Introduction

The great revolutions in physics of the early years of the twentieth century have their exact counterparts in the birth of astrophysics and astrophysical cosmology – these astronomical disciplines scarcely existed before 1900.

The history of the interaction between astronomy and fundamental physics is long and distinguished. From the birth of modern science, astronomy has provided scientific information on scales and under physical conditions which cannot be obtained in laboratory or terrestrial experiments. There is no better example than the history of the discovery of Newton's law of gravity, which provides a model for the process by which astronomical discovery is absorbed into the infrastructure of physics. The technological and managerial genius of the great Danish astronomer Tycho Brahe (1546–1601) and his magnificent achievements in positional astronomy during the period 1575 to 1595 provided the data which led to the discovery of the three laws of planetary motion of Johannes Kepler (1571– 1630) during the first two decades of the seventeenth century. The technical skill of Galileo Galilei (1564–1642) in telescope construction resulted in his discovery in 1610 of the satellites of Jupiter, which were recognised as a scale-model for the Copernican System of the World. Finally, in an extraordinary burst of scientific creativity, Isaac Newton (1643–1727) used Kepler's laws to discover the inverse square law of gravity and synthesised the laws of mechanics and dynamics into his three laws of motion.