the sun rises in the east and sets in the west, which is caused by the rotation of the earth as you all know. but have you ever thought of the effect of the earth's rotation on man and can you imagine what would happen if the earth stopped rotating?

　　the radius of the earth is about 6,370 kilometres. it takes the earth 24 hours to rotate once. objects on the earth's equator move with the earth at a speed of 460 metres per second, and the air close to the earth's surface turns at the same speed. if the earth stopped rotating suddenly, the air would keep flowing eastward at a speed of 460 metres per second. the wind would be fourteen times as powerful as a hurricane. at the same time sea water would rush eastward at a speed of several hundred metres per second, which might do damages much greater than a seaquake would do. obviously, men could hardly stand such a catastrophe.

　　even if such a catastrophe would not happen, there would be a great temperature difference on the two hemispheres of the earth, and the four seasons of the year would no longer occur because a day and a night would be as long as a whole year instead of 24 hours. all this would greatly affect the life of human beings, imals and plants and that would cause worse results than anything imaginable.