Hacker News Reader

Comment by breuleux | Hacker News Reader

> What about the ten thousandth one? Will "a nuclear fusion plant" become something that models couldn't possibly get wrong?

For what it's worth, ten thousand terawatt fusion plants probably approaches the level at which the sheer intensity of energy production would cause significant disruption to the climate (it's roughly 5% of the Earth's entire solar input). Every energy source becomes dirty past a certain point. It would be wiser to learn how to build a utopia within a limited energy budget than find a way to produce enough of it to cook the damn planet, but who am I kidding, we're going to build a million of these things.

View on HN

If we had such arbitrarily large amounts of energy to handle, it would be conceivable to beam excess energy into space. It is a bit on the sci-fi side, but so is that kind of energy production.

This assumes other technological breakthroughs don't also happen in parallel. I'll go out on a limb with nothing more than a hunch that we are in the beginning stages of understanding mathematics, physics, and biology.

Yeah, maybe AI will figure out that thermodynamics is actually not real!

It does not. This is basic thermodynamics. Unless we are using computers made out of something other than matter, powered by something other than energy, thermodynamics bounds us all.

Past that is believing in magic.

Ok, but what if the AI figures out a new thermodynamics? A completely new thermodynamics, that's vastly more powerful than human thermodynamics, but of course humans won't be able to comprehend it, because it's so much more powerful, that you need the superintelligence to handle it. With a thermodynamics like that, anything could be possible, and remember: what we have now is the worst it will ever be.

This assumes we're still building them on Earth.

Why would we have stopped?

Humans seem deeply tied to Earth in ways the AI that's to be designing these powerplants is not.

We're not going stop doing something locally just because we can do it in space. There are definite physical advantages to producing next to consumption. We will most likely do both -- things that can be done in space will be done in space, and things that are better done locally will ramp up. There is no upper limit to energy demand, none whatsoever. Stopping production anywhere it could theoretically happen is a matter of will.

No, it doesn’t. It assumes we’re using it here. If we beam the power to Earth from space, it’s the same thing.

We use it in space too, we just send food and manufactured products down the elevator.

You aren't really trying in good faith to think this through are you? This idea is over half a century old. Not getting it by now is willful.

The more I think about space elevator, the less I believe in it.

The material alone is in a quantity beyond what we can reasonably manufacture.

and the material needs to be perfect. All design we have today have cascade failure mode -- any material failure translates to a total catastrophic failure.

and geostationary does not really meant Geostationary. There are lots of jiggling everywhere. It wear down over time. and let's hope nothing resonance

and we need some maintenance / decommission plan. How can we decommission this when it fail or need upgrade?

It's quite possible that with "infinite" energy we could do mass scale carbon capture to offset the increased temperatures by rolling back the greenhouse effect.

The greenhouse effect is not what's cooking the planet in this example, it's the heat that results from turning all that energy into work.

This is basic thermodynamics, not greenhouse gases. If you put some amount of energy into a system with a fixed surface area, you will get a minimum equilibrium temperature.

Greenhouse gases and Earth’s internal nuclear decay engine make the situation worse, but even without them this would boil the oceans.

Even today we're recognizing that compute does not need to happen here.

When we're talking about creating powerplants equal to roughly 5% of the insolation of Earth, I think we're sci-fi enough to discuss orbital datacenters or Mars datacenters or Jupiter fusion candle datacenters.

Compute doesn't need to happen here, but it can, so it will. Building datacenters on Mars or Jupiter doesn't reduce our ability to build datacenters here, so naturally, they will still be built, everywhere that they can be. It's an orthogonal capability.

Maybe, but there are counterexamples today. The processing of raw materials can be done all over the world, but it's not. Modern nations actually disassemble their blast furnaces and ship them out at a certain point.

Orbital datacenters suffer from the same problem: limited surface area. You think cooling is a problem now? Try not having conduction or convection. Radiation is all you get. A huge proportion of the mass and size of the ISS is radiators, and that only has to deal with the heat of low-power electronics and a few measly human beings.

Using an entire Mars only nets us about a 2x multiplier for our energy expenditure budget. Then we need four planets to double it again. Exponential growth is a bitch.

Thermodynamics and the tyranny of exponential growth are going to win this battle every time, regardless of the unobtanium technology you try to invent.

Not quite the same problem, because only a small portion of that energy radiated from space will make it back to the environment on Earth. For convection that is 100%.

> Using an entire Mars only nets us about a 2x multiplier for our energy expenditure budget.

We don't need to care about cooking Mars.

> Not quite the same problem, because only a small portion of that energy radiated from space will make it back to the environment on Earth.

I’m assuming you care about melting the GPUs in your orbital datacenters.

> We don't need to care about cooking Mars.

I’m assuming you care about melting the GPUs in your Martian datacenters.

That is not the problem being discussed. Radiators can be scaled up, but the thermal mass of Earth is finite. GPUs can survive at temperatures the organisms of Earth cannot.

I am quite certain that you are drastically underestimating the scope of the problem of "getting rid of heat" when you're dealing with the discussed levels of power production.

Maybe, but that's a "simple" resource problem. The Earth radiates 20x more heat than that today, and it has not been optimized for purpose. Remember that the initial assumptions were that AI has already designed and manufactured tens of thousands of these plants.

The problem at hand is not just getting rid of heat however, it's getting rid of heat without cooking the Earth. I still fail to see how generating the heat off planet fails to solve that.

Reply on news.ycombinator.com