For temperature reasons, a complete Dyson sphere is likely to be built outside the earth, as the energy output of the sun would force one at 1 A.U. to be 393K = 119 C. I assume the AI would prefer not to run all of its components this hot. A sphere like that would cook us like an oven unless the heat dissipating systems somehow don’t radiate any energy back inwards (which is probably impossible).
A Dyson swarm might well be built at a mixture of inside and outside the earth’s orbit. In that case the best candidate is to disassemble mercury, using solar energy to power electrolysis to turn the crust into metals, send up satellites to catch more sunlight, and focus that back down to the surface.
Mercury orbits at 60 million km from the sun. This means a circumference of 360 million km. The sun is 1.2 million km across, but because it’s at 0.38 au from the sun, a band which blocks out the sun for the earth entirely would only need to be 0.8 million km. This gives a total surface area of 290e12 square kilometers to block out the sun entirely. Something like a Dyson belt.
If the belt is 1 m thick on average, this gives it a total volume of 290e18 cubic meters. Mercury has a volume of 60 billion cubic km = 60e18 cubic meters. This would blot out approximately 1⁄5 of the sun’s radiation.
To put things in perspective, Mars is kinda maybe almost habitable with a lot of effort and gets less than 1⁄2 of the sun’s radiation. I would make a wild guess that with 80% of the solar radiation we could scrape by with immense casualties due to massive decreases in agricultural yield. Temperature is somewhat tractable due to our ability to pump a bunch of sulfur hexafluoride into the atmosphere to heat things up.
As a caveat, I would suggest that if the AI is “nice” enough to spare Earth, it’s likely to be nice enough to beam some reconstituted sunlight over to us. A priori I would say the niceness window for “unwilling to murder us while on earth, and we pose a direct threat, but unwilling to suffer the trivial cost of keeping the lights on” is extremely narrow.
As a caveat, I would suggest that if the AI is “nice” enough to spare Earth, it’s likely to be nice enough to beam some reconstituted sunlight over to us.
Yeah seems right. I still find myself curious, as well as strategically interested in “man, I just really don’t know how the future is likely to play out, so getting more clarity on physical limits of this sort of system feels like it helps constrain possible future scenarios.” That might just be cope though.
Ooh boy this is a fun question:
For temperature reasons, a complete Dyson sphere is likely to be built outside the earth, as the energy output of the sun would force one at 1 A.U. to be 393K = 119 C. I assume the AI would prefer not to run all of its components this hot. A sphere like that would cook us like an oven unless the heat dissipating systems somehow don’t radiate any energy back inwards (which is probably impossible).
A Dyson swarm might well be built at a mixture of inside and outside the earth’s orbit. In that case the best candidate is to disassemble mercury, using solar energy to power electrolysis to turn the crust into metals, send up satellites to catch more sunlight, and focus that back down to the surface.
Mercury orbits at 60 million km from the sun. This means a circumference of 360 million km. The sun is 1.2 million km across, but because it’s at 0.38 au from the sun, a band which blocks out the sun for the earth entirely would only need to be 0.8 million km. This gives a total surface area of 290e12 square kilometers to block out the sun entirely. Something like a Dyson belt.
If the belt is 1 m thick on average, this gives it a total volume of 290e18 cubic meters. Mercury has a volume of 60 billion cubic km = 60e18 cubic meters. This would blot out approximately 1⁄5 of the sun’s radiation.
To put things in perspective, Mars is kinda maybe almost habitable with a lot of effort and gets less than 1⁄2 of the sun’s radiation. I would make a wild guess that with 80% of the solar radiation we could scrape by with immense casualties due to massive decreases in agricultural yield. Temperature is somewhat tractable due to our ability to pump a bunch of sulfur hexafluoride into the atmosphere to heat things up.
As a caveat, I would suggest that if the AI is “nice” enough to spare Earth, it’s likely to be nice enough to beam some reconstituted sunlight over to us. A priori I would say the niceness window for “unwilling to murder us while on earth, and we pose a direct threat, but unwilling to suffer the trivial cost of keeping the lights on” is extremely narrow.
Yeah seems right. I still find myself curious, as well as strategically interested in “man, I just really don’t know how the future is likely to play out, so getting more clarity on physical limits of this sort of system feels like it helps constrain possible future scenarios.” That might just be cope though.