Sir Isaac Newton publishes his three laws of motion:

1) Every body continues in a state of rest or uniform motion in a straight line unless acted upon by an external impressed force.

2) The rate of change of momentum is proportional to the impressed force and takes place in the direction of the force.

3) Action and reaction are equal and opposite, i.e. when two bodies interact the force exerted by the first body on the second body is equal and opposite to the force exerted by the second body on the first.