We never travel in space without time passing.

What is behind the principle that the faster we go,
 the more slowly we experience time?
 It begins with understanding that the speed of any object in the universe can be seen as a function of traveling in both space and time.
 We never travel in space without time passing. 
Physics has determined that the faster we go in space, the slower we
go in time.
 As we travel at normal speeds, that is not apparent to us. 
But as objects accelerate and approach the speed of light, it becomes apparent that speed in time slows down the more speed in space increases
—the maximum point being the speed of light.
In our universe, nothing can exceed the speed of light in space. 
And the slower we travel relative to the speed of light,
 the faster time passes. 
So for human beings,
time passes very quickly relative to light 
because we move very slowly in space in comparison to light. 
Thus the combination of speed in space 
 in time 
always equals 
Speed of light.