Refer to this website's physics definitions for brief descriptions.
Causality is sometimes asserted to be a more precise term for describing what time actually is.
Two common ways of thinking about time are:
An abstract independent phenomenon which simply flows, within which all physical changes occur. Perhaps this is the most intuitive way of thinking about time – although time in this manner would have no substance of its own, and therefore it would be meaningless.
The change of physical state in one system relative to another system, e.g., 5 ticks of a clock vs another given number of physical changes, such as a person walking some distance during those 5 ticks – if there are no physical changes of any kind anywhere in the universe, then time simply doesn’t exist – i.e., time does not exist independently, in contrast to 1 above.
It is simply another way of referring to the laws of physics being responsible for one physical state logically causing another physical state.
The “Einsteinian block universe” concept describes all physical state across all time as existing in one instant, i.e., a tenseless existence of all physical reality in the entire universe, which we experience consciously, giving us the impression that time is flowing.
Therefore, the term “causality” is logically correct for 2 above, but not 1.
Random changes such as quantum fluctuations still represent time, simply because they are physical, i.e., time is simply change. Therefore, cause and effect are ultimately just the laws of physics (so to speak) – an abstract-dynamic-causal type of existence, hence the Einsteinian block universe referred to above, whereby the laws of physics are represented by the total state of all existence across all time.
In other words: “causality” is dynamic via its structural influence, but static in that it has no substance of its own – scientifically speaking it exists without reason, because a reason would require the existence of further abstract laws to explain the cause of (reason for) causality’s existence, and therefore this trend would have to continue, on, and on, and on.
A hypothetical universe which had no laws of physics (causality) would still contain time if changes still occurred, even if those changes were completely random.
In other words: time = the count of physical changes regardless of causality, or the count of logical sequential (corresponding) states of existence via the block universe idea.
And, although infinity is a misconception, we are forced to entertain the concept to enable us to identify various paradoxes – e.g., time must have a beginning, because it is impossible to count to the present from infinitely long ago.
As already touched upon above – reality existing via a block universe makes no difference to the paradoxical logic, because of “continuity”, i.e., all physical states must be connected (correspond) to their preceding state, and an infinitely long sequence of causal state would mean that any point in the sequence is cut-off from points infinitely previous to itself, i.e., a break in the logical chain of existence.
Philosophically, every time step is as remarkable as the 1st.
At some level we are forced to accept existence simply just is!
The sequences of causality (laws of physics) just exist, i.e., steps in time (so to speak) just exist.
Richard Feynman: at 14:54 explains magnetism... “you have to be in some framework that you allow something to be true”
We might wonder why time had a 1st moment? – but what is the actual reason subsequent steps occur? Not just the 1st.
Answering something like: “the second law of thermodynamics”, or “causality has been set in motion” – is simply not a plausible explanation, i.e., they are just descriptions that we have assigned to our observations of the universe in progress – not an actual explanation.
Zeno's Dichotomy Paradox (The Stadium): Zeno of Elea – Presented by: Professor Angie Hobbs ... also includes logical quantum movement examples: “The Arrow – A Clock for Zeno” and “Movement Logic of a Single Entity”.