Winner, 2025 Choice Outstanding Academic Title

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.

Exploring these and many other crucial developments, Pierre Sokolsky provides a history of knowledge of the Sun through the lens of sunspots and the solar cycle. He ranges widely across cultures and throughout history, from the earliest recorded observations of sunspots in Chinese annals to satellites orbiting the Sun today, and from worship of the Sun as a deity in ancient times to present-day scientific understandings of stars and their magnetic fields. Considering how various thinkers sought to solve the puzzle of sunspots, Sokolsky sheds new light on key discoveries and the people who made them, as well as their historical and cultural contexts. Fast-paced, comprehensive, and learned, The Clock in the Sun shows readers our closest star from many new angles.

"The Clock in the Sun catches the pulse of our favorite star as well as that of our intellectual history with it. Interested readers of all levels will have something to learn and enjoy." - Open Letters Review

"Offers fascinating reading. [The Clock in the Sun] brings readers up to date on the current solar model, while informing them of the rich history of solar astronomy." - Mark Lardas, Ricochet

"Provides a unique look at world history as seen through the lens of solar astronomy. Mr. Sokolsky does a splendid job." - The Wall Street Journal

"The Clock in the Sun is a fascinating account of humanity's relationship with the sun. Sokolsky weaves a compelling yarn that spans over 1,000 years of astronomical history, from humanity’s worship of the sun in ancient times to the constellation of spacecraft that monitor it 24/7 today. Rich in both history and science, this is an engaging, thought-provoking read. Highly recommended." - T.D. Oswalt, Choice Reviews

"Sokolsky provides a comprehensive history of the science of the sun from antiquity to the present. In the process, he offers portraits of the people responsible for these discoveries and illuminates the ways in which ideas travel and evolve between cultures and across time." - University of Chicago Magazine