In 1935 Eugene Wigner and his student Hillard Huntington predicted the existence of metallic hydrogen. Their calculations showed that, at high enough pressures, this dissociated form of hydrogen would conduct electricity. Three decades later the author predicted that, above a certain density, some monoatomic forms of metallic hydrogen would display high-temperature superconductivity. Yet 60 years after Wigner's original prediction, physicists are still waiting for conclusive proof that hydrogen can be made to conduct, never mind superconduct, electricity.