Question

According to Olbers's paradox, the entire sky would be as bright as the surface of a typical star if the universe were infinite in space, unchanging in time, and the same everywhere. However, conditions would not need to be quite that extreme for the "nighttime" sky to be as bright as the daytime sky.

a) Using the inverse square law for light, determine the apparent brightness of the Sun in our sky.

b) Using the inverse square law for light, determine the apparent brightness our Sun would have if it were at a distance of 10 billion light-years.

c) From your answers to parts a and b, estimate how many stars like the Sun would need to exist at a distance of 10 billion light-years for their total apparent brightness to equal that of our Sun.

Answer 1

a) The apparent brightness of the Sun in our sky is about 1.4 x 10^9 times brighter than the average star.

b) If the Sun were at a distance of 10 billion light-years, its apparent brightness

Step-by-step explanation:

I don't know c sorry