>>11109696Among physicists, the simulation hypothesis is not popular and that’s for a good reason – we know that it is difficult to find consistent explanations for our observations. After all, finding consistent explanations is what we get paid to do.
Proclaiming that “the programmer did it” doesn’t only not explain anything - it teleports us back to the age of mythology. The simulation hypothesis annoys me because it intrudes on the terrain of physicists. It’s a bold claim about the laws of nature that however doesn’t pay any attention to what we know about the laws of nature.
First, to get it out of the way, there’s a trivial way in which the simulation hypothesis is correct: You could just interpret the presently accepted theories to mean that our universe computes the laws of nature. Then it’s tautologically true that we live in a computer simulation. It’s also a meaningless statement.
A stricter way to speak of the computational universe is to make more precise what is meant by ‘computing.’ You could say, for example, that the universe is made of bits and an algorithm encodes an ordered time-series which is executed on these bits. Good - but already we’re deep in the realm of physics.
If you try to build the universe from classical bits, you won’t get quantum effects, so forget about this – it doesn’t work. This might be somebody’s universe, maybe, but not ours. You either have to overthrow quantum mechanics (good luck), or you have to use qubits. [Note added for clarity: You might be able to get quantum mechanics from a classical, nonlocal approach, but nobody knows how to get quantum field theory from that.]
Even from qubits, however, nobody’s been able to recover the presently accepted fundamental theories – general relativity and the standard model of particle physics. The best attempt to date is that by Xiao-Gang Wen and collaborators, but they are still far away from getting back general relativity.
