What causes the sensation of passage of time?

Question

I know that time does not "flow" according to Einsteins general theory of relativity. Space and time are both integral fabric of the universe.

So, what is it that we perceive as the "passage of time"?

Why does it only seem to "flow" in one direction only?

Answer 1

It's caused by asymmetric awareness of past vs. future events (memories vs. predictions). The reason for this is that possibilities for the future are enormously greater than possibilities for past, based on what you know, due to the constant increase entropy of the universe. Entropy is a measure of possible states of a system. The effect on concisousness is the preception that the past is firm and "has happened", while the future is fuzzy and undetermined in comparison.

Answer 2

it is our perception only

Answer 3

Mr. Smooth-

This is no trivial question.  You may get some "feel" for it from Stephen Hawking's books.  The first ("Times Arrow") is not easy going.

The flow is, as has been said, perception.  

The "one way" is an entropy "thing".  Just as Humpty Dumpty will not reassemble himself and get back on that wall, neither will time "flow" backwards, which in some sense (and I'm not sure ANYONE can say why, exactly) would violate the thermodynamic assertion of increasing disorder.

You have picked a deep thing to ponder.  I have been "doing" physics for 30 years, and I am far from comfortable with time as an absolute apart from our human nervous systems.

I'm sorry I did not have a snappy answer that cleared everything up for you.

-Fred