Space/Science — HabitableZone

Space/Science » in reply to re: It depends whether it is IMPORTANT or not

DUH, get a scientiufic education
nick hoffman — (archived)

when I said watts I meant WATTS.

Solar energy impinging on a perfect flat plate at the Earth's distance is worth 1360 W/sq m. This is at noon, if you're a planet and have marked a square metre of its surface (and it's midsummer and you're at the equator).

Now, there is night and day, the earth is curved, and there is summer and winter. I thought that everybody understood about these things. The nett effect of them is to share out the 1350 W/sq m that would hit a theoretical 2D paper cut-out Earth over its real 3D surface. So you need to know the surface area of a a flat circular disk and a sphere.

The disk is PI * R^2. the sphere is 4 PI * R^2, so the sunlight, on average, is only 1/4 as strong when you include night, winter, lattitude...

So our nominal 1360 W/sq m becomes 340 W/sq m, averaged over time and space.

The heat flow is an average as well. Apples and Apples...

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