Einstein tells us time is what a clock measures, but clocks measure
units of flow. Clocks are convenient measuring sticks that allow
comparison of motion, change.
If you ask what a yardstick measures, I reply distance and show you
examples of distance, my height, the length of your car, etc.
Mass and energy can be stored and bits can be moved. Can time be
stored? If so in what way?
Consciousness requires comparisons to understand our world. If you
and I want to know how fast we can run, we can run a foot race and
note our comparative movement. I reach 100 meters while you go 80.
Your motion is 80% of mine. Decisions of who to send as a messenger
can use such a ratio to make decisions.
Clocks are so useful we forget they are tools to form comparisons,
ratios, to frame our understanding.
I think "time" is a convenience to provide comparisons, but suggest
there is only space of the now. If there is a recording mechanism
available, nows-past can be recorded and revisited..
What is "Now"? That is a mystery. Our senses deal in electro
magnetic waves and various nuclear forces which more and more seem
less and less substantial.
By the way, the smallest "now" might be Lorentz's distance. If only
he could have developed his transformation without light speed and
made it a ratio. Ratio of smallest distance to smallest energy unit?
Useful ratios such as circumference to density get by without time
units, horse races could be determined by ratios, man needs
comparisons to form understanding. Clocks are handy tools, but is
there a "time" dimension?