Given how curious we are, I think being scared of aliens is odd. I would assume that a civilization capable of interstellar travel is fairly chill.
And a sufficiently advanced alien civilization could sterilise earth from the comfort of their home star system, so if advanced aliens wanted us dead, it would not be hard, we wouldn’t even see it coming.
A civilization capable of interstellar travel would be a lot more advanced then we are. If we but this in perspective, we as humans don't really care about other species that much. Imagine a species that is more advanced tham we are compared to chimps. Some people respect chimps, but we keep them in zoos and destroy their living spaces.
An interstellar civilization could see us even lower than that, just some primates living on a rock. They might not even think us intelligent, we only just have 'understood' quantum theory.
I think that is an overly bleak view. An interstellar civilization is likely on a similar evolutionary ladder spot as us and I would imagine that they would recognize this. I don't think that there is much difference between us and them in that scenario, except how far we have developed our idea space. Supposedly with the help of such a civilization we would be able to accomplish the same feats as them in a fairly short time. No monkey is going to engineer rockets, no matter how long you try to teach them.
Ye, the civilization might see us as potential rivals even and to be exterminated before we reach their level. It would be very naive to think that any interaction with a more advanced species is gonna be positive for us
There's a Sci Fi trilogy about that. All aliens are omnicidal.
The main rule is "don't ever get spotted by another civilization". If another nearby civilization wants to conquer you, you could stop them by threatening to broadcast both our and their locations more broadly, a kind of mutually assured distruction.
I think the scary part stems from looking at ourselves. We're well on our way "out there" but still kill each other in the cruellest ways. Our sadistic qualities only limited by our means to perpetrate them.
Hawkins shared his thoughts on this subject and, although less morbid, still quite scary.
They may have stupid politics like us and need us as a common enemy to unite their factions/be racist at. So even if theyre not naturally genocidal, they might choose to "for the greater good". Plus our sweet sweet natural resources/scrap.
The best estimates of how many intelligent civilizations there should be suggest that the galaxy should be teeming with them. If any of them evolved mere millions of years before we did, given our pace of technological improvement they should have figured out interstellar travel by now, and they should be broadcasting communication across the galaxy like we're doing. Yet we've detected nothing. Why?
A possible explanation is that an advanced civilization is exterminating all other civilizations, perhaps to avoid competition. It seems like a sensible approach to lie low until we can figure this out, just in case.
That is a solution, there are multiple other solutions all equally or more likely that don’t involve murderous aliens.
One just as out there would be a sort of galactic zoo - there is simply an agreement not to interact with intelligent life before they reach a certain step, say establish global unity or develop a certain tech.
It could be that we are in fact a statistical outlier or are simply wrong in our probability calculations.
It could be that intelligence develops but spacefaring is rare. It could be that intelligent life simply has a tendency to collapse before it gets there. It is certainly still possible for us and it is not like we are making super meaningful progress towards space colonisation.
It could be that there are not great viable interstellar travel options, almost every option we have thought of that makes sense time wise has big ifs attached to it assuming we have a good idea of physics. Of those probably relativistic travel is the most likely and even then it would take quite a decent chunk of time to span the galaxy, going to war on those timescales is basically non-sensical.
I expect that any civilisation capable of cooperating at scale to achieve meaningful interstellar travel would also be developed enough in ethics to most likely not pose a danger to us.
A civilisation capable of waging war like that is probably around a K2 civ and the idea that a single planet somehow threatens them is also silly. Even a fully K1 civ to them would be close to a stadium packed full on earth in terms of relative size.
Absolutely, there's lots of possibilities. But I don't think that negates the point that the most sensible approach to any unknown situation is to be cautious and lie low until you fully understand the situation.
Of course, flawed as we are, we're not doing that, as we aren't responding to other potential existential threats.