Beside the idea of space-time as the theater or "stage" of the universe there is an alternative
view where time is understood as change of matter in space: "In Newtonian physics,
physical time is an independent quantity (absolute time), running uniformly throughout
the entire cosmic space (absolute space). In the Theory of Relativity, time is no more an
independent physical quantity - it is linked with space in four-dimensional space-time.
Here physical time is understood as a stream of irreversible change that runs through
physical space. The important point is: Change does not "happen" in physical time --
change itself is physical time. This is a different and more correct perspective than the
conventional view in physics, in which space-time is the theater or "stage" on which
change happens". (1)
Time is only a "by-product " of matter that is continuously changing (moving) in physical
space. In physical space itself time as understood by Einstein does not exist. According
to this understanding gravitational force can be attributed to the physical space and not
to the "space-time". The idea of "roundness of space-time" is replaced with the idea of
"roundness of space". The "areas" of bigger roundness attract each other. Physical
space itself is carrying gravitational force. Probably there are no gravitational waves
between stellar objects.