This is a great review of the classical meanings of time given by many over the years. I am especially fond of McTaggart’s A, B, and C times, but have always been intrigued by his conclusion there was no coherent single answer. That always seemed odd...a philosopher without coherence?

Farr also mentions some physics, but he only just touches on relativity and quantum mechanics and he does not say anything about quantum phase at all. Farr states that the equations of relativity and quantum physics are fully reversible...but that is not true at all. Relativity represents all matter actions on irreversible determinate geodesics paths and those actions are not reversible in any sense and so there is never any causal confusion with relativity. In fact, the irreversible determinate paths of relativity are absolutely predictable to an unlimited classical precision. All precursors are prior to their outcomes and that is local cause and effect.

It is quantum action that shows a causal confusion of time in quantum reversibility. The quantum nature of matter action shows that quantum phase is very important but quantum phase does not seem to play any role in gravity relativity. Reconciling microscopic quantum phase with the macroscopic irreversible reality of gravity relativity provides a nice understanding of time as emergent, not axiomatic.

Time is not an infinitely divisible and continuous flow of gravity relativity, rather the notion of time emerges from a very large number of discrete and reversible quantum matter actions or changes. All quantum action is reversible because even though a precursor occurs for every outcome, the precursor and outcome exist together as a superposition for some very brief dephasing time. Therefore, one dimension of time emerges from a characteristic dephasing time that comes from the very slow and inexorable change in the universe. A very precise measure of dephasing is the time it takes for two atomic clocks to dephase from each other.

Once two quantum clocks dephase, the outcome then becomes part of our irreversible macroscopic gravity relativity and given a very large number of outcomes, the dephasing ensemble is effectively irreversible. However, the inescapable quantum result is even though all outcomes have precursors, not all outcomes have precisely knowable precursors. In the quantum world there are just more likely and never certain precursors and so there is a discrete quantum limit to the precision you can know about an outcome.

The second time dimension is in the very rapid ticks of atomic clocks, which all run in the same very slow direction of universe dephasing, the first time dimension. Despite the microscopic reversibility of each pulse of light in an atomic clock, the macroscopic nature of an atomic clock results in dephasing and therefore, from dephasing emerges an irreversible flow of events.

Note that time only has two dimensions because there are two kinds of things that happen; slow universe changes and fast atom changes. First of all, the universe changes very slowly as a single gravity event and second, atom changes are very fast and involve a very large number of quantum events. The two dimensions of time simply emerge from the two very different kinds of things that happen in the universe and therefore the flow of time does not exist otherwise....I still like McTaggart’s times though...

The second time dimension is in the very rapid ticks of atomic clocks, which all run in the same very slow direction of universe dephasing, the first time dimension. Despite the microscopic reversibility of each pulse of light in an atomic clock, the macroscopic nature of an atomic clock results in dephasing and therefore, from dephasing emerges an irreversible flow of events.

Note that time only has two dimensions because there are two kinds of things that happen; slow universe changes and fast atom changes. First of all, the universe changes very slowly as a single gravity event and second, atom changes are very fast and involve a very large number of quantum events. The two dimensions of time simply emerge from the two very different kinds of things that happen in the universe and therefore the flow of time does not exist otherwise....I still like McTaggart’s times though...