Theophilosophical Physics: Ponderings on the Postulates of Special Relativity Pt. 2
In part one, I started a line of thought in which I realized that the speed of light, c, is also the speed of causality. I then ended by asking why causality needed a top speed and why that particular speed. I want to go deeper into these questions before I try to answer them and move on to my battle with time dilation and length contraction, which confused me greatly.
Thinking about causality brings me to qualify what I mean by the term. It may be an obvious point to make, but although time and causality are related, they are not equivalent. Causality is about cause and effect, time is about "duration", but more specifically, time is a "dimension". Time is not a requirement for causality. This may be a little confusing, but if you're not a hardened naturalist, meaning you believe in other causes other than material causes (which most people do), you know that, for example, one of the reasons we know a liquid is human blood is because it is red, human blood isn't blue. It is "effected" as human blood because (and note the "cause" in because) it is red, among other factors. The "cause" of it being blood is it's "essence" (nature) as a red fluid, along with other factors besides it's chemical composition, but also related to the chemical composition. Note that I mean that all red fluids are human blood, but that the red color of blood is a determining factor in it's existence as blood.
Aristotelians call this "Formal cause", and it is completely independent of time, although related to it. It doesn't even do to say that the cause and effect happen "instantaneously" as that still references time, it is independent of time altogether.
Therefore the causality I'm talking about here I would call "temporal causality", as it is causality that pertains to time, the "duration" of events and a dimension of the "Space-time continuum".
Time itself, as I mentioned earlier, is not just "duration" but a "dimension". Unlike Newtonian mechanics, you cannot think of time apart from space, the "spatial" relationship between all things cannot exist without their "temporal" relationship.
For Newton, the future didn't exist yet, the past has ceased to exist, only the present is "real" or "actual". However due to the "mechanistic" nature of Newton's theories, where all things are like the elements of a machine, everything was predetermined, it was assumed that given accurate enough "information", the future could be calculated. The theory of relativity doesn't necessarily remove determinism, it just transforms it.
In relativity, time is a dimension, it stretches from "past" to "future" like a line stretches from beginning to end (and it doesn't have to be a straight line), yet the line exists as a line all at once. The past and future already exist, but not in the same way as Newton's "universal time". It's still "deterministic", but it's not the closed mechanical universe of Newton.
This will inform my thoughts on this "temporal causality" and the need for a speed limit on it. It may also shed light on why this particular speed limit, but I'm starting to think that is above my pay grade, as it touches on the "anthropic principle".
I hope this clarifies some questions you might have. If not, the comments section is open. Thank you for reading :)