Question

If everything in the universe is in motion then why there is a notion of rest?​

Answer 1

Answer:

Because everything in the universe is not in motion according to all objects.

Explanation:

We can say that something is in motion with respect to another thing. For example, 2 people are sitting in a train. For the 1st person, the 2nd person will appear to be at rest. But, if someone who is looking at the 2nd person through the train window, it will look like the 2nd person is in motion. It's according to the object in reference.

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