OT: Speed of light

[greg]

Erik Max Francis wrote:
> rocket motor performance (specific impulse) is measured in 
> seconds, as it's the ratio of the the thrust (force) to rate of fuel 
> usage (would be mass divided by time, but weight on Earth is used 
> instead of mass).

Which is particularly ironic, as you'd think that
rocket engineers, of all people, would be acutely
aware of the need to avoid confusing force and
mass!

-- 
Greg