Soviet and US groups seek hydrogen's metallic phase

A group of Russian experimenters has recently reported (ZhETF Pis. Red. 5, 286, 1972) that they may have produced metallic hydrogen at a pressure of 2.8 megabars; at the transition the density changed from 1.08 to $1.3 g/cm3.$ Last year a Livermore group reported on an apparently similar experiment in which they observed a pressure—volume point centered at 2 megabars and $1 cm3/g.$ Some people have predicted that metallic hydrogen might be metastable, and others that it would be a room‐temperature superconductor.