THE UNIVERSE IN THE REARVIEW MIRROR

Goldberg (Physics/Drexel Univ.; A User's Guide to the Universe: Surviving the Perils of Black Holes, Time Paradoxes, and Quantum Uncertainty, 2010, etc.) delivers relentlessly cheerful but comprehensible explanations of a dozen profound features of the universe.

Great scientific discoveries are less often the result of a new idea or equation than when someone realizes that things that appear different are, in fact, the same. Discovering that different things are identical often involves finding symmetries and almost-but-not-quite symmetries, a concept central to Goldberg’s approach to questions that seem trivial, such as, “Why is there something rather than nothing?” The Big Bang certainly began with equal amounts of matter and antimatter which should have annihilated each other, producing nothing. Yet the universe is made up of matter, with antimatter a rare laboratory curiosity. It turns out subtle differences exist between the two, but despite this, scientists don’t know why matter came out on top, although Goldberg explains what might have happened. Readers may be startled to learn that “nothing” can’t exist because it violates quantum laws. Empty space teems with particles that appear and vanish almost instantly. Not only does physics permit this, but experiments detect it. Everyone assumes that time only moves forward, but physical laws don’t require it, and all work fine if time runs backward, although this would produce paradoxes, which the author is happy to recount.

Goldberg belongs to the science-is-boring school of popularizers, so he peppers his text with jokes, apologies, digressions and cutesy asides (“In which I set everything up, so it’s probably best not to skip ahead”), but tolerant readers will learn a great deal about the current state of physics and cosmology.