(An excerpt from my book, Bonsai Coyote)
Physics, Per. 1
An Equal But Opposite Reaction
Newton’s Third Law of Motion states that to every action there is always an equal and opposite reaction. Newton’s third law is frequently misunderstood. For example, my mom forbade me from having my own car because of the one time I drove on the sidewalk. Some people would claim that this is an equal but opposite reaction, whereas I would claim that it is a gross overreaction, and Newton would sit down and put his head in his hands.
The main misinterpretation of Newton’s Third Law is a failure to understand that the action and reaction apply to different bodies. They are not equal but opposite forces acting on the same object, but rather, two objects exerting relatable forces on each other. Like the loose dog that forced me to turn the wheel which forced my tires onto the sidewalk and forced my mother to totally freak out.
Okay, not exactly. A better example would be the way a fish swims in a pond. The fish uses its fin to push water backwards, but all that does is move the water. It is the water pushing back on the fish that propels the fish forward.