Time’s Arrow and Causality
Physicists sometimes tell us that the world is reversible and that there is a small but non-zero probability that your morning scrambled eggs could unscramble themselves, jump out of the pan, put themselves back together in their shells, etc. You bet!
On the other hand there is a well-observed arrow of time that contradicts reversibility in every well-tested case. It is claimed that this arrow of time is a mystery. Really?!?
Here’s a possible answer to the “arrow of time” problem and why we “can travel freely in three [spatial] dimensions, while only one direction” in the case of time.
Time is not like a spatial dimension. Rather it an ordering relation. Causality requires that things happen in a definite sequence for any observer. This definite sequence of events is the underlying basis of the observer’s concept and measurment of time and it has a very definite arrow, or “directionality”.
But bear in mind that while causality requires that all events follow a definite ordering for any given observer, different observers will sometimes measure elapsed time and even the ordering of events somewhat differently, as explained in special and general relativity. This does not remove the arrow of time for any observer.
Many of the imponderables of time are removed if we adopt this causality-based understanding of time, and its arrow.
Discrete Scale Relativity