Remember how you felt when you heard that Pluto is no longer considered a planet? Shocked? Dismayed? I felt a little of that initially, for Pluto had been viewed as a planet for as long as I had been alive. Once I read a couple of articles about the reclassification by the International Astronomical Union, however, it made sense to me. Astrophysicists had learned much about Pluto since it had been identified in 1930. It is far smaller than originally thought, is not a gas giant as once believed, and does not even dominate its orbital field. I am okay with recognizing that it is not the same as the eight remaining planets. Many people have not been so understanding. Neil Degrasse Tyson, astrophysicist and director of the Hayden Planetarium in New York, explains the situation in his lighthearted but still serious book The Pluto Files: The Rise and Fall of America's Favorite Planet.
The Pluto Files is partly a memoir, as Tyson recounts his own involvement in the reclassification, and partly a microhistory of Pluto, which is now called a "dwarf planet," a term that many (even those who agree with the concept) think is an unsatisfactory label. The author includes some of his own photos, lots of cartoons, and copies of emails and letters that he received from people objecting to Pluto's "demotion." It is through these communications that Tyson shows how resistant people are to change. Some people claim that it is unfair to make them learn something new. They seem to be more concerned about how expensive it will be to correct textbooks than concerned for getting the science right. Aren't textbooks always being replaced anyway? Isn't science about finding truth and not about maintaining old beliefs?
Just looking at that last paragraph, I see I am getting worked up. Tyson makes readers care about his subject. Moreover, he still seems to care for the little rock at the edge of the solar system. The Pluto Files is a clever celebration of astrophysics written for non-scientists.
Tyson, Neil Degrasse. The Pluto Files: The Rise and Fall of America's Favorite Planet. W.W. Norton, 2009. ISBN 9780393065206