Clockwise operation refers to the operation in the direction of clockwise movement, from top right to bottom, then to left, and back to top.
- Concept
- Running in the direction of clockwise movement
- Origin
- From its predecessor, the sundial.
- Purpose
- General screws, container covers
Mathematically, in Rectangular coordinate system The circle defined by the equations x=sint and y=cost is drawn clockwise as the value of t increases. In other words, when you keep moving to your right, you also move clockwise. Why the hour hand“ Clockwise ”Rotation is derived from its predecessor sundial 。 The hour hand first appeared in the Northern Hemisphere, and its function is similar to the "shadow pointer" projected on the ground by the sundial. The sun rises from the east and sets from the west. The shadow it casts on the sundial moves in the opposite direction, from west to east. So do the numbers representing time on the sundial. The numbers on the surface of modern clocks follow this arrangement. Generally, screws and container covers are loosened counterclockwise and tightened clockwise Right-handed rule 。 In the West, there is a short sentence "right tight, left loose" to help remember. (R H Daniel, 1980) But this is only applicable to the case of observing rotation from top to bottom. Another Memory method Is using the thumb; Hold up your left thumb. The curl direction of the other fingers represents the direction of tightening, and the right hand represents the direction of loosening. One of the reasons why the screw is tightened clockwise is that the right-handed person uses the supinator muscle of his hand to tighten the screw to Clockwise rotation That is the direction of handshaking. Generally speaking, the supinator is stronger than the pronator. 
