The boltzman brain idea had me realize something important... in any infinite universe where life is possible, however unlikely, **must** have life in it.
Add in limitations on light speed and if that life is sufficiently rare than all instances of life would be unable to observe any other instance of life.
@icedquinn Not at all, fermis parodox relies on the vastness of the **observable** universe. It is such that no matter how conservative the values you put in, within what feels like reason, you will still get a high chance of life.
However in fermi's paradox you can reverse the equation and find the probabilities needed to ensure the equation shows no life, they just require a very very low ratio. But yea there is a threshold in fermi's paradox where "if life is less likely than this number then life likely wouldnt exis"
The key difference here is now we are thinking about the whole (non-observable) universe and working up. The idea that **any** probability garuntees life, and that from that life's perspective there would be an empty **observable** universe is very much a departure from fermis paradox.