Engineering

The Clock in the Sun

Editorial: Columbia University Press

ISBN: 9780231202480

Pub: 2024-10-10

On the surface of the Sun, spots appear and fade in a predictable cycle, like a great clock in the sky. In medieval Russia, China, and Korea, monks and court astronomers recorded the appearance of these dark shapes, interpreting them as omens of things to come. In Western Europe, by contrast, where a cosmology originating with Aristotle prevailed, the Sun was regarded as part of the unchanging celestial realm, and it took observations through telescopes by Galileo and others to establish the reality of solar imperfections. In the nineteenth century, amateur astronomers discovered that sunspots ebb and flow about every eleven years—spurring speculation about their influence on the weather and even the stock market.