Eh, I feel like we're just talking past each other at this point. Just to clarify exactly what my position is:
We posit that it makes sense to have a "backup": A physically isolated, self-sufficient ecosystem in which human civilization might continue independently. We can decide to put this backup in a distant gravity well, and call it a "colony". Or, we could decide to put it somewhere very, very safe on Earth, and maybe call it a "bunker".
My stance is that bunkers are universally preferable to colonies, at least for the foreseeable future of human technology: the bunker survives the same extinction events that the colony survives, and the inhabitants of the bunker have a better shot at rebuilding afterwards.
Reading between the lines, you seem to be supposing some event which destroys the bunker by definition. That would certainly suck for humanity, but it's answered by my most recent post: If there are human-extinction events the (Earth+)bunker wouldn't survive, there are dramatically more such events the (Earth+)colony wouldn't survive. So existentially, on the balance of probabilities, you are better served by building bunkers rather than colonies.
Mind you, I'm not saying there's no point in a colony; at some point, if you already have a dozen or a hundred bunkers, the marginal utility justifies the expense. And of course there are lots of reasons, both practical and sentimental, why we might want to go to Mars. It's just x-risk ain't a very good one.
We posit that it makes sense to have a "backup": A physically isolated, self-sufficient ecosystem in which human civilization might continue independently. We can decide to put this backup in a distant gravity well, and call it a "colony". Or, we could decide to put it somewhere very, very safe on Earth, and maybe call it a "bunker".
My stance is that bunkers are universally preferable to colonies, at least for the foreseeable future of human technology: the bunker survives the same extinction events that the colony survives, and the inhabitants of the bunker have a better shot at rebuilding afterwards.
Reading between the lines, you seem to be supposing some event which destroys the bunker by definition. That would certainly suck for humanity, but it's answered by my most recent post: If there are human-extinction events the (Earth+)bunker wouldn't survive, there are dramatically more such events the (Earth+)colony wouldn't survive. So existentially, on the balance of probabilities, you are better served by building bunkers rather than colonies.
Mind you, I'm not saying there's no point in a colony; at some point, if you already have a dozen or a hundred bunkers, the marginal utility justifies the expense. And of course there are lots of reasons, both practical and sentimental, why we might want to go to Mars. It's just x-risk ain't a very good one.