Then much later-about four or five years ago-I was on a long flight across the Pacific, staring idly out the window at moonlit ocean, when it occurred to me with a certain uncomfortable forcefulness that I didn’t know the first thing about the only planet I was ever going to live on. I had no idea, for example, why the oceans were salty but the Great Lakes weren’t. Didn’t have the faintest idea. I didn’t know if the oceans were growing more salty with time or less, and whether ocean salinity levels was something I should be concerned about or not. (I am very pleased to tell you that until the late 1970s scientists didn’t know the answers to these questions either. They just didn’t talk about it very audibly.)
And ocean salinity of course represented only the merest sliver of my ignorance. I didn’t know what a proton was, or a protein, didn’t know a quark from a quasar, didn’t understand how geologists could look at a layer of rock on a canyon wall and tell you how old it was, didn’t know anything really. I became gripped by a quiet, unwonted urge to know a little about these matters and to understand how people figured them out. That to me remained the greatest of all amazements-how scientists work things out. How does anybody know how much the Earth weighs or how old its rocks are or what really is way down there in the center? How can they know how and when the universe started and what it was like when it did? How do they know what goes on inside an atom? And how, come to that-or perhaps above all-can scientists so often seem to know nearly everything but then still can’t predict an earthquake or even tell us whether we should take an umbrella with us to the races next Wednesday?
So I decided that I would devote a portion of my life-three years, as it now turns out-to reading books and journals and finding saintly, patient experts prepared to answer a lot of outstandingly dumb questions. The idea was to see if it isn’t possible to understand and appreciate-marvel at, enjoy even-the wonder and accomplishments of science at a level that isn’t too technical or demanding, but isn’t entirely superficial either.