# Confusion created by notation in E&M

1. Sep 8, 2012

### leroyjenkens

I just started an E&M class and right from the beginning the notation seems so confusing it has to have been done as a joke.
Trying to do a problem I run into about 10 different r's I have to keep track of.
Capital R
Lower case r
Lower case r prime
The r in spherical coordinates
The "squiggle" r (As this professor calls it. Never heard that before this class, but he talked about it like everyone knows. It's just a cursive r from what I can tell.)
"Squiggle" r hat
Normal r hat prime
"Squiggle" r with an arrow over it.
The normal r with an arrow over it
Normal r with an arrow over it prime

So when I see an equation with 3 or 4 different r's in it, my head just explodes. Why is it like this? And am I the only one who thinks this makes it confusing?

2. Sep 8, 2012

### ObsessiveMathsFreak

This is what happens when you restrict yourself to the latin Alphabet. Try using Greek and Cyrillic letters if you run out.

3. Sep 9, 2012

There is a weird fascination with symmetry and making letters look the same. Euler angles were introduced to me with $$\xi, \zeta, \eta$$ as indices. Integration by parts uses u and v, there is p and q for Lagrange mechanics. i and j for electrodynamics. {j,k,l} and {x,y,z} might not be so bad, but j and l are close in some handwriting as well as x and y. These things will never be reformed because we are still citing papers from 1910. The worst we had was in the discussion of collisions where I think r-prime-prime-tilda-hat was the vector of the second particle after the collision in center of mass coordinates.
I find it works extremely well when dealing with an unfamiliar notion to relabel each variable to something that makes sense to you, like $m_{electron}$ instead of $Z_0$ for example. Then rewrite all of the equations and work with them until you feel comfortable and translate back as required.