Newton's Universal Time
Sir Isaac Newton was, for all intents and purposes, the inventor of modern physical theory. His ideas about motion and force for the most part still have great validity. There have been only corrections to his theory since it inception but nothing has ever replaced it. Newton thought of time as an ever flowing stream that was constant and immutable. In his theory time was always the same for any observer in any reference frame. This was the belief held by physicists in general for several hundred years. The mathematics used to describe how an event is observed in one inertial reference frame to another frame that is moving with some constant speed relative to the original is called the Galilean Transformation. For simplicity the two frames are usually aligned so that the direction of motion of the moving frame is along only one spatial axis. Also the frames must have their origins aligned at time equal to zero. The two frames are often referred to S, the stationary frame, and S' the frame moving at constant velocity v relative to S along the x-axis. The Transformation is then simply
As you can see there is no variation in time as measured by the moving or stationary observer. In Newton's universe we live in a 3- dimensional world where three dimensions are spatial, and we have complete freedom to move within them. Additionally, there is a parameter of time, but in this parameter we are confined to motion in only one direction and at one constant rate.