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Successful room temperature ambient-pressure magnetic levitation of LK-99

arxiv.org

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Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#451

Post by blitzar »

TheSpiceIsLife wrote: post #150
someplaceguy wrote: post #141

Earlier quoted context omitted.

It would have been more convincing if you had given real past examples rather than speculative future ones :) Although I'm pretty sure there are plenty that many people can think of, so it doesn't really detract much from your point.

Nuclear weapons. There hasn’t been a full scale war between major powers since.

> There hasn’t been a full scale war between major powers since.

Yet all the major powers have launched multiple, lengthy full scale wars since.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#452

Post by wetmore »

jjallen wrote: post #442
King-Aaron wrote: post #438

Earlier quoted context omitted.

Have you got any back-story on that? I only saw that their team posted it to arxiv, hadn't heard the other drama

A former employee was the first to publish a paper with only three authors. I am surprised you haven't heard about this. Then a few hours later a paper was published with six authors (without one of the original three authors), ostensibly by the core team that has been working on this. There should be much more detail on the Internet if you search for it.

I also hadn't heard about this for what it's worth.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#453

Post by cthalupa »

cthalupa wrote: post #246
leptons wrote: post #230

Earlier quoted context omitted.

It means we won't lose MRIs when the earth finally runs out of helium as they require liquid helium to run the superconductors that generate the magnetic field. We're running out of helium with no way to replenish it. Helium is the only element on the periodic table which is a non-renewable resource on Earth. So MRIs will get much cheaper, and they could end up being as cheap as taking an x-ray today.

Based on our current data LK99 isn't a replacement for helium cooled superconductors for the same reason YBCO and similar aren't - critical current/critical magnetic field aren't in the right ranges for what we need out of MRI machines. I do think it's too early to say one way or the other what all of this ends up looking like, so we might find that purer/larger samples have better properties than what was measured s…

Correction: YBCO and other REBCO can get up to the needed magnetic field strength, other issues are the reasons it's not a good candidate for MRI machines - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5472374/

(Too late for me to edit)

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#454

Post by zepn »

ChuckMcM wrote: post #129

For those experiencing this type of "black swan, but good" event for the first time, it is helpful to recognize that the human tendency to believe that all future "big events" will be dystopian downers, is statistically unsound. For a while I've kept a list of the things that could be "good" swan events, but to be fair I didn't have "room temperature superconductor on that list" :-) Other things that could happen: 1)…

Interested to see your full list!

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#455

Post by wcerfgba »

jjallen wrote: post #432

One somewhat ironic fact of this story is that the rogue former employee perhaps deserves some credit for bringing this thing out into the world. They had been working on this for quite a long time themselves, rightfully so. But now the whole world is working on it and exploring other methods and combinations of materials I would assume (to improve upon the original design and avoid any patents). How long would they…

Exactly, the 99 stands for 1999, so potentially this material has existed for over 20 years and we could have started testing and replication on a much wider scale a decade ago. What benefit have we gained by disseminating this research so slowly?

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#456

Post by cthalupa »

wetmore wrote: post #452
jjallen wrote: post #442

Earlier quoted context omitted.

A former employee was the first to publish a paper with only three authors. I am surprised you haven't heard about this. Then a few hours later a paper was published with six authors (without one of the original three authors), ostensibly by the core team that has been working on this. There should be much more detail on the Internet if you search for it.

I also hadn't heard about this for what it's worth.

It's one of the reasons people were thinking this might not be a fraud.

Nobel prizes are capped to 3 people, and the speculation is that the rogue person published early to try and ensure they were one of the people that received it. No reason for infighting like that if you know it's a hoax.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#457

Post by suby »

jjallen wrote: post #442
King-Aaron wrote: post #438

Earlier quoted context omitted.

Have you got any back-story on that? I only saw that their team posted it to arxiv, hadn't heard the other drama

A former employee was the first to publish a paper with only three authors. I am surprised you haven't heard about this. Then a few hours later a paper was published with six authors (without one of the original three authors), ostensibly by the core team that has been working on this. There should be much more detail on the Internet if you search for it.

Notably, the missing author from the second paper is the rogue employee who published the first paper. The order of the first two authors is the same for both papers.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#458

Post by crote »

frisco wrote: post #312
caconym_ wrote: post #28

Earlier quoted context omitted.

I have heard people much more knowledgeable than me say that measuring true zero resistance is actually quite difficult and takes some degree of specialized equipment, especially with such small samples. That may be part of it.

Right, if our best regular conductors (used in your ohmmeter) are ~10^-8 and superconductivity is (by convention) less than 10^-11, one can see right away the simple regular methods won’t work and some cleverness is needed.

The conductors of your ohmmeter are not that important, though. You can work around that by using four-terminal sensing, and you can of course also calibrate your probes by directly touching them together. Even if your ohmmeter conductors have a resistance of several ohm, you could still get an accurate measurement if your tool has a high enough resolution.

A bigger issue is going to be sample size. A 1mm-diameter 1mm-long rod of silver has a resistance of about 20 μΩ (or 2e-5) at room temperature. That's already getting tricky to measure with lab-grade equipment without pushing insane currents through it, let alone anything even smaller. If you want to measure a 1m-diameter 1m-long silver rod (which would be 0.02μΩ or 2e-8) you could just push a few thousand amps through it and reliably measure that using a household multimeter in the mV range - but do that with a small sample and it'll evaporate.

Re: Successful room temperature ambient-pressure magnetic levitation of LK-99

#460

Post by belter »

King-Aaron wrote: post #438
jjallen wrote: post #432

One somewhat ironic fact of this story is that the rogue former employee perhaps deserves some credit for bringing this thing out into the world. They had been working on this for quite a long time themselves, rightfully so. But now the whole world is working on it and exploring other methods and combinations of materials I would assume (to improve upon the original design and avoid any patents). How long would they…

Have you got any back-story on that? I only saw that their team posted it to arxiv, hadn't heard the other drama

See this: https://news.ycombinator.com/item?id=36953050
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