Difference between speed and celerity?

1. Sep 8, 2006

mohlam12

okay, just a simple question...
what is the difference between speed and celerity?
thanks :)

2. Sep 8, 2006

Integral

Staff Emeritus
To the best of my knowledge "celerity" has no meaning in physics.

3. Sep 8, 2006

robphy

In relativity, celerity has been used to describe the quantity $$\frac{1}{\sqrt{1-v^2/c^2}}v$$, where $$v$$ is the velocity (whose magnitude is the speed).