Creating High-Energy-Density Conditions

Abstract

Nature often creates high-energy-density conditions. At root, the cause is always gravity. At the center of the Earth, for example, the pressure is 3.6 Mbars, almost entirely due to gravity. Jupiter is similar, with a pressure of ~40 Mbars at its core. In stars, the gravitational assembly of the stellar mass leads to heating by nuclear fusion, which produces much larger pressures – the pressure at the core of the Sun is roughly 0.2 terabars. Once fusion creates conditions that lead to supernova explosions, even larger pressures occur. For example, some supernovae produce neutron stars, and the magnetic field at the surface of a typical neutron star is near 1 teraGauss. The pressure of such a magnetic field is about 40 petabars.