Dimensions are abstracts…they are just how we measure, calibrate and index things. They don’t look like anything, they only exists in our minds.
Space is three sub-dimensions of height, width, depth, or the xyz-axis – which measure/calibrate relative spatial position
You don’t see the dimension…height for instance is just the measurement.
And Time (the so-called 4th dimension) is the dimension of change…it’s how we calibrate and measure Change. Eg Motion (changing position) is measured as, say, miles PER HOUR. The per hour but is the calibration of the rate of change.
So we don’t see the fourth dimension, we don’t see any dimensions. They are abstract models. What we see are the the underlying realities being measured, indexed – that is position, and changing position, i.e. motion.
The ‘river of time’ is actually the river of change (the only real evidence of Time flowing is change). Time (in this context) is merely a collective noun.
And we all change…continually. So we change, with everything around us changing.
But we all change independently. Change is reference frame specific.
So the big collective flow (Time) and the indivudual events (from quarks decaying, atoms vibrating, life breathing, earth spinning, universe expanding…depending on reference frame) have their own specific ‘flow’.
The past changes to become the present which changes again to become the future.
This relationship is inherent in the core meaning of these words. So when people hypothesis about a different relationship, i’d say you need to go back and consider what past (has been) present (is) and future (will be) mean.
Not to forget that knowing the past relies on perfect memory or evidence, and knowing the future relies on perfect hypothesis and pattern understanding.
No. Spacetime is an abstract dimension. Space-time merely references the relative position and change of relative position (motion) of matter.
Causality is precisely the empirical evidence that proves what nonsense the block universe ‘theory’ is.
The past changes to become the present, which changes again to become the future.
The very essential, inherent meanings of these words, past (was) present (is) and future (will be), screams what a nonsense the block universe is.