Late 1500s: Galileo Galilei, known as the "father of science", was an Italian astronomer, physicist, mathematician, inventor and philosopher and was responsible for the discovery that heavy objects they do not fall to the ground as quickly as lighter objects. Galileo determined that “the acceleration of a falling body, the parabolic trajectory of a projectile, and the resistance of solids to fracture” (Swerdlow, 2011).3. 1687: Sir Isaac Newton publishes his book Philosophiæ Naturalis Principia Mathematica, often known by the simpler title Principa. The Principia included details on his law of motion and Newton's law of universal gravitation. Sir Newton took Galileo's theory that objects are attracted towards the center of the Earth and expanded the concept, demonstrating that the same gravitational force results in the orbit of planets in the solar system. “He used the Latin word gravitas (weight) for the force that would become known as gravity and defined the law of universal gravitation” (New World Encyclopedia,