Here is a brief recap of Peter Brannen’s recent piece in the Atlantic: “Why Earth’s History Appears So Miraculous: The strange, cosmic reason our evolutionary path will look ever luckier the longer we survive.”
Brannen begins by introducing us to the observer selection effect. (An observation selection effect exists when some property of a thing is correlated with the observer existing in the first place. For example, if intelligence hadn’t evolved, we wouldn’t exist, and couldn’t evaluate the probability of intelligence evolving.) The question Brannen asks is whether this bias applies to our planet.
If you consider all the existential threats our planets faced: “It’s something of a miracle that life on our planet has been left to evolve without fatal interruption for billions of years.” Of course, if we had been wiped out we wouldn’t be here to contemplate our existence. Thus, as a result of the selection effect, we probably underestimate the observed frequencies of cataclysmic events. And this means that “our forecasts about the future could be blinded by our necessarily lucky past.”
As Anders Sandberg, a senior research fellow at Oxford’s Future of Humanity Institute says:
Maybe the universe is super dangerous and Earth-like planets are destroyed at a very high rate, but if the universe is big enough, then when observers do show up on some very, very rare planets, they’ll look at the record of meteor impacts and disasters and say, ‘The universe looks pretty safe!’ But the problem is, of course, that their existence depends on them being very, very lucky. They’re actually living in an unsafe universe and next Tuesday they might get a very nasty surprise.
Perhaps this explains the Fermi paradox too. The reason we find no evidence of alien life is because there are no (or few) aliens and we exist only due to unimaginable good luck.
… suppose the many-worlds interpretation of quantum mechanics is right … So, one of the two versions of us ceases to exist, but do we actually notice that? So one of us keeps going on just as if nothing happened. Arguably, from moment to moment, I can’t rule out that five minutes ago the other version of us died. There’s no way for me to say that. So there’s an interesting, troubling question as to whether these things could be happening all the time and we just don’t even notice it.
The mind boggles at such suggestions.