Computer scientists are in denial about it, but CS is a branch of theoretical physics, not mathematics. You can point to this or that model of computation, such as lambda calculus or mu-recursive functions and try to claim its abstracted well beyond the particular laws of physics for some specific universe, but they all have some kind of rate limit built into them... and where does the motivation for this idea, that it takes something (time, space, work) to compute something ultimately come from?
That's right - from underlying physics itself[1] - from the Bekenstein bound or Bremermann's limit or the like.
https://news.ycombinator.com/item?id=49699158
Quantum PKI all the way down - Dirac mechanics - and all the way up to gravity. Lloyd atomization rules
" . . From the universe's point of view, what we consider a super advanced computer is a lot closer to a space heater than anything that pushes up against its computational limits. Consider, for example, that quarks operate on time scales of 10^23 Hz, and the universe is happy to run three of those in every proton in every star in the universe. In fact, it runs 10^24 of them for one CPU, and that same CPU can't even simulate the quarks of one proton in real time.. . ."
