Boiling Primordial Matter: 1968

Abstract

This introductory article presents in popular language how the view of the early Universe was evolving through 1968 under the influence of than new and recent insights about the thermodynamic properties of strongly interacting matter (by JR, editor). 16.1 The Large and the Small in the Universe Even though no one was present when the Universe was born, our current understanding of atomic, nuclear and elementary particle physics, constrained by the assumption that the Laws of Nature are unchanging, allows us to construct models with ever better and more accurate descriptions of the beginning. We begin to understand the composition and abundance distribution of nuclei, and we understand the origin of the energy which drives the Sun and countless other stars. We would have never understood these things if we had not advanced on Earth the fields of atomic and nuclear physics. To understand the great, we must descend into the very small. The objects, which will be discussed here, are incomprehensibly different in their size. In our daily lives a centimeter-sized object is a visible and reasonable magnitude; our direct experience ranges from "very thin"-a sheet of cellophane (10 3 cm)-to one hundred meters (10 4 cm); below and above these limits we no longer experience lengths directly through our senses, but indirectly with the assistance of our intellect-for example we imagine 100 km as one hour on the freeway. Even