This is coolest thing we've seen in a long time:
The video was posted to YouTube two days ago by the Association of Science-Technology Centers and has already garnered 641,230 views. But what is going on here? It's quantum levitation, dude!
This levitation effect is explained by the Meissner effect, which describes how, when a material makes the transition from its normal to its superconducting state, it actively excludes magnetic fields from its interior, leaving only a thin layer on its surface.
When a material is in its superconducting state — which involves very low temperatures — it is strongly diamagnetic. This means that when a magnetic field is externally applied, it will create an equally opposing magnetic field, locking it in place.