Why Haven't We Found Aliens Yet?

VOICE OVER: Ashley Bowman WRITTEN BY: Craig Butler
Written by Craig Butler

The search for alien life seems like it could go on forever. So, with billions of stars, planets and potential alien homes to choose from, why hasn't extra-terrestrial life made itself known? The Fermi Paradox goes some way to explaining the absence of aliens, but there are other theories too!

Why Haven’t We Found Aliens Yet?

Superman came to Earth in 1938. “The Thing from Another World” terrorized the Arctic in 1951. And E.T. has been phoning home since 1982. Aliens have been invading our planet’s pop culture for decades, but in the real world – nothing. We don’t see them walking down the street. They haven’t knocked on the door of the International Space Station. They don’t even have the common courtesy to answer the messages we beam out to them. So, exactly why haven’t we found any aliens yet?

It’s something that physicist Enrico Fermi wondered about, back in 1950. Referring to extraterrestrial life, he famously asked “Where is everybody?” thereby planting the seeds for what became known as the Fermi-Hart paradox - with Hart being another noted physicist at the time. Basically, the paradox states that with all the billions of stars and planets in our own galaxy, the odds are that there should be a large number of planets capable of developing intelligent life. Considering that many of those planets are older than Earth, some should have developed interstellar travel and should therefore have made it to our corner of the galaxy by now. But there’s been no evidence of this having happened… So, why not?

Fermi’s ideas seem even more reasonable when you look at the actual numbers. There are somewhere between 100 billion and 400 billion stars in the Milky Way alone. And the Milky Way is just one of some two trillion galaxies observable to us. So, if only 0.1% of the planets in our own galaxy that were potentially capable of harboring life actually had life, then there’d be around a million planets with some form of life on them now, in the past or in the future.

And it’s not like we haven’t made an effort to reach out. Since 1962, the Earth has been sending radio signals out into space, hoping that someone (or something) will eventually hear them and trace the signal back to us. A century before that, scientists were coming up with various light reflecting devices to try to catch the attention of potential alien fly-bys. Also, while we’ve only been sending out purposeful signals for a few decades, we’ve been listening for radio signals from space neighbors since the early 20th century. But still, silence.

One possible reason why is that we’re actually more advanced than everyone else. While we’re flitting to and from our space station, other life forms may only just be learning about flight, or they may have only just worked out the existence of other planets. Our radio signals could be reaching them, but they have no way of accessing them or understanding them, let alone replying to them. And if that’s the case, we definitely can’t expect them to just hop onto their interstellar hoverboards and pay us an actual visit.

Similarly, another popular theory argues that other life forms simply took too long to do just that; form. Known as the Gaian bottleneck theory, it essentially suggests that life on other habitable planets has developed too slowly. While there may have been (or may still be) planets with microbial life, it never evolves into a higher, more complex form. And by the time it is ready to evolve, whatever planet it populates has become too unstable to host it. So, under this model, Earth is very much the exception rather than the rule.

Then again, maybe we’re the underdeveloped ones. Maybe some physicist in a galaxy far, far away is wondering why nobody’s responding to his steady stream of neutrino communications – which we’d happily do, if only we had some way of noticing them in the first place.

Or ever consider this? What if the aliens don’t WANT to get in touch with us? Maybe these transcendent beings are so far above and beyond us that they reckon it would be a waste of time socializing (or even associating) with silly little carbon-based life forms like ourselves. But it might not just be a “they’re too good for us” thing. Maybe they’ve already had a good look around the Earth from a distance, and they’ve seen the way humans treat it, the way we treat other species, and the way we treat each other. And they’ve decided to steer well clear, for everyone’s sake.

Next, some people fall behind a theory known as the Great Filter, proposed by Robin Hanson in 1998. Hanson’s ideas go something like this: He says that The Fermi-Hart paradox makes a good case, that there should be a whole load of intelligent life out there, and that some of it should be more advanced than our own. But then the Great Filter comes into play, as Hanson theorizes some sort of cataclysmic event – possibly self-imposed – that befalls every civilization whenever it gets advanced enough to start moving out into other worlds. Of course, if that’s the case, have we already avoided the Great Filter because we’ve already made our first tentative steps space-wards? Or are we actually inching ever closer to our own appointment with a not-so-manifest destiny? Did someone say ‘Climate Change’?

Of course, there’s another really persuasive possibility to consider: That space is just too damn big and dangerous. Sure, the supporting statistics for Fermi, Hart and other like-minded scientists suggest that other life forms should exist out there. But even the nearest “out there” is a long, long way away from us. If the closest forms of intelligent life are just hundreds of light years away, that’s still too far for any terrestrial-type anything to travel. Even if a form of transportation was built that could withstand the rigors of traveling for hundreds of light years, and even if it could in fact move at the speed of light, it would still take generations to get to where it wanted to go. Sure, it’d be easier for some other form of communication to travel all that distance – but it would still take an unfathomably long time. And by the time any prospective alien communication reaches us, who’d know whether the civilization that sent it even still existed? Because it’s not likely that it would.

Naturally, when searching for life in space, we look mostly at stars that are most like our own. But, in fact, there are lots of much smaller stars – called low mass stars – out there. And not only are there more of them, but their lifespans are about 1,000 times longer than our sun’s – which should seemingly increase our chances of finding life there. The problem is, we don’t know if low mass stars can actually support life at all. And, in any case, the experts reckon that if life is going to evolve around one of these stars, it will do so in the far distant future. So, there’s that.

And there’s also this: Could it be that some alien species have opted to avoid us, because the weather isn’t to their liking? Some European researchers think that’s a genuine possibility, suggesting that some life forms may have decided that the universe was too hot for them to make the best use of their resources – so they’re sleeping for a few million years until things cool down a bit. The technical term is ‘aestivating’, and the strategy seems suspect until you consider that these life forms may have ditched their traditional, biological forms long ago. Instead, they’ve digitalized themselves as part of a super-futuristic, intergalactic way of life – ready for an ultra-efficient future existence. Us humans are simply nowhere near the level required to compete or even converse with that!

Finally, the notion that some life forms may have already evolved into a digital version of themselves brings up another possibility: That maybe we have in fact encountered aliens already but haven’t been equipped to recognize them. If we were to come across a being made of indescribable vapors, or dark matter, or some other form that we couldn’t even experience visually, would we know anything about it? Probably not, no. And on that basis, perhaps all of the classic science fiction stories and films were right, after all. Maybe aliens have found a way to live undetected among us and have already been here for years, looking and acting just like us.

And so, the question isn’t ‘Why Haven’t we found them yet?’, but more ‘Why haven’t we identified them yet?’. And why did they show up here in the first place??