This is true of time as well. The way to understand time is by light. Light can't move faster than time. This is the way we know time has a boundary to it. It is important to remember that time is not light and light is not time.
Time is an awesome force that allows energy to exist in the state of matter.
The boundary of time can be understood as the speed of light. Volatility or speed if you will is what allows energy to exist in the state of matter. A time constant for matter of the universe is what makes it so stable, and gives it it's harmony. In this theory it says everything is moving away from everything else. By using the change in the wavelengths of light that hit us, they use this as the basis for the big bang theory.