# What does this symbol stand for?

1. Dec 5, 2004

### Lorax

4πε0r^2

Thats 4pi (backwards 3 0) R squared.

I forget what the backwards 3 o stands for can someone help me out

2. Dec 5, 2004

### Hurkyl

Staff Emeritus
$\epsilon_0$? Permeability of free space. (Or is it permittivity? I always forget which)

3. Dec 5, 2004

### Gokul43201

Staff Emeritus
$\epsilon _0$ is known as the permittivity of free space and is equal to about $8.85~ *~ 10^{-12}~~ F/m$

It is a proportionality constant relating the electric displacement vector to the field strength.

OR, it can be thought of as a constant connecting electric field (or force) to the values of charge and distance.

Last edited: Dec 5, 2004