A surprisingly trim and concise history on the period of time between Le Verrier’s discovery of Neptune and Einstein’s theory of general relativity. In that interim period, a planet named Vulcan was born, lived in the minds of many, and then faded into obscurity before finally being decisively put down by Einstein many years later.
Considering the heavy topics this book covers (Newton’s theories, the discovery of Neptune, Einstein’s work, etc.), you’ll get the feeling that author Thomas Levenson is moving through the subject at warp speed. Compared to “Chasing Venus,” a book by Andrea Wulf about the early efforts to measure the transit of Venus across the sun, the effort to identify a planet between Mercury and the sun seem almost benign in comparison to that other exhaustively detailed effort. And before we’ve even had more than a few moments to consider that observational evidence wasn’t coming in, we’re jumping ahead in history to Einstein and the coup de grace.
Despite all that, it’s a great pop sci book. The existence of hypothetical planets is a fascinating topic on its own (how many people have ever even heard of such a thing as a hypothetical planet, let alone one that orbited the sun closer than Mercury?) and it’s especially relevant given astronomer Mike Brown’s announcement that there is a true ninth planet out beyond Pluto. At the moment, the Ninth Planet exists only on paper and in equations, and this book is an object lesson on all that this means; for while Neptune was discovered via the power of math and logic, so too was Vulcan inferred. Which will the Ninth Planet be? I can’t wait to find out and that’s what makes this book a great read. It’s one thing to go back and look at an interesting bit of scientific history; it’s ever so much more thrilling when you realize that we’re living through our own period of intense astronomical discovery.