Created: 02 November 2016
Published: 02 November 2016
Last updated: 09 November 2020

Time is not a physical property

Time is an important issue in every day life and relativity. The definition of time can be found here. Time is a great measuring tool invented by humanity. Time helps humanity to predict and understand and explain all kinds of events. But time is NOT a physical property.

Remarkable is that time is defined in units of second. The SI definition of second is “the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom”.

So, the second is the duration of 9,192,631,770 periods of the radiation that is generated at the transition between the two hyperfine levels of the ground state of the cesium 133 atom.  This EM-radiation is in the micro wave band. Near the orange arrow.

Note that a caesium 133 atom cannot be nowhere. It has to be at some location, like inside a laboratory at our planet earth.

Performing the same time measurements at the caesium 133 atom at the centre of the Andromeda galaxy would probably yield another number of periods to fill the duration of 1 second at earth.

Is then time running faster/slower? Or is just the physical process running faster/slower?

Remember, using time in our calculations allows us to do amazing things, but time can never be part of a physical truth. Not at t=1 nor at t=2 nor at t=x. Period!