The pupil of the human eye is approximately 0.8 cm in diameter when adapted to the dark. The ratio of the light-gathering power of a 1.6-m telescope to that of the human eye is ____.

Question

Quizplus · Accepted Answer

The light-gathering power of a telescope is proportional to the area of its aperture. The area is proportional to the square of the diameter. The telescope's diameter is 1.6 m (160 cm), and the eye's diameter is 0.8 cm. The ratio is (160/0.8)^2 = 40,000.

The Pupil of the Human Eye Is Approximately 0