3 ms·
It is clearly resting on the magnet. I don't know the mechanics off the top of my head, but that is enough mechanical constraint for a pair of permanent magnets
by whatshisface 3y ago
It is clearly resting on the magnet. I don't know the mechanics off the top of my head, but that is enough mechanical constraint for a pair of permanent magnets to levitate.
- willis936 3y agoIt isn't. Permanent magnets would be unstable. This would have to be a diamagnetic or superconducting material.
- IshKebab 3y agoIt is, depending on how big the contact patch is. But does look pretty small in this video and it doesn't really behave like a permanent magnet would.
- deleted 3y ago[deleted]
- jeepers6 3y agoSuperdiamagnetism occurs primarily in superconductors. Reminder that flux-pinned levitation only occurs when superconductors are cooled from above to below their critical temperature while in a local magnetic field. The researchers probably didn’t heat up their big sample above the critical temperature in air as that could have mechanically destroyed it. It was already chipped almost in two.
- mitthrowaway2 3y ago> Reminder that flux-pinned levitation only occurs when superconductors are cooled from above to below their critical temperature while in a local magnetic field. Casual demonstrations of levitating superconductors involve first submerging the superconducting material in a (non-magnetized) tub of LN2, and then moving it onto a magnetic track. For example, https://www.youtube.com/watch?v=X5EoUD-BIss https://www.youtube.com/watch?v=X5EoUD-BIss
- jeepers6 3y agoThat’s true, surprising to hear that the YBCO SC in that video is only 30um think.
- sockaddr 3y agoI’m not convinced it’s levitating in the video, imagine a magnetic field strong enough to partially lift the fleck but also a patch of the fleck contacting the magnet with enough friction to keep it from sliding away.