What I mean is, is there a past, future and present? or just a NOW which changes?
I'm a computer programmer so the second alternative is from my programming experience. In this second alternative, I mean to ask, are we just in a stateful system like Conways game of life where there is just a NOW and then the system updates and then we are in a different NOW. In the conways game of life, there is never any past stored in the computer memory. In this case, the past is just an illusion from us recording events which have happened in our brain.
There is a distinct difference between the two, if there is actually a past, future and present then there is opportunity for things in the future to affect things in the past or time-travel might be possible. However in a stateful system like the game of life, then that really cannot happen.
Secondly, do any experiments confirm or deny either of these two options, is this already a decided problem in physics?