Sir Isaac Newton is the famous scientist known for his work on gravity. His groundbreaking publication, "Philosophiæ Naturalis Principia Mathematica," published in 1687, laid the foundations for classical mechanics and described the law of universal gravitation. Newton proposed that every particle of matter attracts every other particle with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. This revolutionary concept transformed our understanding of motion and laid the groundwork for much of modern physics, influencing countless scientific developments that followed.