RCSaunders wrote: ↑Wed May 29, 2019 1:56 am
Time is the relationship between the motion of entities. Just as length or distance and direction are the static relationship between entities, time is the relationship between entities when either their distance or direction from other entities changes (moves). Time, like length and direction, does not have any independent existense except as the relationship between entities that move.
Just as length and direction require some arbitrary unit which can be used to measure them, time requires some arbitrary unit of measure. Common ones are seconds, minutes, and hours. Just as there are no actual inches or feet, there are no actual seconds, minutes, and hours. All units of measure are human inventions.
Rulers and compasses are used to measure distance and direction, clocks are used to measure time. Rulers use a fixed length units and compasses used a fixed direction units. Since that which is being measured is change (in distance or direction) the device for that measurement (clock) has a fixed rate of change.
Time is not a substance or entity, it is a relationship. The relationships time is used to measure are real and exist, but only as relationships between physical entities. There is no time independent of those relationships.
So we don't measure any amount of space. We measure distances. We measure distances as you explain, by comparing objects
, at least in simple cases such as the distance between two nearby locations. However, we don't measure space because we don't know how to measure it. And that we don't measure space because we don't know how to measure it is not conclusive proof that space doesn't exist.
Same for time. Yes, I take your point that we don't measure time as such. Rather we compare processes to each other and use one as unit. So, in effect, we measure the rate of change and we call that a length of time, or the duration of the process.
Yet, again, that we only measure the rate of change doesn't prove conclusively that time doesn't exist. It just shows we talk of time, or indeed space, as if it exists even though we can't even measure it.
Relativity says time is relative. It doesn't say time doesn't exist. It says that absolute time doesn't exist, which is already something. Although, I don't think anyone knows whether even that is true.
Still, assuming as you do that time doesn't exist, what then makes two clocks stay (broadly) synchronised? I could ask a similar question about space, of course, but maybe answering the one about time will provide an answer to the one about space. So, do you know?