Short answers, pulled from the story.
Newton's Philosophiæ Naturalis Principia Mathematica was published on the 5th of July 1687. This book laid the foundation for classical mechanics by describing the motion of objects using geometric proofs rather than algebraic equations.
Leonhard Euler developed the equations of motion for rigid bodies in the 18th century. Euler lived from 1707 to 1783 and introduced the concept of angular momentum to describe how objects rotate and deform.
Joseph-Louis Lagrange published his grand opus Mécanique analytique in 1788. This work contained no diagrams and relied entirely on algebra and the principle of least action to describe systems by their kinetic and potential energy.
Clinton Davisson and Lester Germer conducted their experiment in 1927. Their work showed that electrons could diffract like waves when reflected from a nickel crystal, confirming the de Broglie hypothesis.
Albert Einstein published his special theory of relativity in 1905. This theory resolved contradictions regarding the speed of light by showing that time and space were relative to the observer's motion.