Originally Posted By: Bill S.

Would I be right in thinking you are saying that energy is an intrinsic property of matter which causes everything to be in constant motion?

If that is the case, when you talk of the Earth being at rest you must propose that some external forces are being applied to it to stop its inherent motion?

Apart from saying that a body appears, in or from your F of R, to be at rest relative to other bodies, how do you define “being at rest”?

Yes.
Yes, but no external force (however large it may be)can stop Earth.
The space is absolute. Since all the bodies are moving, it is impossible to observe a body at rest. That is our inability caused by the laws of physics. However, if the measured value of G is zero, then you can say that you are at rest (an indirect observation). All the moving bodies together constitute the universe, but the universe is not moving. The universe itself, like all other masses in it, tend to be nearly spherical; the centre of the universe is thus a point of reference (a point at rest) for all bodies, but the centre remains out of our view.