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Guest426 t1_isyngeu wrote

Reply to comment by humblyhacking in Is our sleep pattern based off the length of the day? by ebb5

Humans as all warm blooded creatures generate heat and the planet has a limited capacity to reject that heat - thermodynamics dictate that the Earth has a limited carrying capacity for humans. This is putting aside all the pollution that you mentioned that we create, which will likely kill us way before we cook the planet with our farts and sweat.

Gravity doesn't need to be fought. Spin up a cylinder of 500m in diameter at 2 rpm and you have earth gravity. Luckily, in space that cylinder will keep spinning.

For radiation shielding - 5m layer of dirt (formed from asteroid mining slag) solves that issue.

Saying we will never live in space is like saying we will never: circumnavigate the globe, fly or go into space.

Sadly, living in space is easier to imagine than everyone throwing their plastic bottles in the trash and not on the ground.

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dynamictype t1_it0gmky wrote

Isn't all the heat human bodies generate derived from the sun? If humans weren't here, the heat that gets stored as energy in sugar, muscle, fat etc would instead just turn to heat immediately. We aren't creating heat from nothing.

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Guest426 t1_it2e9qf wrote

Correct, however.

Energy in = energy out + energy stored

When the Sun is creating sugar the Earth can reject the remaining heat. But when we start converting that sugar into heat, the Sun does not turn off, it keeps supplying the same amount of heat as before. So now if we take the constant supply of heat from the Sun and we add the conversion of stored sugar energy into heat, without increasing the Earths capacity to reject heat, at a certain rate of sugar burning we will overwhelm the Earth's heat rejection capacity and the internal temperature of the system will rise.

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dynamictype t1_it2fd5g wrote

But we're planting plants and raising livestock. As humans expand we're the ones adding more stored energy. The net energy is still the same. Every bit of sugar burned was heat saved earlier in the growing season.

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Guest426 t1_it2jsv7 wrote

But as we burn that sugar, the Sun keeps supplying the same amount of heat as it was while the sugar was being created.

Imagine a river, a damb and a reservoir.

The river flows to the reservoir and through the damb. All of the water came from the river, but if we release too much from the reservoir at once, the damb will overflow.

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dynamictype t1_it2n236 wrote

But the sugar absorbed the energy when it was grown

It's net zero. We can't be generating more heat than the sun is supplying, that breaks the conservation of energy. It's like the fallacy in The Matrix that humans could generate energy via body heat. It's always zero sum.

If I grow corn in June, the corn is absorbing the heat from the sun and converting to sugar. The net effect of growing corn reduces the total heat of the Earth.

When someone eats the corn and their body temp is increases the heat is released. Since all across the earth we are pretty much constantly growing and eating this mostly all evens out. And even if it's not perfectly even, due to seasons, you still over the course of the year have net zero heat vs if humans didn't exist at all.

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