The Discovery of the Universe

Abstract

On the threshold of the twentieth century, many scientists believed that the most important discoveries in physics and astronomy had already been made. Gravitation had been shown to be able to describe any type of motion, from laboratory mechanics to stellar dynamics. On the structure of the Universe, the prevailing view was in favour of one ‘large galaxy’ rather than innumerable ‘island universes’, distributed in space. However, in the laboratory and observatories, one began to glimpse at titanic changes that would upset the physics, astrophysics and cosmology of the twentieth century. The experiments of 1887 by Albert Michelson (1852–1931) and Edward Morley (1838–1923) ruled out the presence of the mysterious ‘ether’ that was often invoked to explain anomalies in planetary motions, the absence of which constituted a matter of uncertainty. At the same time, Dalton’s solid theory of atom was gradually being undermined by new physical evidence: in 1897, Joseph J. Thomson (1856–1940) discovered the electron, and from 1908, Ernest Rutherford (1871–1937) began to describe the atom in modern terms of electrons and protons. Max Planck (1858–1947), correctly interpreting the spectrum of a blackbody, gave rise to the quantum theory and quantum mechanics, and the theory of relativity of Albert Einstein (1879–1955) was transforming the concepts of space and time that had been accepted for centuries.