Gravity: From Falling Apples to Supermassive Black Holes

Abstract

Abstract Sensational developments in gravitational physics have occurred in recent years. Gravity: From Falling Apples to Supermassive Black Holes offers an engaging, accessible, and up-to-date account of this subject. It explains some of the key ideas in astronomy and physics in a historical style, with stories about past and present researchers, leading up to the cutting-edge research of today. The historical narrative runs from the early cosmologies, through the great breakthroughs of Tycho and Kepler, to Galileo’s contributions to astronomy and mechanics, then considers the significance of Jeremiah Horrocks’s ideas. Newton’s theories of mechanics and gravity are presented in detail. Newton’s theories were superseded by Einstein’s general relativity, where gravity is explained as the curvature of four-dimensional spacetime by massive bodies. The text explains how Einstein used non-Euclidean geometry to construct his theory. It also considers the many ways in which general relativity has been tested. One of its predictions is the existence of black holes. The work of Penrose and Hawking is described, including more speculative ideas such as Hawking radiation, primordial black holes, and the search for a quantum theory of gravity. The book describes the recent discovery of gravitational waves and what they tell us about neutron stars and black holes. A supermassive black hole resides at the centre of all galaxies. One has been imaged by the Event Horizon Telescope. General relativity is also the basis for modern cosmology. The book describes the Big Bang, the cosmic microwave background, dark matter, dark energy, and cosmological inflation.