Why is it that the vertical rays of sun fall only on the tropics?

Answer 1

The sun rays are never overhead at any point beyond the tropical zone.the word TROPIC means turning point.when the sun has reached its northernmost and southernmost most limits on June 21st (tropic of cancer) and 22 December (tropic of Capricorn) respectively,it appears to turn southward and northward

Answer 2

The reason is due to the tilted axis of the earth. The earth is tilted on its axis, with respect to the flat plane formed by earth's orbit. Sometimes the southern half is tilted towards the sun (max at southern mid-summer) and at other times the northern half is tilted towards the sun (max at northern mid-summer). And in between it shifts smoothly from one to the other.

The tilt is about 23 degrees off vertical. So any area between 23 degrees south and 23 degrees north will at some time of the year experience the sun directly overhead. In fact they experience it twice per year, once before mid-summer and then once after mid-summer.

Areas further south or north will never get the sun directly overhead. Its always somewhere lower between overhead and the horizon. Sometimes not even that. The worst case is the areas north of the arctic circle, or south of the antarctic circle, where in midwinter, the sun doesn't even rise.

Answer 3

Because only in the Tropic zone - between 23.5 degrees north to 23.5 degrees south - is the Sun ever directly overhead.

Answer 4

Becaseof its tilted axis.