I've noticed several casual mentions recently of the idea that spacefaring civilizations might die off for one reason or another. Since I've yet to se an even halfway-plausible explanation for how this could happen, I've decided to issue a challenge:
I hereby challenge anyone to come up with a disaster, natural or artificial, that could reasonably be expected to render an advanced spacefaring species completely extinct.
For purposes of clarification:
1) The target civilization is assumed to have self-sustaining colonies in several solar systems spread across a volume of at least a few dozen cubic light-years.
2) The target civilization is assumed to have advanced robotics, genetic engineering, non-sentient AI, and other such technologies. Just to give exterminators a sporting chance, we'll pretend that nanotechnology and sentient AI don't exist.
3) The target civilization is assumed to be at least as intelligent and diverse as modern-day humanity. So let's not see any proposals that rely on them all making exactly the same idiotic mistake at the same time.
4) A proposed extinction event must be consistent with current astronomical knowledge (i.e. either it would be invisible to us, or it is something we've seen).
Just post your proposal. I'll reply with a specific explanation of how the target civilization could survive and rebuild, without recourse to ultratechnology or contrived foolishness. If you stump me, I'll post a message saying so. If you don't think my survival plan would work we can make a thread out of the argument (and we'll let the list judge which side makes more sense).
Are there any takers?
Billy Brown, MCSE+I