An article in Nature reports that recent experiments may have confirmed the existence of a superionic phase of water, a concept that previously existed solely as a theory. Superionic material represents a strange state that is halfway between solid and liquid. In the case of water, for example, the oxygens under ultra-high pressure remain solid, but the hydrogens flow like liquid. The findings seem to confirm, in simulation, the existence of deep ice layers in Uranus and Neptune, which formed under ultra-high pressures and temperatures. The superionic state had been predicted theoretically in the late 1990s by a group of scientists that includes former ICTP acting director Erio Tosatti and ICTP staff scientist Sandro Scandolo. The lead author in the Science article that first presented this theory was Carlo Cavazzoni, a former student at the International School for Advanced Studies (SISSA).