Why we might be alone in the universe

Statistics don’t care about your feelings

Earthrise (Credit: Nasa / public domain)

Few things are more dangerous than a single data point.

Imagine, if you will, that a million people are thrown in a jail, one inmate per cell. None know how many others are locked up with them, and each is given 60 seconds and a paper clip to pick the lock. If they succeed, they are free to go. If they fail, they die¹.

The timer starts and each occupant frantically begins trying to get out, but they have no idea how difficult the lock is. It turns out that the lock can be picked, but it takes, on average, several hundred hours of random prodding before it clicks open. Consequently, when the minute is up, all the inmates are dead. Well, all but one. For ease, let’s call him ‘Jack’.

Now, imagine walking up to Jack and asking him if it was hard. And he nonchalantly replies, “Oh, it was pretty easy. I just put the paper clip in the lock and it opened immediately.” Jack only has one data point to work with — his personal experience. And so from his perspective, it was no trouble at all to pick the lock. But if Jack were to learn of the 999,999 dead inmates left behind, he would likely reevaluate his position.

Now, imagine that each prison cell is in fact a planet, and each prisoner a sort of chemical soup trying to become alive in the limited time available while the planet is habitable. In which case we — Earth — are all Jack.

Statistics don’t care about your feelings

The above thought experiment is from David Kipping, a British astronomer and associate professor at Columbia University, best known for his pioneering research into exoplanets (and for wearing alarmingly tight-fitting t-shirts on camera).