SSA rejection of anthropic shadow could be illustrated by the following thought experiment: imagine that there are two universes:
One has anthropic shadow, so from 100 planets 99 planets died in LHC catastrophe.
Another universe has no anthropic shadow, so from 100 planets all will survive.
In this situation anthropic shadow is completely compensated by SSA, as I am 100 times more likely to find my self in the second universe with no anthropic shadow.
However, it works only if proportion of the universes with anthropic shadow to universes without such shadow is 1 : 1. If anthropic-shadow-universes are significantly more numerous, I will still more likely to be in the universe with anthropic shadow.
A SSA counterargument would be similar to Doomsday argument: imagine the universe with strong anthropic shadow, in which the number of habitable planets quickly declining.
In that case I am more likely to find myself near the bottom of the pyramid of all observers (earlier in time), so before the anthropic shadow effect. However, this works only for contemporary anthropic shadow like LHC, but not for shadows which happened before most qualified observers was born (cold war, climate change).
In the cold war example in my post, consider changing the post cold war population to higher than the pre cold war population (e.g. 5 billion); the conclusion still goes through.
An interesting thing is that if we use “natural reference class”—that is I am selected only from observers who think about anthropics, when most of them have started thinking about anthropics in 1990s or later – that is, after Cold war has ended.
However, if nuclear war would happen during Cold war, it would target university centers, so there will be less anthropics-conscious people now. This, in my view, rebuilds “anthropic shadow”.
SSA rejection of anthropic shadow could be illustrated by the following thought experiment: imagine that there are two universes:
One has anthropic shadow, so from 100 planets 99 planets died in LHC catastrophe.
Another universe has no anthropic shadow, so from 100 planets all will survive.
In this situation anthropic shadow is completely compensated by SSA, as I am 100 times more likely to find my self in the second universe with no anthropic shadow.
However, it works only if proportion of the universes with anthropic shadow to universes without such shadow is 1 : 1. If anthropic-shadow-universes are significantly more numerous, I will still more likely to be in the universe with anthropic shadow.
How does SSA compensate? I thought SIA would do that sort of thing?
Yes, it is more like SIA
A SSA counterargument would be similar to Doomsday argument: imagine the universe with strong anthropic shadow, in which the number of habitable planets quickly declining.
In that case I am more likely to find myself near the bottom of the pyramid of all observers (earlier in time), so before the anthropic shadow effect. However, this works only for contemporary anthropic shadow like LHC, but not for shadows which happened before most qualified observers was born (cold war, climate change).
In the cold war example in my post, consider changing the post cold war population to higher than the pre cold war population (e.g. 5 billion); the conclusion still goes through.
An interesting thing is that if we use “natural reference class”—that is I am selected only from observers who think about anthropics, when most of them have started thinking about anthropics in 1990s or later – that is, after Cold war has ended.
However, if nuclear war would happen during Cold war, it would target university centers, so there will be less anthropics-conscious people now. This, in my view, rebuilds “anthropic shadow”.
Both universes in this example are real, so it is SSA applied to the whole metaverse