Why would it be relative? What makes you think it might be?

It was just a thought that occurred to me when I was thinking about time travel. It got me thinking that is things in motion are relative then why not maybe things that have different masses for example.

It was just a thought that occurred to me when I was thinking about time travel. It got me thinking that if things in motion have different perceived timeframes then why not maybe things that (even while stationary) perceive a different cause and effect, a bit like quantum mechanics where observation is different depending on other factors (I'm not a QM expert).

Here's a simple experiment, naiveman.

Have your friend stand about 300 meters from you. Then have him phone you and with the phones open have him yell as loud as he can. You can easily notice the difference and the time lag: that you hear his yell on the phone far earlier than you hear him by air. You can easily notice two different time frames and also assume the third small fraction of when the sound goes through the communication system to your phone. Speed of sound in the air is pretty slow. (For example, notice how few movies get this right with lightning or with explosions happening farther away)

Now, does this make causality different? Because the causality is that your friend agreed to do the experiment and yelled, making a sound that you then heard twice.

Do notice this in physics:

In classical physics, an effect cannot occur before its cause. In Einstein's theory of special relativity, causality means that an effect can not occur from a cause that is not in the back (past) light cone of that event. Similarly, a cause cannot have an effect outside its front (future) light cone. These restrictions are consistent with the grounded belief (or assumption) that causal influences cannot travel faster than the speed of light and/or backwards in time.

Here it is important to understand what specific idea is behind this thinking: that it is about physical effects. Yet the thing is that we can understand that when look at the night sky we are seeing "past history" of stars and galaxies in the sky.

Ok, but causality isnt the sort of thing that can be relative. Your question only makes sense if you offer some reason for us to treat causality as something that could be relative, otherwise the answer is just “no, because causality is not relative”.

well there wasn't really much thinking behind jt as it was just a quick though. I guess I was just wondering that basically instead of causality being objective (A=B) it could be thought of as also subjective in a way or relative in this case.

Ok.