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Comment by bryanrasmussen | Hacker News Reader

there was a quote, and I can't remember exactly so I paraphrase: "the person who creates a new form of energy for the world, without creating an equivalent heatsink, would be history's greatest monster", although I suppose that is very perfect being the enemy of the good.

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Isn’t this why solar is good. We already have the heat sink (earth) we just aren’t using the energy.

Not exactly because the Earth naturally reflects a large amount of solar energy back into space.

A lot of that is from clouds that are above the panels

That's more of the solution than the problem. Most of the light is absorbed rather than reflected, but causing more to be reflected isn't that hard, e.g. cover a large surface area of low value land or ocean with cheap reflective material.

I don't think that is "very perfect being the enemy of the good" at all. Any new energy source (like fusion) would be a very real threat to mankind, see also https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...

He very early assumes/disregards we remain confined to earth. In the face of exponentially growing energy resources, this is a terrible assumption.

Do you imagine we will box up our terrestrial waste heat and launch it into the sun?

The portion people who leave the Earth do not matter, the fate of the portion who remain remains the same.

See "Arithmetic, Population and Energy: Sustainability 101", Al Bartlett

https://www.albartlett.org/presentations/arithmetic_populati...

Full length video: https://www.youtube.com/watch?v=sI1C9DyIi_8

The point is that you can have exponential growth in human energy consumption without exponentially heating the Earth by having the growth take place off-planet. Which is hardly irrelevant to the people still there, e.g. if you find your data centers are using too much power, put them in space. The computation may take a megawatt-hour but transmitting the result back to the surface is only a few watt-seconds for a radio link.

Likewise, the humans who live on other planets can be consuming local energy without heating Earth, and the people still on Earth would still get the value of their inventions, discoveries and writings.

> you can have exponential growth in human energy consumption without exponentially heating the Earth by having the growth take place off-planet

No. It doesn't matter, unless you postulate that the people left behind have zero population growth and constant energy dissipation, which seems unrealistic?

In any event exponential growth in human energy consumption is physically unrealizable. Eventually the whole solar system resembles a red giant star, and sooner than you might think.

- - - -

The point is that anyone who good enough at physics to invent a free energy generator also understands why it must be kept secret. Some secrets keep themselves. That's why you can't buy one even though there are videos on the YT showing how to make them. Like the Philosophers' Stone the point of the technology is the internal transformation it engenders when you actually confront the thing itself.

> It doesn't matter, unless you postulate that the people left behind have zero population growth and constant energy dissipation, which seems unrealistic?

Why does it seem unrealistic? More than that, you only need one of those things. You could have population growth with declining energy consumption if energy use is moved off-planet (even if the population benefits from the off-planet use), or increasing local energy use per-capita if local population is declining, e.g. because the number of people leaving to explore other planets is higher than the population growth rate.

> Eventually the whole solar system resembles a red giant star, and sooner than you might think.

The universe is a lot bigger than the solar system.

> That's why you can't buy one even though there are videos on the YT showing how to make them.

Uh, nope. That's not why you can't buy one.

At this point we're just trading sci-fi story ideas. If we can learn to manage our population growth and/or energy consumption growth, then that's awesome!

Watch the Bartlett lecture.

The original claim was essentially that energy use can't increase past a certain point because it would result in too much energy density. The obvious flaw in the claim is that it assumes no ability to increase the volume of space in which the energy use takes place, which is an invalid premise. Space is really big.

No, dude, even if you postulate FTL spaceships, the size of the Universe doesn't matter, you always eventually become an explosion. All exponential growth curves are S-shaped.

At this point I'm just repeating basic physics and math at you. I think we both have better things to do with our time. Have a good day.

Yeah, Ehrlich will be right any day now. Just you watch . . .

We don't even know for sure that the universe is finite. You're going to run out of hydrogen before you run out of somewhere to put the heat.

> e.g. if you find your data centers are using too much power, put them in space.

…put them in space how far away from Earth exactly? If they're too close, the heat they radiate away will end up on Earth again. If they're too far away, latency & maintenance will become an issue.

> If they're too close, the heat they radiate away will end up on Earth again.

So put a mirror on the Earth side of it?

> If they're too far away, latency & maintenance will become an issue.

There are many compute tasks where latency is irrelevant. To take a recent example, AI model training. It does not matter if the compute farm is a few light minutes away when the computation itself is going to take days to months.

Maintenance is performed locally. It's not as if you're going to have Earth and then a single solitary server farm on the far side of the Sun. By the time this becomes relevant to planetary energy there are multiple space stations with permanent staff.

> Maintenance is performed locally. […] By the time this becomes relevant to planetary energy there are multiple space stations with permanent staff.

It seems whether or not you can keep maintenance staff close-by would depend on the temperatures of those server farms. Yes, the regime in which this could work might be fairly large but remember that we're talking about exponential growth of energy production here and the whole reason behind moving the power plants (and server farms) to deep space was that they were emitting enough heat to affect planet-level thermodynamics.

But that still doesn't affect energy density. If you want twice as many server farms then you build twice as many space stations in twice the volume of space and the energy density remains constant.

> But that still doesn't affect energy density.

But it does? I think you're confusing energy density with power density. The former is an integral over time and would be monotically increasing with time since nuclear fusion would allow us to basically pull energy out of of thin (ok, maybe not so thin) air.

> Do you imagine we will box up our terrestrial waste heat and launch it into the sun?

The Earth sheds its own heat into outer space via black body radiation, and we can help this process by shedding heat in specific infrared bands that pass right through the atmosphere. We already have radiative cooling paints that do this, and they can achieve sub-ambient air temps in full sunlight:

* https://www.sri.com/fcd_technology/self-cooling-paint-a-pass...

* https://cera.cool/

* https://hackaday.com/2023/07/03/cooling-paint-you-can-actual...

Yes, and those are really cool and I want some.

We might be able to somehow collect heat (with superconductors? I don't know) and beam it into space, but that still doesn't solve the problem.

Please watch the Bartlett lecture, please?

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