4 ms·
Eventually, yes, but I don't think that's what they meant. The universe is far from thermal equilibrium :) If you push a stone up a hill, then some of the calo
by MathMonkeyMan 2y ago
Eventually, yes, but I don't think that's what they meant. The universe is far from thermal equilibrium :)
If you push a stone up a hill, then some of the calories you burned went into the gravitational potential energy of the stone, and some up it was lost as heat.
If you compute the SHA hash of some string, then some of of the energy from the power supply went into switching the voltages in transistors, and some of it was lost as heat.
- zamfi 2y agoHmm, these aren't quite the same though, are they? I was under the impression that ultimately none of that voltage change ends up as anything other than heat. (Despite voltage being "electric potential", that's only really meaningful in e.g., capacitors and batteries, not in circuits that keep switching.)
- MathMonkeyMan 2y agoThey differ in the sense that it's easy to imagine how you can reclaim the energy in the stone -- let it roll back down the hill. It's harder to imagine how you can reclaim the energy of the computation. Overwriting a bit requires a little energy even in principle, and then you can't get it back. Maybe this is what the commenter I was replying to meant by "all energy generated ends up as heat." Even still, I'm tempted to make the distinction between the energy that is needed to perform the computation and the energy that is lost e.g. to Joule heating.
- HPsquared 2y agoAnd life itself is never at equilibrium. It's all about gradients, kinetics and transfer processes.