What is space-time?

What is space-time or what is space-time continuum are mathematical representations that merge time and space as a one thing.  We consider our world as a three-dimensional and if we count time as a dimension then it becomes fourth dimension

If we look at multiple theories regarding the space-time we can easily see that time represented as a stable gateway, which is free of motion or an observer. However, if we put this theory in realistic context then it’s proven that it’s impossible to separate time from the existing three dimensional world. There are multiple elements comes into play when we calculate the time.

If you are looking a plane, flying over your head it will not feel that fast to you from your point of view but to people sitting inside the plane they won’t even realize that they are even moving but a person on watchtower certainly sense the incredible speed. This example might prove the point of passing time depend on the object’s velocity and observer and gravitational force.     

One thing to consider space-time just exist it does not evolve. This is a line from the past to future, which shows three-dimensional position at every point in time. The line does not change the time it exists as an enduring entity.  Because combining time and space we can easily locate any incident in history with help of time and space.