RIPPLES IN SPACETIME

A fascinating story of astronomy that represents “the culmination of a century-long quest and the starting point for a completely new chapter in our exploration of the universe.”

The detection of gravitational waves in 2015 produced fewer headlines than the 2013 discovery of the Higgs particle, but it may be more significant; it’s also easier to explain. Of course, “easier to explain” is not the same as “easy,” but science journalist Schilling (Deep Space: Beyond the Solar System to the End of the Universe and the Beginning of Time, 2014, etc.) walks readers through a lucid history of the universe, of general relativity, and of the bumpy search for Einstein’s last major unconfirmed prediction: the existence of gravitational waves. The author reminds readers that scientists regarded gravity as a force between bodies (like electromagnetism) until Einstein set them straight. He showed that any object with mass distorts space-time in its vicinity; no force acts on nearby bodies, but their movement appears to curve as they pass through. He also theorized that an accelerating body loses energy in the form of gravity waves, which are extremely faint. Schilling delivers a lively, expert, mostly comprehensible account, equal parts politics, personality, and science, of the search that ended two years ago when “for about one-fifth of a second…sensitive detectors measured ripples in spacetime that were 10,000 times as small as the diameter of a proton.” Schilling emphasizes that this is not simply another feather in Einstein’s cap, but a valuable new tool. The early universe was opaque to radiation until 380,000 years after the Big Bang, but gravity waves poured out from almost the beginning, so a new field of “gravitational wave astronomy” can look back almost to the birth of the cosmos.

An exciting history of the second great breakthrough of 21st-century physics.