Let me clarify what I mean:
If you put 80W of electrical energy into an ideal electrical heater, it will put out 80W of heat energy.
But what if you put 80W of electrical energy into a CPU and let it calculate things, creating new information?
Will it also output exactly 80W of heat?
Or is some energy transformed into “information”, so the CPU will radiate less heat?
My instinct is that if information isn’t energy, then you could theoretically create it (thereby reducing entropy) without expending energy, and that’s a no-no.
But if it is energy, then a CPU running a random number generator (creating no information) at max load would get hotter than one doing actual calculations. Which also sounds wrong.
(I’m neither a physicist nor a computer scientist, in case that wasn’t obvious)
Information is entropy. The 80W is going out as heat, noise, vibrations, radiation.
If we could run a theoretical computer which is 100% efficient, it could compute forever with the same electrons.
Classical computers can never be 100% efficient https://en.wikipedia.org/wiki/Landauer's_principle
A quantum computer, maybe.
Reversible computing try to counter this effect. The idea is to avoid any loss of information. It does not required quantum computing.
Well yeah but quantum computers are naturally reversible.
Precisely, information has lower entropy than chaos.
Yet, it would still need extra energy to move the electons around.
Do not summon Maxwell’s Demon (in German, the English article doesn’t elaborate on this that explicitly):
Wrong, information can also be random noise.
What information is contained in random noise?
Measurements, decoherence, distributions.