Belknap Press / Viking · 2025
Ripples on the Cosmic Ocean reimagines the solar system as a mosaic of environments organized and entangled by the forces of electromagnetism and gravity. It argues that real and perceived changes in these environments shaped human history in previously untold ways.
The book shows that, beginning in the seventeenth century, cosmic environmental changes led astronomers and astronomy enthusiasts to believe that the solar system’s planets and moons were both inhabited and unstable. They responded by creating the principles and technologies for communicating between planets; designing novel machines and practices for observing the heavens; developing innovative literary genres; reinventing mass media; and even proposing the basic ideas underpinning what we now call the Anthropocene.
The book explains how cosmic environmental changes revealed the existence of forces, such as solar variability or asteroid impacts, that seemed capable of driving humanity to extinction. When the maturing union of science with government and industry in the twentieth century allowed states to imitate the effect of these destructive forces on Earth – by, for example, detonating nuclear bombs – the study of cosmic changes motivated efforts to mitigate so-called “existential” risks.
Ripples charts the twentieth-century emergence of a new era in which governments and large corporations managed emerging risks by monitoring and to some degree controlling the relationship between Earth and the broader environment of the solar system. In this new era, governments and corporations began to alter cosmic environments artificially – by importing terrestrial microorganisms to other worlds, for example, or creating swarms of radioactive particles in the space around Earth.
Ripples reveals that the final frontier is closer than we think. Today, environmental changes across the solar system not only influence human actions; they are increasingly caused by them. We now have a fleeting chance to consider how we might preserve Earth’s environment by reshaping the cosmic environments that surround it.
Want to learn more? Check out a six-part video series that introduces the sources, methods, and goals of Ripples on the Cosmic Ocean.
“A sweeping, stunning account of our place in the cosmos and its place in us.”Kirkus Reviews · starred review
“An unconventional, moving account of how Earth’s cosmic neighborhood shaped human existence…masterful.”Foreword Reviews · starred review
“Adroitly integrating science and history, Degroot effectively demonstrates that Earth is entangled in a dynamic ‘cosmic mosaic.’ This accessible and eloquent volume both entertains and educates.”Publishers Weekly
