Is Newton's third law of motion still valid today? -- see additional details!?

Question

I mean, if our universe is expanding, is there another universe that is contracting because ours is expanding?

Answer 1

The third law is also valid in an expanding universe. Because it expands in all directions, for every particle that moves in a certain direction you will find another moving in the opposite direction and having an opposite momentum. This is enough.
However, you can interpret the law different....but it has to have a scientific basis.

Answer 2

It is unlikely that two universes would shove against each other as envisioned by Newton's third law. Two universes would likely collide like two masses of gas where particles from each cloud would mix and pass through each other. Stars tend to be light years apart with lots of room between them. All mass attracts (does not repel) other mass. Likely the combined mass of two universes could change the rate of contraction or expansion of the whole.

Answer 3

No your party isn't incorrect for Newton's third regulation of action. there is one action in touch: ball hitting the wall, and one reaction: wall causing the ball to bounce decrease back. The reaction is in incorrect way of action. besides the action rigidity and the reaction rigidity are co-linear, it really is, horizontal (assuming the wall is vertical).

Answer 4

well we can't say anything for sure.
but it is a phenemenon in science that we go by the statements that have been given previously.
since there is no proof about any other universe not contracting so we can assume that it is.
universe is a field of science in which we can't say any thing for certain.

Answer 5

To the best precision we can measure, the third law is valid.

Answer 6

This is a theory, its his idea. We actually have no way of verifying this information to be true. We don't know the limits so how can we be sure or the expansion?