Until today, I never heard of a physics limerick.

Here's a good one from American Physical Society Sites:

On Liquor Production
by David M. Smith

A friend who's in liquor production
Owns a still of astounding construction.
The alcohol boils
Through old magnet coils;
She says that it's "proof by induction."

For more Physics Limericks:  http://www.aps.org/publications/apsnews/features/limericks/finalists.cfm