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quettil t1_jdz9w2d wrote

Reply to comment by MrZwink in Would building a Dyson sphere be worth it: We ran the numbers. by filosoful

Depends on how dense and wide it is. If you have it close enough to the sun you wouldn't need much material.

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MrZwink t1_jdzawix wrote

Ye I've read papers with the math on this.

If just a few milimeters thick, you would still atleast need mercury and Venus. Remember the sun is hot, so you can't go to far in. You'd think getting a lower energy output star would help, but brown dwarves and red dwarves have unstable ejections and radiate making them unsuitable.

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quettil t1_jdzcby8 wrote

A 1mm thick swarm at 0.1AU would need around 7% of the mass of Mercury. It's supposed to farm energy from the Sun so it has to tolerate heat. And just 1% of this is a trillion times Earth's current energy consumption.

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MrZwink t1_jdzcnb1 wrote

You're assuming all the materials are useful. While infact you need metals. Luckily mercury has an iron core. And we were talking Dyson sphere not swarm. A swarm would be much easier, as it requires much less material, much less stabilisation. And you can construct it a segment at a time.

A Dyson swarm at 0.1 au would also be very toasty.

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quettil t1_jdzcrro wrote

> And we were talking Dyson sphere not swarm.

A Dyson sphere is a swarm. Sphere is a misnomer. It was always a swarm.

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MrZwink t1_jdzde4a wrote

Friedman Dyson proposed an actual sphere. But in practice the sphere would be very difficult to keep in orbit. A small imbalance and it would destabilize and fall into the sun.

Swarms are much more easily executable.

They are not the same thing.

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