Ya B Zeldovich and equation of state problems for matter under extreme conditions

In the amazing range of Yakov Borisovich Zeldovich's research interests-from general problems of chemical physics, kinetics, combustion, detonation, and shock waves to elementary particles and cosmology-the physics of matter under extreme conditions occupies a special position. This paper reviews some of Ya B's work on shock waves and equations of state of matter. Among Ya B's basic ideas are the utilization of shock data to develop thermodynamically complete equations of state; the shock compression of porous matter, and the adiabatic expansion of shock-compressed materials. The widespread use and development of these ideas as tools for the present-day studies of extreme conditions are illustrated with examples.