In 1543, Polish astronomer and mathematician Copernicus published a then-radical theory, carefully timed just before his death: the Renaissance-era scientist had come to the conclusion that the Earth rotated around the sun. At the time, the implication that the Earth did not sit at the center of the universe was a deeply disturbing one. However, later on, this belief would prove extremely useful—for instance, when we began developing space-worthy crafts with which to explore the heavens.
Over four centuries later, a tourist touched a wall and wondered how long it would stand. The man in question was astrophysics professor J. Richard Gott, the wall was the Berlin Wall, and the professor was about to have a revelation, thanks in part to Copernicus.
Gott’s reasoning was this: in the same way that we are not the epicenter of the solar system, this moment and his presence were in no way integral to the history of the wall. This meant there was an equal chance he was standing there at the first quarter of its existence, the second quarter, the third quarter, or the final quarter. Since there was a 25% chance of inhabiting each quarter, there was a 50% chance of inhabiting the two middle quarters. According to this theory, it meant there was a 50% chance of the wall lasting between one-third or three times its age. The year was 1969; the wall had stood for eight years.
Plugging in the numbers, Gott found a 50% chance the wall would come down between about 1972 and 1993. When the Berlin Wall fell in 1989, it landed well within Gott’s range. An astrophysicist with no special knowledge of Germany, communism, or geopolitical situations had made a surprisingly sharp prediction, using only some simple math and a certain existential humility. Gott’s Principle (sometimes called the Copernican Principle) was born.
Now some caveats: if Gott had been invited the Berlin wall due to some sort of globally important political talk, the moment in time would not be random, and thus Gott’s probabilities wouldn’t apply.
Additionally, Gott’s Principle is only useful when it comes to predicting a timespan you don’t know. For instance, let’s say you’re sitting through minute sixty of a very boring movie. If you tried to use Gott’s Principle, you’d get a 50% chance the movie would continue for between twenty minutes and three hours. Given that the average movie these days is maybe 2 hours, unless you’re watching the collected Lord of the Rings trilogy, it’s highly unlikely that the movie would have a total runtime of four hours. It’s similarly irrelevant calculating human lifespans.
However, when you need a tool to track the cultural staying power of Bach, Brittany Spears, or the latest meme, Gott’s got your back.