In Aristotle’s physics there exists a prime mover that is in a state of absolute rest so that the position in space and time of everything else is understood relative to this place of absolute rest. Consequently, the reference frames of two observers are the same.

We still use this framework from the perspective of a trip or trajectory, measuring the distance traveled and travel time with length and time measures that are taken along for the ride. Such a one-dimensional perspective uses an absolute space and absolute time.

Galileo famously criticized Aristotle’s physics and said instead that the laws of physics

are the same for every observer moving with a constant speed along a straight line, called an inertial observer. Galileo regarded space as relative but left time absolute, which began the development of classical physics using three dimensions of relative space and one dimension of absolute time.

This partially changed with Einstein’s interpretation of the Lorentz transformation in the special theory of relativity (SR). This related both space and time but required an absolute framework of clocks to measure simultaneity. SR might be better called the theory of semi-relativity. It is still based on three dimensions of space and one of time.

If space is absolute but time is relative, one may develop an alternative with one dimension of space and three dimensions of time, as shown *here*. It remains to investigate fully relative space-time with three dimensions of space with three of time.

*Related*