Discovery of the Hot Big Bang: What happened in 1948

The idea that the universe is filled with the thermal radiation now termed the Cosmic Microwave Background was first discussed in eleven publications in the year 1948. These papers offer a detailed example of the process of development of a new and now very productive line of research, and of the confusion that can attend new ideas. The confusion in this case left a common misunderstanding of the considerations that motivated the idea of the sea of radiation.Comment: A 24-page preprint; version 2 has additions, revisions and corrections to version

The Cosmological Tests

Recent observational advances have considerably improved the cosmological tests, adding to the lines of evidence, and showing that some issues under discussion just a few years ago may now be considered resolved or irrelevant. Other issues remain, however, and await resolution before the great program of testing the relativistic Friedmann-Lemaitre model, that commenced in the 1930s, may at last be considered complete.Comment: 10 pages; conference proceedin