Space time is vastly known part of modern physics. It played a great role for understanding how gravity works. To understand it further more, I’ve generalized some parts to understand it and connect with time.
We know space and time are the 4 th dimensions in the universe. For instance if you want to meet someone let's say at a park, so you now have to give your friend the location to meet up but you also need time. You need to specify where and when to meet at that park so you need both direction and time. Similarly, for space you need both time and directions to locate something and that is how Einstein connected space and time at once to get a 4th dimension.
So now that we understand how space time is a 4 th dimension we can plot it in a graph and understand how time works in the space.
Below the graph you can see in y-axis there is universal time(T) and in x-axis there is space/direction.
If point A is stationary it could still feel time if it sits in chair or sleep there, the body would still feel time.So let's say point A has a wrist watch and measure which path between x and (x+5) takes more time to travel to point B. In classical physics we can say that straight path takes less time as it is the shortest distance but it is only in 3 dimensions. When we talk about 4 dimensions the longer the distance the slower the time. So, A will eventually found out that time is running fast if he took the curve (x+5) path.
In contrast, space time has its own metric which states that to reach the point A TO B the straight line is the longest line which takes longer time.
ARROW OF TIME
It is known that time travels only in a single direction yet and there are lots of queries about it. As time travels only in a single direction that is called arrow of time.
We can travel anywhere in space as a distance or direction but we can travel only in forward as a time. So, I think that time travel is possible and can flow in all directions but in our universe it is quite different may be in other universe it is possible to travel but if it's true then why is the other arrow of time locked? Why we can't go to anywhere in time like in space?
In other universe, those 3 locked arrow might be opened and things can travel anywhere at direction and time.
