So the idea is that Boltzmann brains would form in smaller fluctuations, while a larger fluctuation would be required to account for us. Since smaller fluctuations are more common, it’s more likely that a given brain is a Boltzmann one.
Your wording implicitly assumes you’re not a Boltzmann brain. If you are one, the “us” is an illusion and no larger fluctuation is necessary.
Your wording implicitly assumes you’re not a Boltzmann brain.
That’s because I’m not one, and I know this! Look, even in the Bostrom argument, the prevalence of Boltzmann brains is the basis for rejecting the Boltzmann model. The argument’s structure is: This model says that it is highly improbable that I am not a Boltzmann brain. I am in fact not a Boltzmann brain. Therefore, this model is disconfirmed.
People seem to be assuming that the problem raised by the possibility of Boltzmann brains is some kind of radical skepticism. But that’s not the problem. Maybe some philosophers care about that kind of skepticism, but I don’t think it’s worth worrying about. The problem is that if a cosmological model predicts that I am a Boltzmann brain, then that model is disconfirmed by the fact that I’m not. And some people claim that our current cosmological models do in fact predict that I am a Boltzmann brain. Everyone in this debate takes it as granted that I am not actually a Boltzmann brain. I’m surprised people here regard this as a controversial premise.
Your wording implicitly assumes you’re not a Boltzmann brain. If you are one, the “us” is an illusion and no larger fluctuation is necessary.
That’s because I’m not one, and I know this! Look, even in the Bostrom argument, the prevalence of Boltzmann brains is the basis for rejecting the Boltzmann model. The argument’s structure is: This model says that it is highly improbable that I am not a Boltzmann brain. I am in fact not a Boltzmann brain. Therefore, this model is disconfirmed.
People seem to be assuming that the problem raised by the possibility of Boltzmann brains is some kind of radical skepticism. But that’s not the problem. Maybe some philosophers care about that kind of skepticism, but I don’t think it’s worth worrying about. The problem is that if a cosmological model predicts that I am a Boltzmann brain, then that model is disconfirmed by the fact that I’m not. And some people claim that our current cosmological models do in fact predict that I am a Boltzmann brain. Everyone in this debate takes it as granted that I am not actually a Boltzmann brain. I’m surprised people here regard this as a controversial premise.
See my reply to you elsethread. I also agree with this reply.
Oh, okay.
Is there a good introduction to Boltzmann brains somewhere? I don’t seem to understand it very well.
This is a good introduction:
http://blogs.discovermagazine.com/cosmicvariance/2006/08/01/boltzmanns-anthropic-brain/