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Viewing Single Post From: The giant space ship example
Chris Ho-Stuart
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This example is due to "Gbaikie", in a comment at the Climate Etc blog. (Here is a link to the original comment.) I think this is a very well-conceived problem, so I am putting a copy here. I have rephrased a little; but using Gbaikie's original comment as the basis for this topic. Thanks, Gbaikie!

Suppose you wanted to travel to a different star system and your starship was going to be a moon size body.

The propulsion method is not important. You might, perhaps, use a lot of nuclear bombs for propulsion, so this moon size object might be a giant Orion nuclear starship. (See Project Orion (nuclear propulsion) at Wikipedia.) We will assume that somehow it can be made to go at perhaps 1/10th the speed of light, and so takes quite a while to get to another star system.

Suppose it is about the size of the largest known Kuiper belt object: Eris, about 2400 km in diameter. (Ref: largest Kuiper Belt objects.)

My question isn't where it's going or how nukes are needed to get to 1/10th light speed, but rather: how much heat would be needed to heat an atmosphere? The atmosphere could be rather low in pressure compared to Earth, but high enough pressure so people could use oxygen masks rather than pressure suits. Let us suppose a pressure similar to Earth at 8 km altitude (similar to the top of Mt Everst) , or 5 psi.

There will be no sunlight for most of trip and idea is to have air pressure about 5 psi and temperature about 10 C at the surface. The air will heated with fission nuclear furnaces; so heating the moon as one would a house, only on vastly larger scale.

Assume it has 1/10th earth gravity, and 1/3 the surface air pressure.

Given the temperature, air pressure, surface gravity and size... how much energy would be lost to the black universe?
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The giant space ship example · Physical theory for climate