Technically, that flying saucer to the left there is known as a wingless electromagnetic air vehicle, or WEAV for short. We’ll just scream “UFO!” and run from it in terror, though, if that’s OK.

It’s powered by “magnetohydrodynamics” – a way of propelling vehicles by ionising air with an electrical current then shooting it out at great speed. The thing also spins, to help keep it stable. It is, basically, your archetypal flying saucer.

The dream-machine of the University of Florida scientist Subrata Roy, WEAV will be undergoing test flights…