Never On Sunday

Consider the following speculation on earth science. (In this context, “superficial” means literally “on the surface,” and not “trivial or frivolous” as we use it today.)

“Such changes in the superficial parts of the globe seemed to me unlikely to happen if the Earth were solid to the centre. I therefore imagined that the internal parts might be a fluid more dense, and of greater specific gravity than any of the solids we are acquainted with; which therefore might swim in or upon that fluid. Thus the surface of the globe would be a shell, capable of being broken and disordered by the violent movements of the fluid on which it rested.”

This quotation is remarkable not for its concise description of plate tectonics, but for its date; it is taken from a letter to Abbe Soulavie in 1782—the author, Benjamin Franklin. He is given no credit for the discovery because it wasn’t a discovery. There is no proof or even test of the idea, nor could there be at the time; it is simply the idle speculation of a remarkably intelligent person informed by such science as was available at the time. Nevertheless, the insight Franklin demonstrates is remarkable, and reminds us of the importance of good guessing in science.

Scientists begin with a hypothesis—literally, an educated guess. The most successful scientists are generally those who guess right, and therefore have the best chance to demonstrate their ideas before rivals who pursue blind pathways. Separating genius from luck in retrospect is difficult, to say the least.

But as important as clever guesses to scientific progress, and to scientific careers, it is important to remember that scientific authority has nothing to do with the guessing. Scientific authority comes from the rigorous testing and retesting and adversarial peer review that follows, and not from the plausibility of the guess, or the reputation of the guesser. That’s why creationism has no standing in the scientific world: it doesn’t stand up to rigorous testing, or even admit to a test at all. It’s not, as religious apologists often whine when they fail to clear that bar, because scientists are prejudiced. Scientists are, in a sense, close-minded: they are professionally required to be skeptical towards every idea that comes across their metaphorical desks…because that special breed of close-mindedness is the only way to separate ideas that might be true from those that definitely aren’t.

Franklin would cheerfully admit his idea had no scientific weight, but merely a certain plausibility, until and unless someone managed to prove it. If it’s good enough for the founding fathers, it should be good enough for would-be scientists who rely on appeals to authority over experimental evidence.