Using energy for the sake of using energy is pretty dumb. You can try to sugarcoat it all you want, but that’s just how it is.

Just the other some tourist came by in a helicopter, landing in a next-door field to take some visiting friends for a flip. They'd rented the chopper for the day as some sort of perverse idea of an adventure. Complete waste of energy, dumping C into the atmosphere in the cause of their inflated ego and distorted sense of entitlement, but hey...

How is this any different?

(Point being, there are many, many activities people engage in that are a complete waste of energy. Should PoW cryptocurrency mining be singled out for particular excoriation? Personally I'm against it for the exact reasons mentioned along with the reality that Bitcoin has failed in its mission. But let's not pretend it's the only thing we should stop doing.)

I've written a comment in a similar previous thread on why bitcoin / PoW's energy usage is different from other seemingly wasteful uses of energy. That was over here: https://news.ycombinator.com/item?id=29367100

Not to repeat it in full, but the short of it is that bitcoin's usage of energy is not for the amount of energy, but because it must expend a certain economic value of energy in order to keep the network secure. If energy becomes cheaper or more efficient, bitcoin must burn more. Bitcoin's energy usage has an adversarial relationship with efficiency. Practically every other use of energy does not have an adversarial relationship, and will accept the same total amount of cheaper energy to do the exact same work with no complaints.

A helicopter will not require twice as much gas to fly the same distance if we happen to make gas twice as cheap.

As a result, yes I think we should single out PoW.

It's not! Everything you do wastes energy to some extent, the question is how much, and what you're getting out of it. The reason people are mad at crypto is that the benefits are marginal (I mean, it's some fraction of how our money changes hands. Some people have fun with it. I'm fine with being generous, but its benefits are super concentrated and I agree that it's not really very good at its mission of decentralizing currency or whatever) and the energy usage is massive. I mean, there are other things that use a lot of energy too: cars, planes, manufacturing, etc. but we do call them out for it, and when a company says they're committed to the environment and does some token "green" work we hold them to the same standard. The reason you just hear about cryptocurrency more here is that, well, this is a technical forum where it's a frequently encountered topic.

PoW isn't using energy just to use energy. It's using energy to validate a block of transactions in a distributed, untrusted network.

I understand how proof of work works. That’s not what was being discussed here, the point was that justifying proof of work as being a catalyst for clean energy is just stupid, because proof of work has nothing to do with clean energy, it just uses a monumental amount of it and wants to greenwash itself with promises of potentially being clean to justify its continued existence. Like, it’s like people living next to a lake and drinking from it and feeling uneasy that the water might not last if they keep using it, and then you come by and start slurping up half of it, and when people complain you point at some small fraction of the water you’re using coming from desalination or something. Except you don’t care about desalination at all, or even the lake, you just want water cheaply to use massive amounts of it and when people come to you and say you are using massive amounts of water you don’t even stop using the massive amounts of water but instead point at your dinky little desalination plant, which doesn’t do anything in the grand scheme of things and people were working in doing anyways, plus news just came out pumping water on the other side of the lake is even cheaper and the enforcement on how much water you can take from it laxer and you were photographed over there taking all their water too, so yeah. Kind of sick of this argument being pushed at all, and it has nothing do with how blockchain works.

It is using energy just to prove that you’ve used more energy than an attacker is presumed to be able to use. If our energy suddenly became 1000× cheaper and greener, then the mining difficulty would increase by 1000×, and the system would remain equally destructive. And there would be no benefit from this 1000× increase in energy usage—this would not enable more, faster, or cheaper transactions. Just hash values with more zero bits to certify that more energy was used. If that doesn’t qualify as “using energy just to use energy”, then nothing does.

You may be missing the point on security and energy. Think adversarially. If the energy was 1000x for me, it’s 1000x for my adversary too. It’s important that we outspend the adversary if we want secure money.

Yes I know why PoW has to work that way. I explained that in my first sentence. The fact that a PoW system requires honest participants to waste more energy than attackers could in order to function doesn’t make it any less wasteful.

> It’s important that we outspend the adversary if we want secure money.

Money has been secure for literally thousands of years before PoW was invented. Sure, PoW works, but it's the most wasteful solution to the problem of securing transactions that has ever been invented in the history of the world.

Well, money isn't secure in the sense that it doesn't protect you against inflation like bitcoin does; also, the money in the bank can be taken from you while you can really own cryptocurrencies.

Nothing stops a democratic country from deiciding they don't want to accept inflation in their fiat currency, just like in Bitcoin. The reasons this isn't done are complex, having some amount of corruption but also knowing that printing money is the only known way of getting out of a deep economic crisis, like the great depression.

And Bitcoin will not protect anyone from non-financial inflation, such as rising energy prices causing a rise in prices for most other goods. If anything, Bitcoin would make kt harder to actually transact in this type of market potentially leading to problems of simply there not being enough money for the economy to function.

Finally, while Bitcoin may give some protection from a hostile government, it also leaves you with no protection for much more common cases of fraud, forgotten/destroyed passwords etc. Not to mention, most people transact Bitcoin through an exchange, the equivalent of a bank, which could probably be forced to cede control of "your" wallet to a government just as much as any other financial institution.

No, it isn't. "Validating" a transaction takes very little energy -- in most cases, it's a simple ECDSA signature check.

What's being "validated" by PoW mining is that someone has done a bunch of expensive, energy-intensive work on a block of transactions to satisfy an arbitrary condition (that a hash of the block be less than a target value). Explaining how this actually "secures the transactions" involves a great deal more hand-waving.

No hand waving. One needs to outspend the energy (hash rate of the network) to undo transactions, censor or reorder transactions. The (probabilistic) finality of the transactions is contingent on the energy spent. It’s not a complex idea.

Bitcoin's hashrate has dropped by 50% a number of times and no transactions have been undone, censored or reordered. This is pretty solid evidence that at least a large percentage (if not all) of the energy spent by bitcoin is wasted.

Sure, but that goal in itself is dubious at best. And, PoW is using the maximum possible amount of energy to achieve such a goal.

It's basically like heating your home by adding CPUs in your walls and having them compute the digits of Pi instead of running current through a resistor, because you don't want to have to trust Big Resistor.

The bitcoin network is far more centralized than traditional payment systems, many orders of magnitude slower, and it uses as much electrical energy as entire countries to achieve this.