David Zuilhof

I am writing my physics bachelor thesis on the Boltzmann brain paradox. Boltzmann brains are brains that fluctuate into existence due to random quantum fluctuations in empty space, which have the exact same experience as you are having right now. The question arises: “How do you know that you are not a Boltzmann brain?” You cannot determine this based on your current experience or memories because a Boltzmann brain has the exact same experience and memories as you. To make matters worse, the odds are heavily stacked against you. This is because although it's very unlikely for a Boltzmann brain to fluctuate into existence in a random volume of empty space, it's WAY less likely for the entire universe such as we currently understand it to fluctuate into existence. Moreover, since Boltzmann brains can fluctuate into existence after the heat death of the universe, if our universe becomes infinitely old (or at least VERY old) it will contain way more Boltzmann brains that have your experience than that our universe will contain brains that have your current experience with a corresponding mind-independent reality, i.e. brains in which your current experience is not just a mere hallucination. My bachelor thesis is about investigating the assumptions in our best physical theories from which the Boltzmann brain paradox arises, about how old (and how big) exactly our universe needs to get for the Boltzmann brain paradox to arise and about potential solutions to the Boltzmann brain paradox.