Geometry, light and a wee bit of magic
Many mass-produced everyday products of modern technology would appear to be completely magical to our ancestors: mobile phones, television, computers, electric light, cars, etc. Some devices that are still perceived as magical or mysterious are about to appear in the laboratory and are not so mysterious after all. For example, the first prototype of an electromagnetic cloaking device has been made at Duke university in 2006. This device makes an object invisible to microwave radiation of a single frequency and polarization. Cloaking devices may also be turned into their exact opposite: perfect lenses that can focus electromagnetic waves with unlimited precision. At Harvard University, first vital steps towards levitating objects on the forces of the quantum vacuum have been made. At St Andrews, we observed first indications of artificial black holes in the laboratory, using extremely short light pulses in photonic-crystal fibres. Invisibility devices, quantum forces and optical black holes have two things in common: they represent applications of Einstein's general relativity in Maxwell's electromagnetism and their practical demonstrations are made possible by modern metamaterials. I will try to elucidate the scientific principles acting behind the scenes of such "pure and applied magic".