In The Neptune File, Standage expertly balances personal drama and the intellectual excitement of a radical new idea. The new idea rests on the notion that the eccentricities of Uranus’s orbit can only be explained by the gravitational pull of another planet. What makes it so radical is that mathemeticians work out where the new planet could be — and try to convince astronomers to point there telescopes at that area of the sky. The drama arises from John Couch Adams (in England) and Urbain Jean-Joseph (in France) computing Neptune’s orbit at almost exactly the same time, with attendant nationalistic rivalry (there’s even the suggestion of a minor conspiracy with the intent of assuring the planet was first officially observed on the English side by a Cambridge-affiliated astronomer).
Standage with opens Herschel’s discovery of Uranus by way of background, pays some attention to the contention-fraught business of planet naming, discusses “Bode’s law” and the “missing” planet between Mars and Jupiter, and goes beyond Neptune to Pluto and other similar objects that were never called planets — and even beyond that to extrasolar planets, which take the radical idea to its ultimate conclusion: since planets around other stars are too distant to observe directly with an optical telescope, the only way to find them is through the pertuberances of orbits. (Strictly speaking, the planets of the solar system don’t actually orbit the sun; the sun and the planets orbit their mutual center of gravity. Since the sun is far more massive than the sum of the planets, this basically means the sun wobbles a little bit, and through similar wobbles the presence of planets around other stars can be detected.)
The previous two books of Standage’s that I read, The Victorian Internet and The Turk were so lively and well-written that I recommended them to pretty much anyone, not just those with an interest in history. The Neptune File perhaps has less sizzle. I wouldn’t push it on someone with no interest whatsoever in astronomy, or someone with no tolerance for history. But if the phrase “astronomical history” makes your eyes light up a little (instead of glaze over…) this is a definite must-read.
needs more demons? no.