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Comment by knolan | Hacker News Reader

I’m always amazed how little ambition proponents of perpetual motion machines have. They always talk about not having to pay their energy bill or charge their smartphone ever again. Here in Ireland we had Steorn[0] which resulted in much amusement at the time. I still remember their failed London demonstration where their device refused to work due to the heat from the lights…

However, if you can generate free energy then you are like a god. You can use chains of even the most crappy perpetual motion machine to generate infinite energy and construct the most fantastical machines, who cares how much energy they consume! You could conquer planets and command your own vast galactic empire. You are only limited by your imagination since infinite energy is available to do whatever you desire.

[0] https://en.m.wikipedia.org/wiki/Steorn

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You forgot about power, size, and cost.

I can create a device, which will harvest 1W of power from starlight infinitely. Good luck with your ambitions.

We’re not talking merely scavenging energy here. We’re taking about a perpetual motion machine that gives more out than you put in. I feed it 1 W and I get maybe 1.000000001 W out. Maybe it’s big and cumbersome but the principle, if like all the supposed devices to date, is probably some clockwork arrangement of magnets so it could be made more compact. Maybe it produces slightly less free energy who cares as long as it outputs more than I put in.

I connect many of these together and eventually I have 1.1 W from my 1 W input. I can keep going in this manner, at some expense sure, but now I’m producing 2 W per 1 W input. The effect must be cumulative if the device is truly a perpetual motion machine.

It will cost me less to mine resources giving me economic advantage. Eventually as I build more energy production capacity it will cost me nothing. I can harvest as much raw material as I need and fabricate whatever machines I want at zero cost. Currently this only limited by wealth but in my free energy utopia I’m unconstrained except by availability of material resources, I have infinite energy.

So I build a lumbering ship unconstrained by the limitations of mere rockets and mine the planets. I can build a planetary civilisation from this. I have enough energy, mechanical and computational power to do this easily. I now need to devise a means to achieve interstellar travel. But I have infinite energy, therefore infinite compute and near limitless material resources across the solar system.

Because of the promise of perpetual motion and free energy the effect snowballs at every step.

Reductio ad absurdum

Black hole? Throw mass into a black hole, to generate energy, and increase mass of the black hole, to generate even more energy.

Most perpetual motion machine inventors think like engineers with some understanding of Newtonian mechanics. So practical stuff like gears and pulleys and magnets. Thinking at the scale of a black hole isn’t usually their area.

Thing they don't get is gravity is not energy. It's not even a force.

Gravity can generate motion and one can extract energy from it. But in general some effort is required prior (like sun energy that fills up dams which later use gravity to generate hydroelectricity.

Gravitational motion is not perpetual, either. Water flows towards the center of the massive object curving space-time and that's it. It won't flow in a cycle. Unless some other factor spends energy making it flow, i.e. the Sun.

So a stationary generator that has no external energy input to keep motion flowing connected to gravity cannot generate energy.

You'd probably go to jail for trying to operate your own power generation plant. Curious thought process, how succeed given an infinite power machine. I'm sure I'd manage to fumble it.

You can fumble as much as you like. It doesn’t matter how crazy your vast ostentatious space palace is or how inefficient it is, you have infinite energy. You therefore have infinite compute. You won’t even need to think.

> You therefore have infinite compute. You won’t even need to think.

Peak HN.

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