[eurasiantiger]

That equivalence exists in the domain of classical physics.

Bitcoin only exists in semiconductor systems: its ineffectiveness stems from the extra logical layer (gates on silicon) which, while based on quantum effects, does not utilize quantum effects directly for calculation.

[AaronFriel]

This sounds like quantum woo.

If we had desktop quantum computers, and a computationally hard algorithm on qubits was used for proof of work instead, we would still end up in the same arms race of ever more expensive, ever more power hungry systems do that work.

What would happen if Bitcoins work function (the hardness) was made 10 times easier, would miners use 1/10th the power budget? No, they'd just 10x their mining rate. Why? Because other miners have every incentive to do the same.

Likewise with a quantum algorithm.

[birktj]

Isn't there also a fundamental equivalence between information and energy in physics? And so is there not a lower limit to the amount of energy required to compute a SHA256 hash of a certain number of bytes, and by extension mine a bitcoin block?

[dogma1138]

Yes but only for irreversible computation https://en.m.wikipedia.org/wiki/Landauer%27s_principle

[deepnotderp]

Even for reversible computation the Margolus-Levitin theorem has been hypothesized

[dogma1138]

Isn’t the Margolus Levitin theorem slightly different?

As in while it puts the maximum bound of amount of computation per J it doesn’t enforces a requirement that the entropy increase needs to be through a non-information degree of freedom as in heat.

[flyinglizard]

Doesn’t any method by which work is done, in a proof of work system, consume energy?

[eurasiantiger]

Locally and classically, yes. But quantum effects demonstrably break locality. Call it quantum woo if you want, but the reality is that we perceive the world top-down and know incredibly little of how our universe actually functions from the bottom up.

[dogma1138]

Isn’t a perfect computer is also a perfect heater? Quantum or not...