The Three Laws of Motion
(1687) Changed our understanding of the universe by formulating three laws to describe the movement of objects. 1) An object in motion remains in motion unless an external force is applied to it. 2) The relationship between an object's mass (m), its acceleration (a) and the applied force (F) is F = ma. 3) For every action there is an equal and opposite reaction.
In his 1687 publication the ]PhilosophiÃ¦ Naturalis Principia Mathematica' 
