The logic is that the universe of big bang matter has a limited lifespan. This sets a hard limit on the number of humans via “normal” means.
Boltzmann brains are due to a quirk of quantum mechanics. Matter can come into existence spontaneously. The rate is proportional to the amount (technically the energy content). Given enough time and space, something that would fit the definition of human could spontaneously appear. The odds of this are unbelievably long, but, so long as it’s finitely large, in a true infinite universe it will happen an infinite number of times. It’s a bit of infinity Vs very large number weirdness.
End result is that there will be a large but finite number of “normal” humans, but an infinite number of Boltzmann brain humans. Therefore, the chances of being an actual “normal” human is effectively infinitesimal.
Agreed about it not mattering, day to day. It’s one of those things that is of interest to theoretical physicists, since it might tell us something interesting about the nature of our universe.
The logic is that the universe of big bang matter has a limited lifespan. This sets a hard limit on the number of humans via “normal” means.
Boltzmann brains are due to a quirk of quantum mechanics. Matter can come into existence spontaneously. The rate is proportional to the amount (technically the energy content). Given enough time and space, something that would fit the definition of human could spontaneously appear. The odds of this are unbelievably long, but, so long as it’s finitely large, in a true infinite universe it will happen an infinite number of times. It’s a bit of infinity Vs very large number weirdness.
End result is that there will be a large but finite number of “normal” humans, but an infinite number of Boltzmann brain humans. Therefore, the chances of being an actual “normal” human is effectively infinitesimal.
Agreed about it not mattering, day to day. It’s one of those things that is of interest to theoretical physicists, since it might tell us something interesting about the nature of our universe.
it is very interesting, but it’s also one of those topics that makes anything else in the conversation not matter.
also do note that i said nothing about thinking sensory inputs are illusory, just that belief is not required for things to exist.