Talk politics.

Having read through Liu Cixin's 2nd book from his trilogy Remembrance of Earth's Past, The Dark Forest, I've come across this take on the Fermi paradox:

Dark forest hypothesis (wiki)

The dark forest hypothesis is the idea that many alien civilizations exist throughout the universe, but are both silent and paranoid. In this framing, it is presumed that any space-faring civilization would view any other intelligent life as an inevitable threat,[2] and thus destroy any nascent life that makes its presence known. As a result, the electromagnetic spectrum would be relatively silent, without evidence of any intelligent alien life, as in a "dark forest" filled with "armed hunter(s) stalking through the trees like a ghost".

There's also a nice Kurzgesagt video on the subject (their vids are always awesome):
Youtube link

You've certainly heard of the famous Fermi paradox: having in mind how highly probable it is that alien life exists in the universe (given the vastness of space and the fact new exoplanets keep popping up every day, many already found within habitable zones), the question naturally arises why nobody has got in touch with us yet? If there are so many other civilizations out there, possibly at far more advanced stages than we are because of how long the universe's history is, surely at least a handful would've sent out messages or probes by now and tried to establish a contact?

Possible explanations for this paradox tend to range from the optimistic to the downright frightening. For one, it could be that we simply haven't been looking long enough, nor emitting our own traceable signatures for aliens to find us yet. Or it could be that no aliens will ever make it to the point where they're able to make contact with other species, what with the proneness of everyone to simply destroy themselves in a myriad of horrific ways long before they get to the kind of tech required to do this.

Anyways, on one extreme edge of the creepy scale falls this guy's Dark Forest hypothesis. One of his characters argues that it's inherent to life to strive to survive at any cost, and there's just no way of knowing the intentions of other alien species. Some could be benevolent, some could be hostile but you can never be sure before you've got in contact. Even if the life out there isn't hostile, it'll still be expanding in a universe with limited resources, which of course increases the likelihood of conflict with others in a scramble for those resources.

Given these factors, the author suggests, all intelligent life is left with the safest course of action: wipe out any other lifeforms before they can do the same to you. It's scary but it sounds plausible.

In fact he says it outright: "The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful, because everywhere in the forest are stealthy hunters like him. If he finds other life — another hunter, an angel or a demon, a delicate infant or a tottering old man, a fairy or a demigod — there’s only one thing he can do: open fire and eliminate them".

And also: "In this forest, hell is other people. An eternal threat that any life that exposes its own existence will be swiftly wiped out. This is the picture of cosmic civilization. It’s the explanation for the Fermi Paradox."

Mind you, this doesn't mean that we haven't heard from other species because they've all been wiped out, he argues. It's just that if even one species out there acts like this, it makes sense for all others to keep quiet, and not advertise their existence to others because the risks are much higher than the payoff from establishing contact.

However there's one factor that the book expands on, that though wiping out others before they can do the same to you is the most rational course of action, aliens may not do it for practical reasons. Say you send out a fleet of destroyers to another star system. By the time it gets there, your fleet will remain at the same technological level you sent it, while the people you're attacking will have advanced by centuries or even millenia. So chances are you've wasted all that resource for nothing.

Turns out, the most beneficial course of action to most civilizations might be to simply sit out there like many other forms of benevolent lifeforms, all hiding themselves in the forest in fear.

Thoughts?