A student claims that because of atmospheric refraction, the sun can be seen after it has set, and the day is, therefore, longer than if the earth had no atmosphere.
(a) What does the student mean by saying that the sun can be seen after it has set?
(b) Do you think that the students' conclusion is correct?
The student mean by saying that the sun can be seen after it has set, is due to the atmospheric refraction we continue to see the sun about two minutes after the actual sunset. This is because earth has atmosphere which cause refraction and this is the reason for having longer day.
(b) Yes, the students conclusion is correct.