4 ms·
If there are many objects moving in many directions, you won't be able to find a reference frame in which the mass of the system is equal to the sum of the rest
by whatshisface 2y ago
If there are many objects moving in many directions, you won't be able to find a reference frame in which the mass of the system is equal to the sum of the rest masses of the objects.
- Rhapso 2y agocorrect. This is not a contradiction. A reference frame is definitionally a point from which you would measure an "apartment mass". The rest mass isn't relevant to a reference frame where that mass isn't at rest. This is true at all scales.