permittivity permeability

einsteinian77

Could someone please tell me the most detailed and direct definition of permeability and permittivity. I know that they are porportionalities of some sort but what else could they be viewed as? Why is εμ = 1/c^2 ?

Tyger

"The Electromagnetic Interaction" which gives quite a good description. I highly reccomend it.

HallsofIvy

Check out

http://www.wikipedia.org/wiki/Permittivity

and

http://www.wikipedia.org/wiki/Permeability

jeff

Here's a tip. Often, when you've got some physical quantity that you don't understand, it helps to determine it's dimensional units. On the left hand side of the above expression, the dimensional units of a speed is involved. The next step is to identify what constants are available in the problem. For example, if the setting is electromagnitism in a vacuum, there's only one relevant constant with those dimensions, namely the speed of light.

This kind of dimensional analysis may not immediately clear everything up for you, but it can point you in the right direction.