However, relativity primarily completes the revolution that Newton started and is also highly deterministic as is much of classical physics. In the holistic viewpoint of relativity theory, concepts such as length, mass and time take on a much more nebulous aspect than they do in the apparently rigid reality of our everyday world. However, what relativity takes away with one hand, it gives back in the form of new and truly fundamental constants and concepts. The theory of relativity is traditionally broken into two parts, special and general relativity. Special relativity provides a framework for translating physical events and laws into forms appropriate for any inertial frame of reference.
General relativity addresses the problem of accelerated motion and gravity.
In particular, the newly formulated theory of electromagnetic waves required that light propagation occur in a medium. In a Newtonian Universe, there should be no difference in space or time regardless of where you are or how fast you are moving. In all places, a meter is a meter and a second is a second. And you should be able to travel as fast as you want, with enough acceleration. This would also test how light waves propagated since all waves must move through a medium.