Let's see how we can calculate the time "difference".
Because the photon is moving at the speed of light it has a 100 time dilation factor.
This, above all else, is the key to understanding special relativity.
The factor - c (speed of light) comes into the picture because the entire wolfenstein 3d mod maker theory is based on special relativity, which has constancy of light speed to be its central tenet.Read it again, think about it, then study the graph below.In fact our mass seems to increase at the same rate as time slows down (in a similar way to the graph seen earlier).This steady flow is so reliable that we fit our lives around.As brilliant as Newton was, he was, much to everyone's surprise, wrong.Note that at zero percent of the speed of light there is no time dilation at all.Special and general theory of relativity are two separate theories.The flow of time doesn't change very much but at speeds over about 75 of the speed of light the effect the house of the dead overkill game of time dilation is quite dramatic.It's easier, in this case, to do the latter.

Because we're only interested in the dilated time factor we can set the stationary time to.
For understanding the general theory of relativity, you will need some mathematical expertise in differential geometry and tensors.
One of the best introductions to special relativity is the book '.
For the sake of completeness I have included the relevant equation below but you can skip over it and move on to the graph below it if you prefer.Example 2: Solving the equation as a measure of time.You are able to read this now only because light, either emitted from your screen or reflected off a paper copy, is striking the back of your eyes and stimulating special cells which in turn send a "picture" to your brain.So at relatively slow speeds (our everyday speeds) time dilation is not a factor and Newton's Laws are still applicable.The basic idea is the following.For example, lets say we set off for a star 100 light years from Earth and our speed is 99 of the speed of light.Instead, because the distance has been dilated we will reach the star in only.1 years.How slow do clocks run?