Question

The two postulates of special relativity sometimes lead us into conclusions that do not make sense with our classical intuitions; these cases are called "paradoxes." In many resolutions of these paradoxes, one key result in special relativity, "relativity of simultaneity" plays a key role. Explain what "relativity of simultaneity is and describe one situation where this understanding helps resolve a special relativity paradox.

Answer 1

Relativity of simultaneity:

This concept suggests that even when two separated occurences or events in space occur simultaneously, they appear to an observer simultanous or unsimulaneous depending upon reference frame of the observer who is visualizing both incidents/events.

One Situation to resolve paradox:

(a) Now, consider a situation, where you are standing on a platform in the mid at equal distance from two light sources which are opposite to you on both sides and emitting light pulses simultaneously or at same time towards you.

(b) But you are not aware that light sources are at equal distances and they are emitting light at same time towards you.

(b) For better visualization, this is the case:

Light source 1 Light source 2

(c) So, when light pulses will hit you at same time from both direction, you will realise that both light sources are emitting light at same time and are at same distance.

(d) Now, suppose, the platform starts moving towards Your Right side. Even in this situation light pulses will hit you from both direction at same time.

(e) But in above condition you may infer that:

Since platform is moving towards right, but still light is reaching to me at same time from both directions, it means Light source 2 is emitting light at me earlier than light source 1. So, as a consequence both light pulses are reaching to me at same time although I am moving towards light source 1.

But logically it was not right. So this is a paradox; means when reference frame of observer started to play things became different for observer.

Such paradoxes are easily interpreted and resolved with the help of "Relativity of Simultaneity" concept.

THANK YOU!!!