True Motion Versus Local (Relative) Motion
2 minutes • 412 words
Table of contents
24. What is motion?
There is only local motion*. Local motion is the action by which a body migrates from one place to another.
Superphysics Note
A
to E
by going through points B
, C
, D
consecutively or successively. Whether the body is moving or not depends on viewspace (reference frame to Einstein)
Therefore, the same body changes place [from one perspective] and does not change place [from another perspective] at the same time.
Thus, it can also be said to be moving [from one perspective] and not moving [from another perspective] .
For example, one who sits in a ship departing from port thinks he is moving if he looks at the shores.
- But he is not moving if he looks at the ship itself which he is a part of.
We commonly think that there is:
- action in all motion
- no action in rest
The person thus seated is more properly said to be at rest than in motion, seeing he is not conscious* of being in action.
Superphysics Note
25. What is true motion?
True motion is THE TRANSLATION OF A WHOLE BODY (with its particles) FROM THE VICINITY OF THOSE BODIES AT REST THAT ARE IN IMMEDIATE CONTACT WITH IT, to the vicinity of other bodies.
The body might consist of many particles which have other motions within themselves.
True motion is a translation, not a force or action that transfers. Therefore, true motion is always in the moving object, not in the mover.
- This is because these two are not usually distinguished accurately.
Motion is merely a mode of the body just as:
- shape is the mode of a shaped thing
- rest is the mode of a resting thing.
It is not an inherent quality.