Metallic hydrogen makes its debut, maybe

German scientists claim to have produced a long-sought material

Hydrogen gas squeezed at tremendous pressures has transformed into a metal in the laboratory. So say a pair of scientists in Germany, whose bold claim is being met with skepticism.

Many scientists have tried to make metallic hydrogen since its existence was first predicted in 1935. The exotic substance is thought to form at high pressures, such as those in Jupiter’s core.