Discordance: The Troubled History of the Hubble Constant [Hardcover]

The speed of the expansion of the universe is governed by the Hubble constant.Discordancetells of its troubled 100-year history, from tentative steps to measure the distances of nearby stars to orbiting telescopes peering into the far reaches of space. But recent results hint at more trouble ahead: the 'Hubble tension'. The story is not over yet.The troubled history of the Hubble constant told in an authoritative, comprehensible, and entertaining mannerIn 1927 Georges Lema?tre argued that our universe is expanding, a conclusion rendered more startling by the astronomical data that backed it up, presented two years later by Edwin Hubble. The speed of this expansion is governed by Hubble's constant, andDiscordancetells its troubled history.This unpredictable and fascinating story begins with the first tentative steps to measure the distances to nearby stars and galaxies. It traces the extraordinary interplay between cosmological theory and astronomical observation which has given us the standard Big Bang theory. It was not all plain sailing, and the narrative takes us through the discovery of dark matter, the Hubble Wars of the 1970s, the invention of cosmic inflation, and other crucial scientific moments. Further satellite missions were expected to add to the clarity of our measurements. But from about 2009 onward, the results began to diverge. This is the Hubble tension and perhaps even a crisis.Jim Baggott clearly and entertainingly guides the reader through this gripping scientific voyage--one littered with crises of confidence, astonishing discoveries, and extraordinary personalities--which still continues today.PrefacePrologue: Starry Messengers1. Miss Leavitt's Law2. The Scale of the Universe3. Hubble's Constant4. Divine Curves of Creation5. Parameters of the Universe6. Hubble Wars7. The Inflationary Universe8. Dark Energy and the Accelerating Universe9. Concordance10. The Hubble TensionEpilogue: DiscordanceAppendix 1: Symbols