Imagine that you observed the Sun and measured the brightness of the face of the Sun at the locations marked in this image: At which of these locations would you measure the lowest brightness?

Question

Quizplus · Accepted Answer

The lowest brightness would be measured at point D, which is the location closest to the edge of the Sun. This is because the brightness of the Sun decreases towards its edge due to the decrease in temperature and density of the gases in the outer layers of the Sun. Therefore, the light from point D has to pass through more of the outer layers of the Sun, which results in more absorption and scattering of the light, and hence lower brightness.

Imagine That You Observed the Sun and Measured the Brightness