Mass can't be everywhere. If mass were everywhere, then it would be impossible to turn over
in bed, move to the back of the bus, pass a slow car on the left, pour coffee into an empty cup,
take a deep breath, or sink a golf-ball into the hole (since there would be no hole).
Since mass is not everywhere, there are places where mass is not. To the places where mass
is not, we humans have given the name "space", because we are a lot more comfortable when
we label everything.