Transparent Metal Hints at Nature of Planets’ Cores

Transparent aluminium, a sci-fi material brought to 20th century Earth by the crew of The Enterprise in Star Trek IV: The Voyage Home, turns out to exist after all — if you see in X-rays. To create this exotic state of matter, researchers at the FLASH facility in Hamburg, Germany, took a thin piece of aluminium foil and blasted it with an X-ray laser that can generate about 10 million gigawatts of power per square centimetre. At standard temperature and pressure, solid aluminium is a lattice of ions, with a sea of free electrons in between. The FLASH beam had enough energy to knock an electron out of each ion and set it free, while the photon got absorbed in the process