Can anybody tell me what is Causal Solution

[walkinginwater]

Can anybody tell me what is " Causal Solution"

hi, everybody:
I am now reading some thing about field radiation. and it claims that the retarded potentials are the Causal solutions to the wave equations? http://www.ece.rutgers.edu/~orfanidi/ewa/ch13.pdf"

Can anybody explain what is the Causal solutions?

 

[mjsd]

your notes seem to have explained it pretty well... what is problem? "causal" means that events do not happen before the "trigger" that initiate the events. THat's why it the time argument, you need to evaluate the quantity at an eariler time.. because speed of light is not infinite, and it takes time for disturbances to reach the point of interest away from the source.

 

[walkinginwater]

your notes seem to have explained it pretty well... what is problem? "causal" means that events do not happen before the "trigger" that initiate the events.

I am sorry English is not my native language, but is the "Causal" has such kind meaning? Can you tell me an online English dictionary to check that?

 

[Mentz114]

In physics 'causal' can mean just that the future cannot affect the past. In other words an event may only be influenced by earlier events - not later events. Mathematically this give us the light cone causal structure.

 

[walkinginwater]

Thanks Mentz114, I got the answer I want!