Huh. I've been stewing on Up And Atom's video on the Landauer limit: https://youtu.be/XY-mbr-aAZE . If you don't know, Landauer's result connects Shannon's information entropy to Boltzmann's thermodynamic entropy by describing the minimum waste heat required to erase one bit of information i.e. cut the state space in half.

And a while later, Google's creepy Android newsfeed algorithm recommended to me this article about some researchers who claim that absolute zero is reachable in finite time, using finite energy, if you take quantum physics into account, i.e. a violation of the Third Law: https://thedebrief.org/quantum-version-of-the-third-law-of-thermodynamics-says-absolute-zero-is-theoretically-possible/ .

However, this claim is more reasonable than it seems, because the feat is only possible if you can perform infinitely complex manipulations. Complexity is just a synonym for information, so this means that you have infinite knowledge of the quantum state of the system being cooled, which is something you can only know the exact history of all particles since the last time they were each individually at 0 K.

It occurred to me that, since Landauer's equation connects energy to information/entropy, it's entirely possible that energy and information are the same thing, in almost exactly the same way that energy and mass. The weird difference is the dependency on absolute temperature. Temperature is just kinetic energy per volume, basically, so this implies that the more bits you pack into a given quantum system of fixed volume, the more energy it costs to erase one bit i.e. cool the system. That feels like it ties in very directly with the Bekenstein bound / black hole entropy, and the relationship with temperature as an "energy density" feels analogous to gravitational potential energy, i.e. bits get more expensive to remove as they fall into the gravity well because they are attracted to each other.

And, getting *very* far out on a limb: since the heat death of the universe is the process over which the expanding universe cools to 0 K over infinite time, the heat death is actually the *start* of time, is it not? Someone else's time, if not ours. After all, zero temperature means zero information entropy per volume. So I wonder if we actually have a twin universe for which our Big Bang is their heat death and vice versa, and that's what the AdS/CFT and dS/dS stuff is about. Perhaps our gravity could be dual to their thermodynamics, and their gravity to our thermodynamics, via some duality compatible with our respective geometries. Hell, since attraction looks like repulsion when you reverse the flow of time, maybe the thermodynamic information content of their universe (attractive) is dual to dark energy (repulsive) in ours?

#physics #QuantumPhysics #QuantumGravity #entropy #InformationEntropy #ItFromBit

#SethLloyd - Is #Information the Foundation of #Reality ?

https://www.youtube.com/watch?v=a35bKt1nuBo&ab_channel=CloserToTruth

#Science #Physics #Philosophy #PhilosophyOfScience #PhilosophyOfPhysics #Computing #Computability #UniversalComputation #ItFromBit #BitFlipping #QM #QuantumMechanics #QuantumPhysics #QuantumComputing #QuantumComputer #QuantumComputers #Qubit #Qubits #CloserToTruth #RobertKuhn