Since Halloween is upon us, The Royal Institution has found a pretty novel way of celebrating: exploding pumpkins and the eerie powers of superconductor levitation.
The first video shows a jack-o'-lantern bursting with a thermite reaction between iron oxide and aluminum powder. The reaction needs a lot of energy to get going, so it’s all started by lighting a piece of magnesium ribbon which creates a high temperature. They also stuffed the bottom pumpkin with some gun cotton because, you know, science.
The second Halloween-themed video shows the power of superconductors and their ability to levitate a small pumpkin off a track. It’s all to do with the strong magnets in the track and a curious property of superconductors: magnetic fields don't penetrate them, so you can keep an object in a magnetic force field. Anyway, let Andy Marmery explain it for you.