Stoney Bud said:
The sun creates 4 × 10 to the 26th watts of energy every second.
The sun's diameter is about 864,000, and its radius is thus 432,000.
Applying the formula for area gives us the following:
3.14 x 4.32 x 4.32 x 10 to the 5th x 10 to the 5th = 58.6 x 10 to the 10th or 5.86 x 10 to the 11th square miles.
Do the math, take two asprin and call me in the morning.
Stoney, Hate to have to correct you, but the sun is a sphere and the surface area of a sphere is 4 x (pi) x r x r. So if the radius is 432000 miles, the surface area is 4 x 3.14159 x 432000 x 432000 = 2.345 x 10 ^12
So, if it is putting out 4 x 10^26 watts, we have (4x10^26) / 2.345x10^12 = 1.7 x 10^14 Watts/Sq. Mile on the surface of the Sun.
The average distance of the Earth from the sun is 93 Million miles = 9.3 x 10^7. So, the (average) amount of energy that hits the Earth is:
[4 x 10^26]/[4 x 3.14 x (9.3 x 10^7)^2] = [4 x 10^26]/[1.09 x 10^17] = 4 x 10^9 Watts/sq. mile
There are 5280 feet in a mile, so there are 5280 x 5280 = 2.79 x 10^7 sq.ft/sq.mi
Therefore, there are [4 x 10^9]/[2.79 x 10^7] = 1.43 x 10^2 =
143 Watts/sq.ft of solar energy hitting the earth at noon.
So, 100 Watts/sq.foot is about right.
(Man, I've got too much time on my hands.....
)