straight up lying, it sounds like this paper's author didn't end up with exactly the same material?
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…
When they say "highly insulating diamagnet" they are referring to Pb2SO5 and not the (claimed) LK-99.
It would be interesting to understand if they believe Pb2SO5 would exhibit levitation. I presume they would say so if they did.
Re: Semiconducting Transport in LK99 reproduction attempt
#237Earlier quoted context omitted.
It's also worth contextualizing percentages. 90% still means 1 in every 10 parts fails.
It's not always outright failure, but rather different performance binning.
But the performance binning is a direct result of careful design that goes out of its way to ensure that a subset of failures can still lead to a workable/binnable products.
It's still a failure to produce a part that matches the full design.
Re: Semiconducting Transport in LK99 reproduction attempt
#238Everyone in this thread needs to understand that particularly for materials science, and particularly when there is bad methodology documentation, it is really, really normal for early replication attempts to fail. What works in one lab will often need to be adjusted to work in another, with different equipment, altitude, humidity, all sorts of stuff. Making it even worse, apparently the original team can't even get…
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…
I am not involved in lab work at all, but his "Things I won't work with" posts are wonderful
Re: Semiconducting Transport in LK99 reproduction attempt
#239Everyone in this thread needs to understand that particularly for materials science, and particularly when there is bad methodology documentation, it is really, really normal for early replication attempts to fail. What works in one lab will often need to be adjusted to work in another, with different equipment, altitude, humidity, all sorts of stuff. Making it even worse, apparently the original team can't even get…
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…
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Re: Semiconducting Transport in LK99 reproduction attempt
#240Can anyone ELI5 - Is the compound/material used for LK-99 that unique? Are there other, similar materials that might also have this 'quantum well' quality?