Our knowledge is not more than a drop in the pacific ocean. We do not understand (or even know) some of the simplest concept like how and gravity work, how energy is transferred, why does an electron jump. All we can do at present time is to consider the unexplained as axiom or postulate.
Every event in physics can be defined in terms of space and in terms of time. Space, time concept of universe was as primitive as Greeks, Hindu or Egyptian philosophy, but the proper working (or definition) was given by Newton.
Newton: According to him both time and space were absolute. They had frame which is independent of the observer. With this principle he was able to solve he Bucket problem (for more, click point no 4, below in reference links).
Leibniz: He strongly resented the idea of absolute space and time. According to him motion always existed with a reference frame and with respect to other object. Hence space and time are relative.
Mach: He also believed that space and time are relative and that accelerated motions depend on average mass distribution
Einstein: He gave an intermediate reasoning. He said that space and time when viewed distinctly are relative. But space-time when vied as single entity is absolute.
Here are reference link for a clear understanding.
2. EPR Paradox