4 ms·

The term is “flux pinning”, and it only applies to the “quantum lock” effect. That is the specifically static hovering effect. The diamagnetism, importantly th

by uyhgr 3y ago

The term is “flux pinning”, and it only applies to the “quantum lock” effect. That is the specifically static hovering effect. The diamagnetism, importantly this means repulsion of both poles simultaneously and equally (this is how you can have these magnets spin, a regular magnet repels same poles and attracts opposites, diamagnets repel both poles), is simply a characteristic of the superconductor, but it alone would just repel the object off. Here is a timestamped link to NileRed’s YBCO video that visually describes the flux pinning: https://m.youtube.com/watch?v=RS7gyZJg5nc&t=1887 https://m.youtube.com/watch?v=RS7gyZJg5nc&t=1887 And here’s a timestamped link to Ben Krasnow’s Applied Science YBCO video where he shows a close up of the crystal’s cross section that shows the imperfections that allow the magnetic field through for the pinning effect: https://m.youtube.com/watch?v=sLFaa6RPJIU&t=75 https://m.youtube.com/watch?v=sLFaa6RPJIU&t=75

jacquesm 3y ago
NileRed is youtube gold. It's one of very few channels that I follow and learn from.
- faraggi 3y ago
  I agree, great channel, but the cadence in his narration is atrocious.
  - jacquesm 3y ago
    It's fantastic compared to a lot of the people that I interact with on a daily basis so it doesn't bother me.
  - abnry 3y ago
    It only adds to the channel. I find it amusing.
adolph 3y ago
When NileRed puts the YBCO on top of the row of bar magnets and it ping-pongs back and forth is awesome! Timestamp: https://youtu.be/RS7gyZJg5nc?t=2496 https://youtu.be/RS7gyZJg5nc?t=2496
- uyhgr 3y ago
  The best thing about the NileRed superconductor video is it shows him initially failing to reproduce a YBCO superconductor after having already succeeded once before! It goes to show how difficult manufacture, or in the case of the LK-99 news cycle “reproduction”, of these materials really is, and YBCO was a well documented area of superconductor manufacture.
  - jacquesm 3y ago
    And that he doesn't know what went wrong but comes up with a hypothesis and tests it and it works.
Laforet 3y ago
Flux pinning of a superconductor should be able to hold it steady below a magnet, and the magnet should be able to drag the superconductor with it when moving (within reasonable weight limits of course). These will demonstrate for sure that levitation is not simply a force equilibrium between gravity, magnetic repulsion and one corner of the material resting on the surface. There is a video from the Korean team showing LK99 moving when both poles of a large magnet is swung nearby, however the effect was a bit weak to conclusive.
- uyhgr 3y ago
  Correct, the imperfections of the crystal allowing the flux pinning permits even a “hanging levitation”. Here is a timestamped video showing that: https://m.youtube.com/watch?v=Ws6AAhTw7RA&t=90 https://m.youtube.com/watch?v=Ws6AAhTw7RA&t=90 If we develop methods of creating these superconductors with perfect crystal composition then there will only be the repulsion, allowing for levitation in a bowl shaped superconductor, but this “hanging levitation” would be impossible. Perhaps we will develop manufacturing techniques to induce specific imperfections into the material to ensure predictable flux pinning; it seems like a useful, and wildly interesting side effect.

by uyhgr 3y ago

jacquesm 3y ago

NileRed is youtube gold. It's one of very few channels that I follow and learn from.

faraggi 3y ago
I agree, great channel, but the cadence in his narration is atrocious.
- jacquesm 3y ago
  It's fantastic compared to a lot of the people that I interact with on a daily basis so it doesn't bother me.
- abnry 3y ago
  It only adds to the channel. I find it amusing.

adolph 3y ago

When NileRed puts the YBCO on top of the row of bar magnets and it ping-pongs back and forth is awesome! Timestamp: https://youtu.be/RS7gyZJg5nc?t=2496 https://youtu.be/RS7gyZJg5nc?t=2496

uyhgr 3y ago
The best thing about the NileRed superconductor video is it shows him initially failing to reproduce a YBCO superconductor after having already succeeded once before! It goes to show how difficult manufacture, or in the case of the LK-99 news cycle “reproduction”, of these materials really is, and YBCO was a well documented area of superconductor manufacture.
- jacquesm 3y ago
  And that he doesn't know what went wrong but comes up with a hypothesis and tests it and it works.

Laforet 3y ago

Flux pinning of a superconductor should be able to hold it steady below a magnet, and the magnet should be able to drag the superconductor with it when moving (within reasonable weight limits of course). These will demonstrate for sure that levitation is not simply a force equilibrium between gravity, magnetic repulsion and one corner of the material resting on the surface. There is a video from the Korean team showing LK99 moving when both poles of a large magnet is swung nearby, however the effect was a bit weak to conclusive.

uyhgr 3y ago
Correct, the imperfections of the crystal allowing the flux pinning permits even a “hanging levitation”. Here is a timestamped video showing that: https://m.youtube.com/watch?v=Ws6AAhTw7RA&t=90 https://m.youtube.com/watch?v=Ws6AAhTw7RA&t=90 If we develop methods of creating these superconductors with perfect crystal composition then there will only be the repulsion, allowing for levitation in a bowl shaped superconductor, but this “hanging levitation” would be impossible. Perhaps we will develop manufacturing techniques to induce specific imperfections into the material to ensure predictable flux pinning; it seems like a useful, and wildly interesting side effect.