michael_nielsen

I reject the idea that energy consumption is inherently bad. We want more energy for everyone. Energy is freedom. You could measure economic and social progress largely by the useful energy individuals have at their disposal.

On this topic, most ppl yet again wind up nostril-deep in the intellectual tarpit dubbed Goodhart's Law While true that not all "energy consumption" lands on the "good" side of things, to avoid this tarpit consider another framing: To consume no energy *would be* inherently bad

If we're talking about security of cryptocurrency, no, energy consumption is a cost to be reduced. It's not a positive factor in any way. Computation with no power consumption is physically impossible, but minimizing energy consumption is a goal - not a metric getting gamed.

Reversible computing can be used to do computing with (in principle) zero energy consumption.

The proof is usually attributed to a 1973 paper by Bennett, but I particularly like the explanation of Fredkin and Toffoli and their billiard ball model of computing: http://fab.cba.mit.edu/classes/862.16/notes/computation/Fredkin-2002.pdf …

Yes, my bad. @anderssandberg and @robinhanson have pointed this out to me, and I should have remembered. I definitely don't understand the physics yet, but thanks for pointing to the paper - it looks like it might be a clearer explanation than I've yet seen. But the point stands:https://twitter.com/davidmanheim/status/1083645585784299520 …

Section 3.6 has a model which is just billiard balls rolling round a table, doing universal computing. No energy consumption at all. It's a very nice model, albeit not physically practical.

In general, there will be noise in models like this, and some energy dissipation is required to remove it through error-correction. But there's no in principle lower bound to that noise.