From a Quora post September 2015
Is there no time?
The reactions to this question by both the scientific and general population are automatic and predictable in almost every post on the possibility of time not existing. Paraphrasing here: "Of course time exists. If time did not exist, everything would have at once" or "Our proven physics proves time exists because our equations require it to".
Why is this reaction so firm? Why do people defend the existence of time with such passion?
I have some guesses. Time exists for a few reasons:
1. As a convenience to assume away complexity in equations. Time does not act on anything (or at least I have not seen time in action). However, the correlation between clock time and an action or process is often misused as an actor of action (causation) in the sciences and in the general public. This is the case whenever change over time is used. The change is usually directly correlated with time as if time has something to do with causing the change. Again, time (to my knowledge) contains no energy and can cause no action. It simply makes equations less complex in most cases.
2. As a way to organize memory/what has been, based on clock/calendar time.
3. As a way to predict what may be based on the correlation of actions with clock/calendar time.
4. To communicate change in language. It is nearly impossible to relate in conversation or story telling without tense.
5. To make commitments in relationships based on events in the future.
There are perhaps many more reasons for time's existence as a tool for mankind. However, these reasons, though convenient for us, in no way prove that time is real. Only that the construct is very useful.
Here are my quick thoughts on the actual non-existence on time.
Now is all there is. Actions taken now create artifacts. Once brought into existence the artifacts are subject to more actions. Previous states of artifacts are recorded in various forms of memory (mentally, written, photos, light, geology, etc). These previous states recorded in memory are compared to current states or other previous states to give the standard change over time.
These forms of memory are interpreted by us as representing past, as tracking through time at a measurable pace based on the memory's existence. However, this is an interpretation provided by the existence of memory, not by the existence of actual, physical time. No memory, no time, only now.