Well, I don't even know what charge is?

It seems to me as the photon, we know it exist and we have descriptions for it.

We use it on a daily basis.

But I'm still not sure what the descriptions are talking about.

We can speak of electrons missing and entropy, like time, having an arrow wanting to 'equalize' the difference between those electrons missing and that other end where we have more of them.

"a charge is any generator of a continuous symmetry of the physical system under study.

When a physical system has a symmetry of some sort, Noether's theorem implies the existence of a conserved current. The thing that "flows" in the current is the "charge", the charge is the generator of the (local) symmetry group. This charge is sometimes called the Noether charge."

I like this description though as it is at my level:)

http://www.owlnet.rice.edu/~elec201/Book/basic_elec.htmlAnd if one have a burning interest then this one is good too:)

http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci840676,00.htmlAnd reading those two definitions you will know more than me:)

As my memory is like a sieve.

And I know that you don't need it Vern.

But I'm surprised over how easy it is for me to forget things I thought I knew.

I do it all the time:)

-----'loose'--quotations---

"Noether's theorem (also known as Noether's first theorem) states that any differentiable symmetry of the action of a physical system has a corresponding conservation law.

The action of a physical system is an integral of a so-called Lagrangian function, which is a function of the generalized coordinates and velocities of a dynamical system from which the equations of motion in Lagranges form can be derived.

From there the system's behavior can be determined by the principle of least action.

This seminal theorem was proven by Emmy Noether in 1915 and published in 1918-

And a Langrarian function is just a mathematical 'generalization' that summarizes the dynamics of the system using "any convenient variables" and "generalized coordinates" This makes it easy to incorporate constraints into a theory by defining coordinates which only describe states of the system which satisfy the constraints.

like you can do the same experiment in that jet-plane, as you can on the ground, not having to care that our earth moves at a constant speed of 30 km a second (I think:). So what it seem to state is that as long you are 'stationary' relative a uniformly moving frame of reference you won't notice any difference in your experiment, that is, if I got it right?