The Casimir force is a consequence of quantum mechanics, the theory that describes the world of atoms and subatomic particles that is not only the most successful theory of physics but also the most baffling.
The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a “dry glue” effect that enables a gecko to walk across a ceiling.
Now, using a special lens of a kind that has already been built, Prof Ulf Leonhardt and Dr Thomas Philbin report in the New Journal of Physics they can engineer the Casimir force to repel, rather than attact.
The Telegraph recently carried a story about levitation and how it could be used to help nanotechnologists keep "tiny objects from sticking to each other." It can do this by reversing the Casimir force, which causes things to be drawn together in the first place. In theory, this could be used to levitate whole humans and, more importantly, move large objects.