In physics, time is defined simply as change or the interval over which change occurs; it's impossible to perceive the passage of time without some form of change. where \Delta t is the change in ...In physics, time is defined simply as change or the interval over which change occurs; it's impossible to perceive the passage of time without some form of change. where \Delta t is the change in time or elapsed time, t_{\mathrm{f}} is the time at the end of the motion, and t_{0} is the time at the beginning of the motion. (As usual, the delta symbol, \Delta, means the change in the quantity that follows it.)
