It’s one of the greatest mysteries we face in modern science – where are the aliens? It’s a really intriguing question because, based on everything we know about life on Earth, sheer chance should have jump-started life on many other planets. Of the planets that do have life, some of them need to have developed intelligent life. And so we expect to see signs of that when we look to the heavens.
And for much of the 20th century up to today we have been looking pretty hard. Projects like SETI, or “Search for Extraterrestrial Intelligence”, have been scanning the galaxy for any sign that we aren’t alone. So far they’ve come up with a big fat zero, and no one really knows why.
In this article I want to go over some of the reasons that have been put forward to explain the lack of visible intelligent life, despite the billions and billions (and billions) of places where they may be. Just where are they, already?
Before we look at the reasons why we might not be seeing alien life, it’s worth talking about why we should care; especially from a transhumanist point of view.
First of all, if there are intelligent beings out there, they may have more pieces of the universal puzzle than we do. Learning about other intelligent creatures could boost our technology and expand our knowledge in other ways. That is, without us even coming into contact with them, which is highly unlikely in any event. Secondly, learning about the existence of extraterrestrial intelligence or finding out how common or uncommon it really is will help us understand our own future as a species better. Right now, it may be that our chances of survival are slim because intelligence tends not to survive in this universe.
There are more reasons of course, depending on who you ask, but these are the two main reasons that we care from a transhumanist point of view – at least in my opinion. So let’s get on to the reasons scientists think we’re not getting any return calls from ET.
Aliens? We Are Alone!
This is a valid explanation and no observable evidence contradicts it, but it’s also the one I find incredibly difficult to believe. With the sheer, mind-numbing number of stars in the galaxy, there’s seems to be little chance that this is true.
The thing is, we have no real way of estimating how rare life is and we don’t know all the factors that have lead to the jump-starting of life on Earth. It may be that some particular aspect of Earth’s configuration or nature is essential and also very rare – so rare that in the entire universe intelligent life has only sprung up infrequently, and perhaps lived long enough to be detectable even less frequently than that. This leads to the next reason.
They’re Dead, Jim
Humans have come close to wiping themselves out a few times, and in the future our technology may kill us off completely. For all we know that’s the inevitable fate of all or most intelligent species – advance for millennia, undergo a technological explosion, and then wipe yourself out. It’s depressing, but it could also be the true explanation.
Bostrom was Right
Elsewhere on this site you’ll find an article about what it could be like living as a sim, in case we ever go that way in the future. Well, if you listen to the arguments from philosopher Nick Bostrom, chances are that we’re already sims living in a simulation. If that’s the case, the intelligent beings who are simulating this universe may simply not have bothered to simulate other intelligences. It’s pretty far-out (man), but it could be true.
We’re Galactic Hillbillies
This is another simple, if unflattering, explanation. We may just have started life in a part of the Galaxy where no one else is. For all we know there may be an absolutely teaming interstellar community elsewhere in the galaxy, but here in Hicksville no one bothers to visit – other than to harass our livestock, apparently.
They Don’t Make Any Noise
Our main strategy so far has been to look for radio transmissions such as the ones we leak into space all the time, but there’s no real reason to think that this method of transmission is common to other intelligences. Even if other civilizations did use radio transmissions, they may stop very quickly on a cosmic time scale. After all, we only really used radio for a century or so and already we’re shifting to other methods of communication that don’t blare out into the universe.
They’re Just Too Weird
The only sort of life we know is the kind that evolved on Earth, and even the some life here is almost too weird for us to understand. Alien creatures who evolved independently in a completely different environment may be so strange to us that we couldn’t recognize them as life even if we tried. There may be communication going on that we simply can’t understand or even see.
They Already Came
This is one I heard from Neil DeGrasse Tyson, a popular TV astrophysicist. He says that one of the reasons we may not find aliens is because they’ve decided they don’t want us to find them. At least not yet. They came, they saw, they were interested, and they left. Maybe some are still here? Who knows, but good luck sleeping tonight.