What does it mean to have a charge?

[TheRingBarer]

I understand where is comes from and its effects on other things that have an electrostatic charge, but what does it mean to have a charge? Why do electrons repel other -ve (sub) atomic particles? It's really not something I find tangible. :)

 

[Whovian]

It's just a property of objects, as are mass, volume, and so on. It's just a little more ... hard to imagine than those.

If I remember correctly, we can derive Maxwell's equations from assuming another spatial dimension and taking charge to be the component of momentum in that dimension or something of the sort, but I think for now that's considered in the realm of other non-provable (or, rather, non-disprovable) theories such as string theory.

 

[ModusPwnd]

In the end, the best we can do with all basic properties is to define them by their interactions with other basic properties. "Why" is not a useful question, particularly not in physics. Usually when somebody asks "Why" in a science context the phenomenon is then described in terms of more basic phenomenon. Ex - Why is the sky blue? Because of refraction. Thats is fine, but continue that line of questioning and you will eventually hit a wall when you reach basic phenomenon. Once you get to basic phenomenon "Why" no longer makes sense to ask and "What" is the better way to ask the question.

If/when we do have an answer to "Why charge?" then that would imply we have more basic phenomena to appeal too. Basic phenomena which would in turn resist any question of "Why?".