Metallic hydrogen, Liquid metallic hydrogen

Metallic hydrogen is a kind of degenerate matter, a phase of hydrogen in which it behaves like an electrical conductor. This phase was predicted in 1935 on theoretical grounds by Eugene Wigner and Hillard Bell Huntingto

At high pressure and temperatures, metallic hydrogen might exist as a liquid rather than a solid, and researchers think it is present in large quantities in the hot and gravitationally compressed interiors of Jupiter, Saturn, and in some extrasolar planets

In October 2016, there were claims that metallic hydrogen had been observed in the laboratory at a pressure of around 495 gigapascals (4,950,000 bar; 4,890,000 atm; 71,800,000 psi) In January 2017, scientists at Harvard University reported the first creation of metallic hydrogen in a laboratory, using a diamond anvil cell. Several researchers in the field doubt this claim. Some observations consistent with metallic behavior had been reported earlier, such as the observation of new phases of solid hydrogen under static conditions and, in dense liquid deuterium, electrical insulator-to-conductor transitions associated with an increase in optical reflectivity.
On October 5, 2016, Ranga Dias and Isaac F. Silvera of Harvard University released claims of experimental evidence that solid metallic hydrogen had been synthesised in the laboratory. This manuscript was available in October 2016, and a revised version was subsequently published in the journal Science in January 2017.