John Mather

A sweeping account of the century of experimentation that confirmed Einstein’s general theory of relativity, bringing to life the science and scientists at the origins of relativity, the development of radio telescopes, the discovery of black holes and quasars, and the still unresolved place of gravity in quantum theory. Albert Einstein did nothing of note on May 29, 1919, yet that is when he became immortal. On that day, astronomer Arthur Eddington and his team observed a solar eclipse and found something extraordinary: gravity bends light, just as Einstein predicted. The finding confirmed the theory of general relativity, fundamentally changing our understanding of space and time. A century later, another group of astronomers is performing a similar experiment on a much larger scale. The Event Horizon Telescope, a globe-spanning array of radio dishes, is examining space surrounding Sagittarius A*, the supermassive black hole at the center of the Milky Way. As Ron Cowen recounts, the foremost goal of the experiment is to determine whether Einstein was right on the details. Gravity lies at the heart of what we don’t know about quantum mechanics, but tantalizing possibilities for deeper insight are offered by black holes. By observing starlight wrapping around Sagittarius A*, the telescope will not only provide the first direct view of an event horizon―a black hole’s point of no return―but will also enable scientists to test Einstein’s theory under the most extreme conditions. Gravity’s Century shows how we got from the pivotal observations of the 1919 eclipse to the Event Horizon Telescope, and what is at stake today. Breaking down the physics in clear and approachable language, Cowen makes vivid how the quest to understand gravity is really the quest to comprehend the universe.

New York Times Bestseller An exploration of the age-old complicity between skywatchers and warfighters, from the best-selling author of Astrophysics for People in a Hurry. In this fascinating foray into the centuries-old relationship between science and military power, acclaimed astrophysicist Neil deGrasse Tyson and writer-researcher Avis Lang examine how the methods and tools of astrophysics have been enlisted in the service of war. "The overlap is strong, and the knowledge flows in both directions," say the authors, because astrophysicists and military planners care about many of the same things: multi-spectral detection, ranging, tracking, imaging, high ground, nuclear fusion, and access to space. Tyson and Lang call it a "curiously complicit" alliance. "The universe is both the ultimate frontier and the highest of high grounds," they write. "Shared by both space scientists and space warriors, it’s a laboratory for one and a battlefield for the other. The explorer wants to understand it; the soldier wants to dominate it. But without the right technology―which is more or less the same technology for both parties―nobody can get to it, operate in it, scrutinize it, dominate it, or use it to their advantage and someone else’s disadvantage." Spanning early celestial navigation to satellite-enabled warfare, Accessory to War is a richly researched and provocative examination of the intersection of science, technology, industry, and power that will introduce Tyson’s millions of fans to yet another dimension of how the universe has shaped our lives and our world.