Question

I know this is a silly question, but I'm only asking this because I honestly can't seem to find a good definition of time that doesn't include another word that relies on the definition (or logical understanding rather) of time.

For example, in many dictionaries the definition of time is as follows:

Time is a measure in which events can be ordered from the past through the present into the future, and also the measure of durations of events and the intervals between them.

But the concept of 'past', 'present', and 'future' (mostly the first and last) rely heavily on time.

My best shot at a definition of time is this:

Time is the dimension on which the evolution of state of a system is allowed to occur.

Is this question senseless? Is the notion of time best left axiomatic? Do you know of a good/better definition of time? (The more concise the better)

Answer 1

Well , here is my experimentalist answer:

Time is a necessary parameter in order to describe observed changes in three dimensional space, dx/dt, dy/dt, dz/dt. If there were no observable changes in the (x,y,z) contour map of the world (including us as contours also) there would be no time parametrization needed.

These changes are an experimental fact and to start with the day and night clock was used to define the parameter. Clocks can be anything that consistently reproduces periodically the same (x,y,z) for a specific location/point.

This is classical time. Special relativity and even more General Relativity are a different story with much more sophisticated mathematical modeling.