Quantum Levitation
Why Hacker News recommends it
Linked in superconductivity and levitation threads as the canonical quantum locking demo.
What it is
A short demo from Tel-Aviv University of a superconductor locked in a magnetic field, hovering and staying fixed in place. It was shown at the 2011 ASTC conference.
Recommended by 0 HN commenters across 0 different months, 2012 to 2023.
What Hacker News said
Cites pwang · 2012-05 · on “ZeroN system holds a ball wherever you place it, in mid-air”
Oh, they do this with classical electromagnets and computer vision. Lame. I thought this was going to be a quantum spin locking demo at large distances (>10cm): [this video]
Cites xauronx · 2014-03 · on “HUVr Board”
I'm sure you've seen this, but I was REALLY hoping the video was some kind of large scale riff on this: [this video] Related: [LINK] And more awesome: [LINK] It's already 3 years old, so I'm waiting for people to use this technology or an extension of it for something cool.
Cites jonmrodriguez · 2016-01 · on “How to Investigate a Flying Saucer”
I feel like part of the cultural fascination with flying saucers is that we intuitively feel like it should be possible for someone with advanced technology to levitate without expending power. We are starting to get there, with quantum locking, which can levitate a type-II superconductor relative to a supporting magnetic field. [this video] [LINK] I wonder if it would be physically possible to utilize the Earth's extremely weak magnetic field to support any meaningful mass?
Cites sxp · 2020-11 · on “Earnshaw's Theorem”
The other interesting loophole is [LINK] which gives you levitating superconductors and (impractical) hovercars: [this video]
Cites trgern · 2023-07 · on “Room Temperature, Ambient Pressure Superconductivity–This Time for Real?”
The video of “levitation” is one of the things that makes me, a complete ignoramus of the subject matter, skeptical. [LINK] All other instances of “quantum levitation” that I have seen has a “locked in” effect: [this video] . Whereas the material in this video seems to bounce and warble in a way that appears to me more akin to standard static or magnetic repulsion. Hope I’m wrong.
Cites uyhgr · 2023-08 · on “LK99: Team of Southeast University observed zero resistance below 110 K”
Correct, the imperfections of the crystal allowing the flux pinning permits even a “hanging levitation”. Here is a timestamped video showing that: [this video] 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.