To understand Time, you have to first understand “What is Gravity?” Time is the fourth dimension that constitutes our space.
Although time flows forward, we perceive time relative to our position and movement in the space. This makes time a “variable” entity and therefore something that can’t be called fundamental (or foundational) to our Universe. And, that’s a big statement I just made. Think about that for a minute.
Arrow of time
The Arrow of Time is a concept developed by the British astronomer Arthur Eddington involving the “one-way direction” or “asymmetry” of time. This direction, according to Eddington, can be determined by studying the organization of atoms, molecules, and bodies in space.
Physical processes at the microscopic level are believed to be either entirely or mostly time-symmetric: if the direction of the time were to reverse, the theoretical statements that describe them would remain true. Yet at the macroscopic level, it often appears that this is not the case. There is an obvious direction (or flow) of time. But, why does the time behave differently at microscopic vs. macroscopic level? Does this mean, time is not an absolute entity!
If so, does that mean, we can travel forward and backward in time? Perhaps time travel is possible.