> I'm not sure where your 8e9 number is coming from. Population doubling every year but the parents leaving the planet after mating?
That's the current human population.
> In your calculation, after 1000 years, there would be 2^40 humans, each weighing 100kg - many orders of magnitude less than Mercury's mass.
You start with one human, I didn't. What are you even imagining that I'm describing, Adam-only parthenogenesis?
> Still, if we give it a few thousand more years of exponential growth, you will eventually reach such masses.
Even with Adam-only parthenogenesis, log2(8e9)*25 years is 822 years, less than one, definitely not plural, millennia.
Material science isn't my field, though it doesn't need to be given how many other places there are for whichever chemicals we want. Water? Oxides in the local rock, and four massive hydrogen gas giants (don't need much proportionally as H2O is 89% oxygen by mass).
> I very much doubt your energy calculation as well, but that's already beside the point.
Gravitational binding energy of Earth: 2.2e32 J; Mercury: 1.8e30 J; Mars: 4.9e30 J; Luna: 1.2e29 J
Luminosity Sol: 3.8e26 W
Time required to explosively disassemble (i.e. each part reaching escape velocity) each object: Earth: 6.6 days; Mercury: 1.3 hours; Mars: 3.6 hours; Luna: 313 seconds.
To preempt the obvious, yes I know that's the number for total luminosity and not the power available at any given moment given how many space habs have been built part way through the process, but that makes very little difference: Given the way the functions behave, you don't need most of the power of the sun until you can harness a significant percentage of it anyway.
I mean, this toy model also assumes that the only thing these humans do with their lives is reproduction, with the average individual adding only a little more than their own body mass to the VN swarm each generation, and not, e.g., building themselves a nice little space hab that's unlikely to mass less than 10,000 kg/person even if I make the grossly simplifying assumption of just adding life support to a tiny house or a camper van. It makes very little difference to exponential growth.
You haven't addressed the most important points at all, and keep coming up with toy models based on exponential growth. All of the models ignore the realities of how mechanical things work and how they can break and how they actually operate (just for a basic example, there is no mechanical system we have any idea how to build that could move any amount of the Earth's mantle in any way, since the mechanisms would simply melt) and rely on the ridiculous idea that this exponential growth can actually be maintained indefinitely to paper over various other omissions.
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.
> just for a basic example, there is no mechanical system we have any idea how to build that could move any amount of the Earth's mantle in any way, since the mechanisms would simply melt
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.
> You know stuff cools down, right? Power loss to radiation is proportional to T^4.
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).
> I'm not sure where your 8e9 number is coming from. Population doubling every year but the parents leaving the planet after mating?
That's the current human population.
> In your calculation, after 1000 years, there would be 2^40 humans, each weighing 100kg - many orders of magnitude less than Mercury's mass.
You start with one human, I didn't. What are you even imagining that I'm describing, Adam-only parthenogenesis?
> Still, if we give it a few thousand more years of exponential growth, you will eventually reach such masses.
Even with Adam-only parthenogenesis, log2(8e9)*25 years is 822 years, less than one, definitely not plural, millennia.
Material science isn't my field, though it doesn't need to be given how many other places there are for whichever chemicals we want. Water? Oxides in the local rock, and four massive hydrogen gas giants (don't need much proportionally as H2O is 89% oxygen by mass).
> I very much doubt your energy calculation as well, but that's already beside the point.
Gravitational binding energy of Earth: 2.2e32 J; Mercury: 1.8e30 J; Mars: 4.9e30 J; Luna: 1.2e29 J
Luminosity Sol: 3.8e26 W
Time required to explosively disassemble (i.e. each part reaching escape velocity) each object: Earth: 6.6 days; Mercury: 1.3 hours; Mars: 3.6 hours; Luna: 313 seconds.
To preempt the obvious, yes I know that's the number for total luminosity and not the power available at any given moment given how many space habs have been built part way through the process, but that makes very little difference: Given the way the functions behave, you don't need most of the power of the sun until you can harness a significant percentage of it anyway.
I mean, this toy model also assumes that the only thing these humans do with their lives is reproduction, with the average individual adding only a little more than their own body mass to the VN swarm each generation, and not, e.g., building themselves a nice little space hab that's unlikely to mass less than 10,000 kg/person even if I make the grossly simplifying assumption of just adding life support to a tiny house or a camper van. It makes very little difference to exponential growth.