I have a few hobby horses on this blog (which because it is my blog, I’m allowed to have) and one of them is the quest for other intelligent life. You’ll find numerous articles where I’ve stated my conviction that this planet may be the only planet in the universe with intelligent life on it.
It seems an extraordinary thing to say given the fact that there are probably a trillion galaxies and each one with more than the 100 billion stars that our own Milky Way Galaxy possesses. So how could it be that this one small planet is the only one? Well, that would be because life is highly, highly, improbable. In fact the odds of there being life anywhere may well be a far bigger number than all those stars and galaxies.
If so, intelligence will evolve on just 1 in 100 trillion habitable worlds. If habitable worlds are rare, then we might be the only intelligent life in the galaxy, or even the visible Universe.
The article in question makes the argument from the basis of evolution, fair enough, but I found this chain of thoughts interesting. See what you think.
“Complex animals evolved once in life’s history, suggesting they’re improbable.”
“Surprisingly, many critical events in our evolutionary history are unique and, probably, improbable. One is the bony skeleton of vertebrates, which let large animals move onto land. The complex, eukaryotic cells that all animals and plants are built from, containing nuclei and mitochondria, evolved only once. Sex evolved just once. Photosynthesis, which increased the energy available to life and produced oxygen, is a one-off. For that matter, so is human-level intelligence.”
“These one-off innovations, critical flukes, may create a chain of evolutionary bottlenecks or filters. If so, our evolution wasn’t like winning the lottery. It was like winning the lottery again, and again, and again.”
“Intelligence seems to depend on a chain of improbable events. But given the vast number of planets, then like an infinite number of monkeys pounding on an infinite number of typewriters to write Hamlet, it’s bound to evolve somewhere. The improbable result was us.”
Except it’s not an infinite number of monkeys with an infinite number of typewriters with an infinite amount of time. None of those things are true. Time is very finite, even if there’s been a lot of it. The universe if limited, even if very, very vast. And life it seems is very, very rare even if on this planet there’s an awful lot of it.
So which is more likely, that we won the lottery again and again and again and again and again and again OR that there may be something else going on?