The hour hand first appeared in the northern hemisphere, and its function is similar to the "shadow pointer" projected by the sundial on the ground. During the day, the sun rises and sets in the west, and its shadow on the sundial is opposite to its running direction, from west to east, so the numbers representing time on the sundial are arranged in this way. The numbers on the surface of modern clocks follow this arrangement, and the direction of the hands on the clocks is clockwise.
Just as motion and stillness are relative, whether an object rotates clockwise or counterclockwise is also related to the observation angle. For example, when viewed from directly above the North Pole, the rotation of the earth is counterclockwise, and when viewed from directly above the South Pole, the rotation of the earth is clockwise.
In sports, such as table tennis, the server sends a ball that seems to rotate clockwise. On the opposite table, the ball seen by the other side also rotates clockwise, because both of them are standing directly above the ball to observe the rotation of the ball.
Extended data:
Clockwise operation follows the direction of clockwise movement, from the upper right direction down, then to the left, and then back to the top. Mathematically, the circle defined by equations x = sint and y = cost in rectangular coordinate system, with the increase of t value, the line segment represented is drawn clockwise. In other words, when you keep moving to the right, you are also moving clockwise.
Generally, screws and container covers are unscrewed counterclockwise and tightened clockwise, which conforms to the right-hand rule. One of the reasons for tightening the screw clockwise is that right-handed people use the supinator of their hands to rotate the screw clockwise, that is, the direction of shaking hands. Generally speaking, the supinator is stronger than the pronator thigh.