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.
Watch the Bartlett lecture.
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.
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.
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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.