Started yesterday between Tyler and myself by email, now over at Marginal Revolution.

To continue: if we are not in a simulation, then the question of “why the silence“?

Until recently, one idea was that the step from prokariyot (bacteria for example) to eukaryote (us and other complicated plants and animals) was the big filter, but the most recent evidence doesn’t support this notion.

I still think the filter idea might be operative, but at a much later point–when intelligent civilizations acquire the keys to thermonuclear reactions (aka, the bomb). Now we’ve been lucky for about 60 years, but that’s the blink of an eye in cosmological time. I’m not at all convinced that our luck will hold out.

It’s been said that a “Day After Tomorrow” full out nuclear exchange is no longer in the cards, but I recall seeing a Rand study (pdf), that indicated even a single nuclear blast in LA Harbor would be enough to bring down the US through follow on consequences across the economy and geopolitical sectors.

Note added in correction: A reader reminded me that the movie I’m referring to is The Day After…for which I am grateful.