Introduction

Abstract

Investigations at temperatures below room temperature have advanced our knowledge in many ways. Toward the beginning of the present century, physical chemists evolved their reference state for chemical equilibria and thermodynamic properties on the basis of such studies. Later, physicists realized that a clear manifestation of quantum effects was possible at low temperatures. In recent times, superconductors, rocket fuels, cryopumping and a multitude of other developments have lifted low-temperature studies out of academic cloisters and into the realm of technology.