Either the second law of motion, the second law of theromodynamics,the universal law of gravitation, or the law of inertia
Principia Mathematica explained the law of gravity and laws of motion in mathematical terms.
Newton's three laws of motion.
Philosophiae Naturalis Principia Mathematica
Isaac Newton published his Principia Mathematica in 1687 which included his laws of motion.
The Principia was created in 1898.
One of the key discoveries discussed in Principia by Isaac Newton is the law of universal gravitation, which describes the attraction between two objects with mass. Newton formulated this law to explain the motion of celestial bodies such as planets around the Sun.
Principia Ethica was created in 1903.
Principia Sardonica was created in 2004.
Principia Mathematica was created in 1913.
Principia Discordia was created in 1965.
Principia College was created in 1910.
Principia Cybernetica was created in 1989.