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That video reminds me of the way pyrolytic graphite floats on strong magnets. https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html https://scito

That video reminds me of the way pyrolytic graphite floats on strong magnets. https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphi... https://youtu.be/Wk3seHNmNs8 https://youtu.be/Wk3seHNmNs8

eig 3y ago
Yep, that’s strong diamagnetism.
littlestymaar 3y ago
The common point being that it levitates, at room temperature (so no cryogenic fumes on the video), but that's exactly what you'd expect from a room-temperature SC… The big difference between your graphite video and the one from yesterday is that the later doesn't move, whereas the former never rests.
- XorNot 3y ago
  The problem with the video we see is that the sample never actually levitates - one side is touching the magnet. So a regular diamagnetic material, with enough weight on one side, would display the same effect. In this video shortly after this moment you see something very similar looking with pyrolytic carbon: https://youtu.be/VC3r9-OaWes?t=133 https://youtu.be/VC3r9-OaWes?t=133
scythe 3y ago
It's true that pyrolytic graphite does this, but it's also worth noting that pyrolytic graphite is one of a very few materials that has such a strong conventional diamagnetism: the list includes pyrolytic graphite and metallic bismuth and ends there. I have actually searched the literature for such materials on a few occasions simply because they seem like they would make a fun decoration, and PG (and "highly oriented" PG) is pretty much the only one (bismuth is too dense).
- mitthrowaway2 3y ago
  Definitely. Discovering another material besides pyrolytic graphite that exhibits strong enough diamagnetism to levitate wouldn't get your name in the history books like room-temperature superconductivity would, but it would already be a major career-making discovery, with at least enough commercial value to launch a niche company. It would be very strange to tarnish your reputation with fraudulent, easily-refuted claims of superconductivity if you've already achieved such a breakthrough.
zbobet2012 3y ago
As far as I am aware you need multiple magnets to make this happen, just one will cause it to "fall" off. In the video it's just one magnet, and it doesn't try to "slide" away when it's moved past the edge of the magnet. That's a strong indicator of quantum locking. I am not an expert in this field though. https://www.imagesco.com/magnetism/graphite-levitation-kit.html https://www.imagesco.com/magnetism/graphite-levitation-kit.h... https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphi...
- SiempreViernes 3y ago
  They don't show the actual field of the big metallic cylinder, so you can't rule out a situation as shown at the start of this video: https://youtu.be/D-tW8_SRW3g https://youtu.be/D-tW8_SRW3g where two identically looking objects are revealed to have very different magnetic fields. Whether it makes sense to say the multipole magnet is "multiple magnets" is a philosophical debate in itself.

eig 3y ago

Yep, that’s strong diamagnetism.

littlestymaar 3y ago

The common point being that it levitates, at room temperature (so no cryogenic fumes on the video), but that's exactly what you'd expect from a room-temperature SC… The big difference between your graphite video and the one from yesterday is that the later doesn't move, whereas the former never rests.

XorNot 3y ago
The problem with the video we see is that the sample never actually levitates - one side is touching the magnet. So a regular diamagnetic material, with enough weight on one side, would display the same effect. In this video shortly after this moment you see something very similar looking with pyrolytic carbon: https://youtu.be/VC3r9-OaWes?t=133 https://youtu.be/VC3r9-OaWes?t=133

scythe 3y ago

It's true that pyrolytic graphite does this, but it's also worth noting that pyrolytic graphite is one of a very few materials that has such a strong conventional diamagnetism: the list includes pyrolytic graphite and metallic bismuth and ends there. I have actually searched the literature for such materials on a few occasions simply because they seem like they would make a fun decoration, and PG (and "highly oriented" PG) is pretty much the only one (bismuth is too dense).

mitthrowaway2 3y ago
Definitely. Discovering another material besides pyrolytic graphite that exhibits strong enough diamagnetism to levitate wouldn't get your name in the history books like room-temperature superconductivity would, but it would already be a major career-making discovery, with at least enough commercial value to launch a niche company. It would be very strange to tarnish your reputation with fraudulent, easily-refuted claims of superconductivity if you've already achieved such a breakthrough.

zbobet2012 3y ago

As far as I am aware you need multiple magnets to make this happen, just one will cause it to "fall" off. In the video it's just one magnet, and it doesn't try to "slide" away when it's moved past the edge of the magnet. That's a strong indicator of quantum locking. I am not an expert in this field though. https://www.imagesco.com/magnetism/graphite-levitation-kit.html https://www.imagesco.com/magnetism/graphite-levitation-kit.h... https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html https://scitoys.com/scitoys/scitoys/magnets/pyrolytic_graphi...

SiempreViernes 3y ago
They don't show the actual field of the big metallic cylinder, so you can't rule out a situation as shown at the start of this video: https://youtu.be/D-tW8_SRW3g https://youtu.be/D-tW8_SRW3g where two identically looking objects are revealed to have very different magnetic fields. Whether it makes sense to say the multipole magnet is "multiple magnets" is a philosophical debate in itself.