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Jay Olson's avatar

No opportunity to arise in an empty galaxy at the present cosmic time, t=13.8Gyr. If the appearance rate of expansionistic civs is too high, every galaxy is already packed.

Self-indication says we should re-weight probabilities according to the relative number of observers who have anthropic information like ours (arising in an empty galaxy at t=13.8Gyr).

So, self-indication rules out super-low appearance rates (it wants more life), but also rules out super-high appearance rates (since that would imply dramatically fewer empty corners of the universe at the present cosmic time).

Thus, it squeezes our uncertainty about the appearance rate into a just few orders of magnitude.

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Jay Olson's avatar

I definitely see a net benefit from the POV of credibility.

As I see it, we have a subject that is one of the few remaining "really, really big questions" on the basic nature of the universe, but which has been avoided by a lot of science, due to the impossible-to-navigate proliferation of wild "what if" scenarios. That can create a massive, self-reinforcing problem for credibility.

But, then you get two independent lines of research that find a way to simplify the picture on a very large scale. They use different analytical methods, but the same basic postulates are returning a big set of nearly-identical conclusions.

That's got to be worth something.

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