Conservation of momentum

[flano]

Who came up with the concept of this?

[jake-the-peg]

Newton

The law of conservation of momentum, which Newton derived as a corollary of his second and third laws, was the first conservation law to be discovered

see http://en.wikipedia.org/wiki/Newton's_laws_of_motion

[king_rocco]

yep, commonly referred to as "Newtonian Physics" and isnt always true either.

"energy cannot be created or destroyed..."

WRONG

 ;P