How do we know that time itself is a physical substance that can slow down? And how does time slowing down have a physical affect on clock rates at different elevations?
We can inductively infer from repeatable scientific observation that gravitational pull increases the closer objects get to the center of the earth. So it’s reasonable to infer that changes in gravitational pull from moving clocks closer or further away from earth’s center would at least be a plausible explanation of why clock rates change at different elevations.
What repeatable scientific observations are there from which we can inductively infer that time itself is a physical substance that can slow down and have physical effects on clock rates at different elevations? I’m not aware of any.
As far as I can tell, the only thing the repeated observations regarding time dilation tells us is that there is a lag of time in our measurements of those particular type of events that needs to be accounted for. And we know that our measurements are affected by our lack of ability to keep clocks in sync that are positioned at different elevations.
So how does it follow from those facts that time itself is a physical substance that can slow down and affect clock rates at different elevations? That seems like a mighty big logical leap to me. But that seems to be what you are suggesting.
What do the observations verify? They verify the equations of the theories, not the concepts. There aren’t any observations to verify the concepts. So explain to me why the concepts should get a free ride just because they happen to be useful as frameworks in formulating the equations in question? And explain to me how with empirical equivalence that opposing concepts can be equally true if concepts from successful theories are considered as true to reality?