How is the time not absolute

First look

With his three laws Newton created a very powerful building with which almost all "mechanical processes" could be understood in his time. He went from one absolute space out: "According to Newton, space was the sensorium Dei - the sense organ of God. Space existed forever and ever, given all bodies in majestic, godlike calm."(According to Sexl: What holds the world together, DVA-Verlag). Of course, Newton knew that location information must be based on a selected reference system. But all systems were in absolute space Length of a meter rule must be the same in all reference systems.

Also the time was one until 1905 absolute size. The time span between two events did not depend on the frame of reference from which the two events were viewed.

Towards the end of the 19th century, the speed of light was studied very precisely under various boundary conditions. Michelson and Moreley found that the speed of light in air or in a vacuum is independent of the chosen reference system. As a result, ideas about physical laws (e.g. the addition of speed) that were previously believed to be safe began to falter.

Michelson and Morley's experiment can be found on the following page. In 1905 Albert Einstein published his Special theory of relativity (which will later be replaced by the general theory of relativity has been expanded). From this theory it follows that there is no absolute space and no absolute time, but space and time are relative. The relativistic mechanics derived from its fundamental postulates differs significantly from Newtonian mechanics at high speeds. In the limiting case of very low speeds, however, the relativistic mechanics changes over to the Newtonian mechanics.

On the following basic knowledge pages, a few important consequences of Einstein's assumptions are addressed. A more precise derivation can be found in the chapter on special relativity.