This is a simulation

Bekenstein limits, (quantum) information theory and physics, dreams in the minds of gods etc…

Scott Aaronson, Your yearly dose of is-the-universe-a-simulation:

[…] to whatever extent we believe the Bekenstein bound […] we believe that in quantum gravity, any bounded physical system (with a short-wavelength cutoff, yada yada) lives in a Hilbert space of a finite number of qubits, perhaps \(~10^69\) qubits per square meter of surface area. And as a corollary, if the cosmological constant is indeed constant (so that galaxies more than ~20 billion light years away are receding from us faster than light), then our entire observable universe can be described as a system of \(~10^122\) qubits. The qubits would in some sense be the fundamental reality, from which Lorentz-invariant spacetime and all the rest would need to be recovered as low-energy effective descriptions. […] this would mean that our observable universe could be simulated by a quantum computer—or even for that matter by a classical computer, to high precision, using a mere \(~2^{10^122}\) time steps.


Was the universe a hologram or a simulation? Was its boundary a program, or merely an interface? And if the latter, what sat on the other side watching it run? A few latter-day religions had predictably answered that question with the names of their favourite deities. Brüks had never been entirely clear on what an omniscient being would need a computer for. Computation, after all, implied a problem not yet solved; insights not yet achieved. There was really only one sort of program for which foreknowledge of the outcome didn’t diminish the point of the exercise. And Brüks had never been able to find any religious orders which described God as a porn addict.

— Peter Watts, Echopraxia.

  • Egan, G. (1997). Distress. Nightshade Book.
  • Watts, P. (2014). Echopraxia. [S.l.]: Tor.

Hsu, Stephen D. H. 2020. “Discrete Hilbert Space, the Born Rule, and Quantum Gravity,” July.