I have often wondered how much of time is an objective reality versus a subjective experience, a mental construct. Is the fact that we remember events from only one direction in time (the “past”) and not the other (the “future”) a constraint based in reality or just a peculiar brain adaptation?
I recently read “The Order of Time” by Carlo Rovelli, a theoretical physicist specializing in quantum gravity. At the smallest scales of reality, he observes, modern physics demonstrates there is no space, time and matter but only interactions among fields. What we perceive as reality is just our heavily blurred (to use Rovelli’s word) perspective.
Since Einstein, it’s been fully proven that time has no inherent rate. It can move faster or slower depending on gravity and relative velocity. Atomic clocks in orbit, for example, tick faster than those on Earth.¹
But what about the direction of time? As Rovelli points out, the equations we’ve found governing fundamental reality have no time component. They hold true whether events sequence one way or the other. What does that tell us?
I guess I don’t know. I’m just a guy who read a fairly short book,
after all. For Rovelli, it’s among the reasons to believe the order of
time is localized, surely different in other parts of the universe
where different conditions prevail. And honestly, I’m not sure what
¹ For a recent, fun illustration, see “Einstein’s ‘Time Dilation’ Spread Age Gap for Astronaut Scott Kelly and His Twin”: www.space.com/33411-astronaut-scott-kelly-relativity-twin...