Thanks for the great writeup (and the video). I think I finally understand the gist of the argument now.
The argument seems to raise another interesting question about the grabby aliens part.
He’s using the hypothesis of grabby aliens to explain away the model’s low probability of us appearing early (and I presume we’re one of these grabby aliens). But this leads to a similar problem: Robin Hanson (or anyone reading this) has a very low probability of appearing this early amongst all the humans to ever exist.
This low probability would also require a similar hypothesis to explain away. The only way to explain that is some hypothesis where he’s not actually that early amongst the total humans to ever exist which means we turn out not to be “grabby”?
This seems like one the problems with anthropic reasoning arguments and I’m unsure how seriously to take them.
The only way to explain that is some hypothesis where he’s not actually that early amongst the total humans to ever exist which means we turn out not to be “grabby”.
You’ve rediscovered the doomsday argument! Fun fact: According to Wikipedia, this argument was first formally proposed by Brandon Carter, the author of the hard-steps model. He has also given name to the anthropic principle.
Edit: note that us not becoming grabby doesn’t contradict the model. There’s a chance that we will not. Plus, the model tells us that hearing alien messages or discovering alien ruins would be terrible news in that regard. I’ll explain the reason in the next part.
There may be a tradeoff, where by becoming simpler the civilization can spread across the universe faster. So the fastest spreading civilizations are non-sentient von-Neumann-probe maximizers.
That would explain why sentient beings find themselves early in the universe.
Thanks for the great writeup (and the video). I think I finally understand the gist of the argument now.
The argument seems to raise another interesting question about the grabby aliens part.
He’s using the hypothesis of grabby aliens to explain away the model’s low probability of us appearing early (and I presume we’re one of these grabby aliens). But this leads to a similar problem: Robin Hanson (or anyone reading this) has a very low probability of appearing this early amongst all the humans to ever exist.
This low probability would also require a similar hypothesis to explain away. The only way to explain that is some hypothesis where he’s not actually that early amongst the total humans to ever exist which means we turn out not to be “grabby”?
This seems like one the problems with anthropic reasoning arguments and I’m unsure how seriously to take them.
You’ve rediscovered the doomsday argument! Fun fact: According to Wikipedia, this argument was first formally proposed by Brandon Carter, the author of the hard-steps model. He has also given name to the anthropic principle.
Edit: note that us not becoming grabby doesn’t contradict the model. There’s a chance that we will not. Plus, the model tells us that hearing alien messages or discovering alien ruins would be terrible news in that regard. I’ll explain the reason in the next part.
We can also become grabby without being there anymore, e.g. the paperclip maximizer scenario.
There may be a tradeoff, where by becoming simpler the civilization can spread across the universe faster. So the fastest spreading civilizations are non-sentient von-Neumann-probe maximizers.
That would explain why sentient beings find themselves early in the universe.
Small world, I guess :) I knew I heard this type of argument before, but I couldn’t remember the name of it.
So it seems like the grabby aliens model contradicts the doomsday argument unless one of these is true:
We live in a “grabby” universe, but one with few or no sentient beings long-term?
The reference classes for the 2 arguments are somehow different (like discussed above)