Motion (physics) Isaac Newton in his work "Philosophiæ Naturalis Principia Mathematica", first published on July 5, 1687. Newton's three laws are: Newton's three laws of motion were the first to accurately provide a mathematical model for understanding orbiting bodies in outer space. This explanation unified the motion of celestial bodies and motion of objects on earth. Classical mechanics was further enhanced by Albert Einstein's special relativity and general relativity. Special relativity is concerned with the motion of objects with a high velocity, approaching the speed of light; general relativity is employed to handle gravitational motion at a deeper level. Uniform Motion: When
Three Roads to Quantum Gravity Three Roads to Quantum Gravity Three Roads to Quantum Gravity: A New Understanding of Space, Time and the Universe is the second non-fiction book by American theoretical physicist Lee Smolin. The book was initially published on May 30, 2001 by Basic Books as a part of "Science Masters" series. Smolin discusses three potential approaches by which a unified theory of quantum gravity, arguably the foremost issue in theoretical physics, may be realized. Approaches discussed include string theory, M-theory, and Smolin's preferred approach, loop quantum gravity. Smolin suggests that these approaches may be approximations of a single, underlying theory. —"The Guardian"