6 ms·

the original poster said that this video was sent to him by a fellow researcher who received it on telegram from 'a colleague'. no further details given. if thi

the original poster said that this video was sent to him by a fellow researcher who received it on telegram from 'a colleague'. no further details given. if this is truly lk99 showing flux pinning, then that would be very strong evidence that it's also a superconductor. (physics bsc here, my only experience with condensed matter is 1 course and nothing more)

dTal 3y ago
You can observe the Meissner effect using an ordinary pencil lead, so I wouldn't call it "very strong evidence": https://www.youtube.com/watch?v=yeIizmhzPQc https://www.youtube.com/watch?v=yeIizmhzPQc
- dtx1 3y ago
  No, thats just diamagnetism not the meissner effect
  - alchemist1e9 3y ago
    Is there anything in these videos that is unique to meissner effect? in others words why can’t it be diamagnetism?
    - dtx1 3y ago
      It looks (could be faked) like flux pinning is happening. Essentially, it's not moving but staying in place. Imagine trying to balance a magnet on another. It would not inherently stay in place.
    - mitthrowaway2 3y ago
      It looks like that permanent magnet it's hovering over is a simple dipole magnet, rather than an array. A diamagnet would be unstable in that position. Look at any video of floating graphite and you'll see it hovering on top of a 2x2 array of magnets. Of course, you could fake it for a video by buying a special disc magnet with a multipolar magnetization pattern, but magnets like that are pretty hard to find.
      - s1artibartfast 3y ago
        Putting a conspiracy cap on, is relatively easy to find a cover for an array that looks like a magnet
      - thetoon 3y ago
        > but magnets like that are pretty hard to find. Though, so far, room temperature superconductors have been even harder.
      - regularfry 3y ago
        If you already had a multipolar magnet for some reason, on the other hand, this wouldn't be too far fetched. You've got to think that with all the interest in this right now, the confluence of having access to a handy collection of peculiar magnets, knowing what to do with a bit of graphite, and being enough of a troll to publish a video, all in a single individual, isn't going to be that unlikely.
    - typon 3y ago
      Yes - Meissner effect is also called Flux Pinning. Superconductor will remain pinned to the magnet in any orientation. Diamagnet will only repel. The video shows horizontal hover - that confirms Meissner effect.
      - deleted 3y ago
        [deleted]
      - floxy 3y ago
        Flux Pinning is separate from the Meissner effect. Flux pinning only happens in Type II superconductors, where the Meissner effect of expelling external magnetic fields happens with both Type I and Type II superconductors. https://en.wikipedia.org/wiki/Flux_pinning https://en.wikipedia.org/wiki/Flux_pinning https://en.wikipedia.org/wiki/Meissner_effect https://en.wikipedia.org/wiki/Meissner_effect
        xorbax 3y ago
        Meissner and flux pinning have to be mutually-exclusive, so so do we know the transition condition in LK99? NB: This may be painfully obvious from the figures.
toomanyrichies 3y ago
[flagged]

dTal 3y ago

You can observe the Meissner effect using an ordinary pencil lead, so I wouldn't call it "very strong evidence": https://www.youtube.com/watch?v=yeIizmhzPQc https://www.youtube.com/watch?v=yeIizmhzPQc

dtx1 3y ago
No, thats just diamagnetism not the meissner effect
- alchemist1e9 3y ago
  Is there anything in these videos that is unique to meissner effect? in others words why can’t it be diamagnetism?
  - dtx1 3y ago
    It looks (could be faked) like flux pinning is happening. Essentially, it's not moving but staying in place. Imagine trying to balance a magnet on another. It would not inherently stay in place.
  - mitthrowaway2 3y ago
    It looks like that permanent magnet it's hovering over is a simple dipole magnet, rather than an array. A diamagnet would be unstable in that position. Look at any video of floating graphite and you'll see it hovering on top of a 2x2 array of magnets. Of course, you could fake it for a video by buying a special disc magnet with a multipolar magnetization pattern, but magnets like that are pretty hard to find.
    - s1artibartfast 3y ago
      Putting a conspiracy cap on, is relatively easy to find a cover for an array that looks like a magnet
    - thetoon 3y ago
      > but magnets like that are pretty hard to find. Though, so far, room temperature superconductors have been even harder.
    - regularfry 3y ago
      If you already had a multipolar magnet for some reason, on the other hand, this wouldn't be too far fetched. You've got to think that with all the interest in this right now, the confluence of having access to a handy collection of peculiar magnets, knowing what to do with a bit of graphite, and being enough of a troll to publish a video, all in a single individual, isn't going to be that unlikely.
  - typon 3y ago
    Yes - Meissner effect is also called Flux Pinning. Superconductor will remain pinned to the magnet in any orientation. Diamagnet will only repel. The video shows horizontal hover - that confirms Meissner effect.
    - deleted 3y ago
      [deleted]
    - floxy 3y ago
      Flux Pinning is separate from the Meissner effect. Flux pinning only happens in Type II superconductors, where the Meissner effect of expelling external magnetic fields happens with both Type I and Type II superconductors. https://en.wikipedia.org/wiki/Flux_pinning https://en.wikipedia.org/wiki/Flux_pinning https://en.wikipedia.org/wiki/Meissner_effect https://en.wikipedia.org/wiki/Meissner_effect
      - xorbax 3y ago
        Meissner and flux pinning have to be mutually-exclusive, so so do we know the transition condition in LK99? NB: This may be painfully obvious from the figures.

toomanyrichies 3y ago

[flagged]