Question

Explain this common observation clearly : If you look out of the window of a fast moving train, the nearby trees, houses etc. seem to move rapidly in a direction opposite to the train’s motion, but the distant objects (hill tops, the Moon, the stars etc.) seem to be stationary. (In fact, since you are aware that you are moving, these distant objects seem to move with you).

Answer 1

An imaginary line joining between the human eyes to a particular object is known as line of sight. When the person moves with fast speed the line of sight of close object changes rapidly. But the line of sight remains same for the distant object.

Similarly, when the passenger is looking outside through window of a fast moving train, the passenger observes that the nearby trees, houses etc seems to move rapidly because the line of sight between the passenger and the nearby things changes rapidly as the train moves very fast.

But when the passenger looks for the distant object like hill tops and the mountains, they seems to be stationary due to the line of sight remains same between the passenger and the distant object.