In Galilean relativity if I walk eastward towards a tree with uniform velocity this is equivalent to saying the tree is moving westward towards me with the same uniform velocity. As a fundamental proposition of modern physics this is eminently useful but it is also absurd. It is useful if what is deemed important about the motion of bodies is the possibility of past or future collisions (In the absence of such obvious possibilities the notion of a force was devised to explain changes in uniform velocity). It is absurd because it is detached from what we actually know about the world on a personal level. The tree is at rest because it is rooted in the Earth and I am moving towards it. I cannot get the tree and the Earth to move towards me by simply declaring I am at rest. There has to be a property of matter that expresses this non-relative quality of "rootedness" which has been ignored by physics since the 1600's.
Harry
