While there are some arrows of time, most equations in physics are time symetrical, giving some evidence that time can ripple backwards.
In other posts I often talk about time. In the normal view, time only flows from the past to the future, and we are living the repercussions of the past. But I have proposed, and given some evidence, that time is different and also sends ripples backwards causing pre-percussions — often felt as psychic or clairvoyance experiences — as well as sideways, causing cross-percussions from variant lives and timestreams (i.e. many-world interpretation).
Interestingly, physics actually holds that (almost) all events are time symmetrical: there is nothing in the laws of physics that would prevent a given interaction to happen backwards in time.
For example, you could easily reverse the collision of two billiard balls. Even a cup that falls off a table and shatters could “magically” reassemble itself if time could run backwards, there is nothing in the laws of physics itself that would technically prevent this as an impossibility.
Yet, we perceive time only running one way, from the past to the future.
Arrows of time
It is as if time “has an arrow” that it has to follow.
There are actually several candidates for such an arrow of time. The first one, clearly, is the psychcological arrow of time. This is clearly how we perceive time, moving from past to future, because we are embedded in this stream.
Yet, there are a couple of instances in physics that do also indicate an arrow of time, where time is not reversible.
The first one is the second law of thermodynamics, also called entropy, which states that a closed system always moves from order to chaos. This is why, under this law, a broken cup reassembling itself is exeedingly unlikely -- but still not statistically impossible!
One caveat here is “a closed system.” Clearly, an isolated experiment can be seen as a closed system, but at the grand scale, is the universe really closed? Today there are new theories that say, no, there are actually infinite universes, almost all hostile to life, but ours is special because here the physical variables happen to be setup in way so that life can develop. And possibly, these universes are all connected. So what does closed really mean? I have my doubts about entropy.
The other instance in physics that may indicate another arrow of time deals with the weak force at the nuclear level. Out of all atomic interactions we know, there is at least one that is not time-symmetrical: the decay of the k-meson takes longer in one direction than in the other ("Violation of CP symmetry"). This may also be a fundamental clue as to why during the creation of this universe, shortly after the big-bank, matter took precedence over anti-matter.
So on one hand, such an arrow of time shows why time seems to flow one way, or at least why we perceive it that way.
On the other hand, almost all other laws of physics show that time can also influence backwards!
Let me point out one prominent example. As stated, most physical equations can be solved be time-reversed, or even have two solutions. Most notably, the Maxwell equations, the de facto standard for describing the behavior of electromagnetic waves, have two solutions: one running forward in time – the so called retarded solution -- the other running backwards in time – the so called “advanced solution.” (The term retarded stems from the fact that a reaction is not instantaneous but takes a minimal amount of time).
Yet, the solution running backwards in time is simply discarded.
Thus, here is one of the most standard equations of physics, and it clearly shows how an electromagnetic wave can propagate backwards in time as well as towards the future!
And that has been the point I have been arguing all along: that past events influence future ones, but also that future events can influence the past, forming a temporal whole.
If we are to take the equations of physics literal, then it can indeed be so.
Namaste — I bow to you and the Divine in you.
Copyright © Hanns-Oskar Porr