One of the fundamental laws of the universe seems to be the law of Vibration. It says that almost everything moves, and nothing remains constant. Humans basically exist in a system of motion. When brain cells get activated, they set up a vibration in the body. Therefore, to move the hand, one needs to trigger brain cells to move the body, or the hand would not move. Brain-body coordination is always essential.
Vibration is indeed a mechanical process that causes oscillations around a point of equilibrium. The term originates from the Latin word, vibrationem (to shake or quiver). The oscillations can be regular, such as a pendulum's motion, or casual, such as rolling of tires on a gravel road. To illustrate further, the motion of a tuning spoon, the reed in a music instrument like piano, a mobile device, or the funnel of a loudspeaker are suitable for Vibration. Almost everything seems to vibrate through an external force.
