Swammerdami
Squadron Leader
The possibility of future technologies is not evidence that we in the putative present live in a simulation,
He is not claiming to have evidence, beyond feelings, intuition and common sense.
Feelings are not a basis for calculating probabilities.
To the contrary: "Feelings" are about the ONLY way to begin to estimate probabilities for a question as difficult as this. (Note that I am not agreeing that 50% is a good estimate, just that a GUESS is all we can aspire to. What's your guess, pood? Zero?
Although it has NOTHING to do with excreationist's hypothesis, analogy with an hypothesis of Boltzmann brain(s) is VERY USEFUL in understanding this probability estimation. With certain "logical" assumptions, the Boltzmann brain hypothesis is true with probability 99.99%+, but most would round this down to 50% (or better yet 0.0001%) to account for uncertainty about the "logical" assumptions.
I think excreationist is doing exactly the same. He has an argument that simulation is VERY likely, but, due to HUGE uncertainties in the modeling tempers that 99% down to about 50%.
IIUC it was Ludwig Boltzmann himself who first conceived of the Boltzmann brain hypothesis, but he didn't apply that name. Arthur Eddington and Richard Feynman are physicists who have pursued the hypothesis (but without considering it likely).
It is the (unexplained) Big Bang with its super-low entropy which renders Boltzmann brains extremely unlikely. I know of no such simple way to overturn excreationist's hypothesis.