Monday, March 22, 2010

Eating one's shorts

Back in 1970, the planetary scientist Larry Taylor promised his colleagues he'd "eat his shorts" if there was water on the Moon. He had good reason for saying so: a careful analysis of Moon rocks collected the previous year by Apollo 11 astronauts revealed pure unoxidized iron -- nothing that would indicate the presence of water.

At this year's Lunar and Planetary Science Conference he didn't eat his shorts, but he ate his words. A new analysis of Apollo rocks and recent data from India's Chandrayaan-1 and NASA's Lunar Reconnaissance Orbiter spacecraft indicate water in the body of the Moon after all -- which will require some readjustment of theories of the Moon's origin. Taylor's colleagues provided a cake iced with an image of boxer shorts.

This anecdote is not unusual; almost any issue of Science or Nature contains an example of a scientist or scientists "eating their shorts." Usually it's a small matter; sometimes it's paradigm shattering. Science has been so fabulously successful as a way of knowing precisely because nature is given the last word.

Larry Taylor's cake was especially refreshing to read about given the clashes of unbending opinion that have dominated the political and religious news lately. Nature is not only disallowed the last word; it is not even given the first word. All of which leads to a personal examination of conscience: To what extent are my own beliefs fixed in stone?

Inevitably, our religious and political views are predisposed by the circumstances of our birth and upbringing. People overwhelmingly adopt the religion of their parents and teachers. To a lesser extent this is true of politics too. Genes may even have something to do with whether we are liberal or conservative. And, to be sure, the more of our life we invest in a particular suite of "truths," the more reluctant we are to change.

When I was a young graduate student in physics at UCLA I had a friend, a secular Panamanian Jew, with whom I often ate my brown-bag lunch, sitting in the campus botanical garden. He had a habit of asking me "Why?" Why did I believe Catholicism was the "true faith"? Why did I believe in immortality? Why did I believe in the efficacy of prayer? Why did I believe in miracles? And so on. As he gently urged the point home, it became increasingly clear to me that I had not the slightest non-anecdotal evidence for my beliefs, and that in different cultural circumstances I might believe something entirely different. Since that time, I have tried to be respectful of where I have been, but determined not to make "leaps of faith" in the absence of empirical evidence. Better to say "I don't know" than to objectify the subjective.

The late Harvard psychologist John Mack, he of the alien abductions, once told an audience -- in response to a skeptical column of mine -- that if an alien spacecraft landed in Boston Common and all the major news outlets where there to record the event "Chet Raymo still wouldn't believe." He was certainly correct that my first response would be to suspect an elaborate hoax. But if the aliens took me on board, and then zipped me away to Mars at the speed of light -- well, I hope I would be honest enough to eat my shorts.