Remember also that nukes may not be that effective against an interstellar civilizations and the technology that implies. Almost certainly useless against the point defenses a ship that travels at a fractional percentage of lightspeed would need for targeting and deflecting/destroying small space debris. On the Earth itself it should be suicidaly useful, but if the aliens feel we're a threat to them on the ground they can simply sterilize the planet from space.
Bottom line, if we're visited by a hostile alien race, it's likely to be game over - even with home field advantage.
Aliens would use pesticides and we'd never see them coming. See "The Screwfly Solution".
And it's a great point- but still, we have more chances with some sort of plan to defend ourselves than without.
Doesn’t that defeat the purpose?
But you're right- determining any degree of consensus for such a decision would be nearly impossible.
Then again- extinction event.
Uh.. Is that something one can 'recognise'? (It's a way of writing that begs the question.) Seems to me the threat of the first is not high, to say the least, but who knows. The threat of the second seems very high, well, at least if there are only 'a few nukes' on the planet. Otherwise nukes will get us first. I literally can't imagine 'nukes getting us first' but it does seem likely.
A digital superinteligence (should I expect it to be organic?) will be either very concentrated or backed-up everywhere. On the first case traditional explosives will give us better bang for our bucks, and lead to less collateral losses. On the second case, nuclear weapons would destroy us much sooner than the AI.
On the case of aliens, the entire problem is how to reach them. If we can get some weapon into them, yes, a nuke would probably be marginally more effective than a lump of lead, but not by a large difference.
"Attack and the planet gets it", see?
Of course we get it along with the planet, but I'm assuming that if the aliens are invading they're planning to exterminate us anyway.
I think yes. If you think about it, we have evidence that a technological civilisation can exist- ours. We don't have any evidence that a superintelligence can exist. So an alien civilisation invading us is a more credible threat than an emerging superintelligence turning us all into paper clips and whatnot.
What risk? What "alien invasion"? People understand about the speed of light and all right?
Alien civilizations might exist somewhere, but alien invasions are fairy tales for geeks.
That means that even for a species with a life span similar to that of humans, but possessing advanced enough technology to travel at half-light speed, it would not be impossible to launch an invasion from a point in space about 10 to 15 ish light years from here. If they started now, they'd be here in 30 years. The question of whether this is a realistic prospect comes down to how important it is to an intelligent species to have access to a planet that demonstrably can sustain life. My guess would be- really damn important. Important enough that we can be fairly sure that we ourselves will definitely look for that sort of planet in that sort of distance and time-frame, once we have achieved the technological capacity to do so.
And, like I say, the above is assuming a species with a life span similar to ours. Which is a big assumption. Maybe my hypothetical space invaders will have a typical lifespan of 1000 years, so that 50 years are nothing for them - a 20th of their lifetime. 5 of our years. Would we launch a 5-year space invasion to take control of a planet capable of harboring life? I bet we would. We'd send in the space marines alright (because an inhabited planet would present that sort of challenge to our control).
And who knows- if an alien civilisation is advanced enough to travel at half the speed of light, then maybe they also have the technology to artificially expand their life span. Maybe 1000 years is 20% of their life time. Maybe it's 1%. Maybe they don't really need to die anymore? So they can travel anywhere they like, at their own time. Of course in that case they can just wait around a few more centuries, until we've wiped ourselves out- problem solved. But maybe they have other reasons than their life span to hurry and take over a nice little blue gem like ours (theirs is all but exhausted, or a Tyranid Hive Fleet is approaching, that sort of thing).
What I'm saying is that the vastness of the distances across interstellar space may be a big problem for us but that doesn't necessarily mean that it's going to be as big a problem for a much more technologically advanced civilisation, also. And maybe we currently don't have the motivation to attempt such travel even if we had the means- but that, too, is not necessarily a quality shared with every other technological civilisation in our near galactic neighbourhood.
I think we should keep nuclear weapons around to lessen the risk of an alien invasion.
Assuming that a hostile alien species would suffer the same kind of damage as humans from high levels of radioactivity, possessing the power to turn the Earth into a ball of highly radioactive rock is a pretty damn good deterrent for what Iain M. Banks called an "out-of-context threat" (like the one the Conquistadores bestowed upon the ancient Mexicans, say- or like what we would risk faced with a technologically more advanced alien species).
So although I'm actually a pacifist and I am very worried about the prospect of nuclear holocaust (especially after hearing that nuclear weapons software runs on ... Windows XP... gulp) and although I do recognise that the threat of an invasion by an alien super-civilisation is at almost as remote as the threat from an emerging superintelligence, I still think we should totally keep a few nukes around, just in case.