posted by Jon on .
what is not moving; fixed?
I do not understand your question. Whether or not something is moving or not moving depends upon the coordinate syatem you are using to measure the location.
If you are standing inside a moving elevator, you are fixed with respect to the elevator but moviong with respect to the building and earth.
Buildings are fixed with respect to the Earth but are rotating about its axis.
According to the theory of relativity, there is no such thing as absolute velocity.