How many times more light can the 10-m diameter Keck telescope on Mauna Kea in Hawaii collect than an average unaided human eye, which has a typical aperture diameter of 5 mm?

Question

Quizplus · Accepted Answer

The amount of light collected is proportional to the area of the telescope aperture. The area of the Keck telescope's aperture is (10 m/2)^2 x pi = 78.5 m^2, while the area of the human eye's aperture is (5 mm/2)^2 x pi = 1.96 x 10^-5 m^2. Therefore, the Keck telescope can collect (78.5 m^2)/(1.96 x 10^-5 m^2) = 4 x 10^16 times more light than an unaided human eye.

How Many Times More Light Can the 10-M Diameter Keck