When Einstein Walked with Gödel: Excursions to the Edge of Thought

by Jim Holt

In general, things that have been around for a long time will likely be around for a lot longer. Conversely, things of recent origin likely won’t be. Both of these conclusions flow from the “Copernican principle,” which says, in essence, you’re not special. If there’s nothing special about our perspective, we’re unlikely to be observing any given thing at the very beginning or the very end of its existence. Let’s say you go to see a Broadway play. No one can be sure exactly how long the play will run. It could be anything from a few nights to many years. But you do know that of all the people who will see it, 95 percent of them will be among neither the first 2.5 percent nor the last 2.5 percent to do so. Therefore, if you’re not “special”—that is, if you’re just a random member of the play’s total audience—you can be 95 percent sure that you don’t fall into either of these two tails. What this means is that if the play has already had n performances at the point in its run when you happen to see it, you can be 95 percent sure that it has no more than 39 × n performances to go and no fewer than n ÷ 39. (This is a matter of elementary arithmetic: the upper