British astronomer Watson (Why Is Uranus Upside Down? And Other Questions About the Universe, 2007, etc.) takes readers on a genial tour of the known—and imagined—universe.
“A typical place in the Universe is empty, cold and dark. And nothing in our experience can quantify just how empty, cold and dark it is.” So, with a nicely dramatic touch, writes the author, a pioneer in optics, long resident as a researcher in Australia, with an asteroid named in his honor. He has been on the astronomical scene for decades and is thus well positioned to track the development of theories on such matters as the nature of dark matter and, closer to home, the formation of the Earth’s moon. On the latter, he discards older notions that the moon was formed by accreted space debris and instead examines the “most popular contemporary theory,” namely that some large body, such as the “Mars-sized collider” called Theia, ran into Earth early in the planet’s history and threw a moon-sized section into orbit around the planet. The theory is not without its problems, but Watson is on the spot with research less than a year old that indicates that the moon is made mostly of “terrestrial magma, rather than rocky debris from Theia.” The evolution-of-ideas theme carries over to the famed Big Bang theory, which has been reverberating in one iteration or another for a century but has recently been complicated by the notion of “dark energy” and its role in the speed with which the universe expanded during those billions of explosive years. “The acceleration kicked in,” writes Watson, “only when galaxies were far enough apart for dark energy to begin to overcome gravity.” The author writes accessibly, and though some of the discussions may be a touch dense for readers without a background in astronomy, he doesn’t shy away from telling tales out of school, as when he reveals that one supposed signal from across the universe turned out to be a burst of radiation from a microwave oven in the lunchroom.
An up-to-the-minute, entertaining revelation for armchair explorers of deep space.