I don't consider time to be a measurment, I consider time to be the thing we measure.
We age, everything (except Madonna) ages. That's time working. We just make up the measurement aspect of it.
How can you prove that everything ages? What is the effect of time on a diamond? does it become dull? Does it get...smaller? I dunno how does it change? It certainly doesn't experience any changes as far as I know. Does time stop for that diamond once it reaches the stage of being a diamond?
There is quite a lot in physics that shows that time is irreversible and that everything does indeed age.
Time is not absolute, which we know from the effects of relativity (the faster something moves, the more time speeds up from their point of view and slows down from the point of view of a stationary observer).
Time does appear to only move forward though, according to the second law of thermodynamics. There's a concept called entropy, which can be seen in more layman's terms as basically being a measure of how chaotic and variable the structure of something is, which the second law shows will only increase with time in the absence of energy being put in (and we also know that there is a fixed amount of energy in the universe so it cannot just be created from nothing). Let's take the example of:
1) a glass, and
2) an identical glass that has been shattered into pieces.
The glass is a stable structure, its molecules cannot really move around so the configuration is pretty much static. That would have low entropy. The shattered glass you can do anything with, you could separate the pieces and put them anywhere, in any configuration, so the entropy is higher. It is very easy to get from 1 to 2 with minimal energy expended (just drop it on the floor) but to get from 2 to 1 is impossible without melting down the glass and starting again from scratch, which takes a whole load of energy to do. This is essentially the science behind the fact that everything ages.
Now, onto the discussion of pre-determinism, some people seem to be struggling with the concept of it. Adami isn't necessitating that God is the one who pre-ordains everything, but if He knows everything that has happened and will happen then it has been pre-determined because there is no way that things could happen differently. In the Star Wars example, the viewer knows what is going to happen even though they had nothing to do with making the film, but it is the film's makers who pre-determine all the events throughout. Whether God is the one who determines everything that will happen or not is irrelevant, if he knows it then nothing can deviate from it, and thus it is pre-determined.