For anyone interested in the (just for fun) topic of technological advancement, weaponry, and encounters with other civilizations, you should check out Vernor Vinge's Zone of Thought novels, a Fire Upon the Deep and A Deepness in the Sky. I can't recommend them enough.
In particular, he assumes that all civilizations will follow roughly the same arc of technological discovery, and that once they hit their information age, it's all about computational power and software. Which, of course, expand in power exponentially with time.
As for us explicitly preparing for that kind of encounter, sorry but if we run into hostiles we're screwed. Take any tech of your choosing and extrapolate. For example, a civilization a few hundred years more advanced than us could easily hit Earth with a custom-made virus or nanobots and wipe out humanity in a day. And if they were a few hundred thousand years more advanced? Impossible to say, but I think our only hope is think that we're too low-level for them to bother messing with.
Was AI accounted for at all? If super-intelligence can be achieved then technological advancement becomes more or less an issue of logistics, not time.
Yes, in fact AI of super-human intelligence plays a central role. To go into much detail would spoil one of the books, but needless to say Vinge supposes that exponential improvements in computing power will inevitably lead to that happening, and he does as good a job as I've seen anywhere in exploring the ramifications.
In particular, he assumes that all civilizations will follow roughly the same arc of technological discovery, and that once they hit their information age, it's all about computational power and software. Which, of course, expand in power exponentially with time.
As for us explicitly preparing for that kind of encounter, sorry but if we run into hostiles we're screwed. Take any tech of your choosing and extrapolate. For example, a civilization a few hundred years more advanced than us could easily hit Earth with a custom-made virus or nanobots and wipe out humanity in a day. And if they were a few hundred thousand years more advanced? Impossible to say, but I think our only hope is think that we're too low-level for them to bother messing with.