You know stuff cools down, right? Power loss to radiation is proportional to T^4.
> You also don't need to be a materials scientist to know that you can't get water or oxygen out of rock with sheer mechanical force.
Good thing you're putting words into my mouth, then. Hint 1: How do we do this for aluminium? Hint 2: I didn't say "mechanical" for this.
> Your estimate for the energy of the sun takes into account all of the energy sent in all directions in all spectra
I know, and I said as much with different words.
Do you perchance know what a mirror is? Or how light they are? How little of (insert-planet-here)'s mass you need to turn into PV and/or mirrors to get to covering the planet, how little time it takes to use those to gather the energy needed to run a launch loop to get a second planet-tiling-quantity to orbit?
That's why I preemptively made the point that you're ignoring here.
It only took around 160 million years for the Earth's crust to form, so yeah, sure, stuff cools down, eventually.
> Hint 1: How do we do this for aluminium? Hint 2: I didn't say "mechanical" for this.
Ok, mechanical was my idea - but chemical extraction of oxygen requires some other compounds to form, potentially making the whole thing even less usable for future conversion into more copies. Plus, it requires an input of some other materials, which may not be easy to create.
> Do you perchance know what a mirror is? Or how light they are? How little of (insert-planet-here)'s mass you need to turn into PV and/or mirrors to get to covering the planet, how little time it takes to use those to gather the energy needed to run a launch loop to get a second planet-tiling-quantity to orbit?
That still only gives you the 10^15 watts that reach the Earth, not the 10^26 number you were citing. Also, covering the whole planet with mirrors or PVs is again not nearly as trivial as you make it out to be, and this "launch loop" idea is just some abstract design, not something we can actually build (despite what the author would have you believe).
You also don't need to be a materials scientist to know that you can't get water or oxygen out of rock with sheer mechanical force.
Your estimate for the energy of the sun takes into account all of the energy sent in all directions in all spectra. The amount reaching the earth is significantly less - 1.73e15 W, or about 10^9 times less - and the amount that can realistically be captured is far less than that.
Overall, don't worry: there is exactly 0 chance that any human advancement will disassemble even a dwarf planet in the next millennium in the real world. Just because Freeman Dyson could write some back of the napkin computations it doesn't mean this is actually possible in any meaningful way.