Question

To whom does the elapsed time for a process seem to be longer, an observer moving relative to the process or an observer moving with the process? Which observer measures proper time?

Short answer

The proper time is said to be the time measured by an observer at rest which is relative to the process being observed.

Step-by-step solution

Define Special Relativity

The special theory of relativity, sometimes known as special relativity, is a physical theory that describes how space and time interact. Theoretically, this is known as STR theory.

Explanation

An observer at rest measures the right time in relation to the process being seen. Furthermore, the time dilation notion uses the equation\({\rm{\Delta t = \gamma \Delta }}{{\rm{t}}_{\rm{0}}}\)to connect the appropriate time denoted as\({{\rm{t}}_{\rm{0}}}\)to the time measured by an observer in another moving frame.

We have the value: \({\rm{\gamma = }}\frac{{\rm{1}}}{{\sqrt {{\rm{1 - }}\frac{{{{\rm{v}}^{\rm{2}}}}}{{{{\rm{c}}^{\rm{2}}}}}} }} \ge {\rm{1}}\).

The conclusion is that for the observer who is not moving with the process, the elapsed time of the process appears to be longer.

Therefore, the correct time is defined as the time recorded by a stationary observer in relation to the process under observation.