In physics, gravity is the attraction between all matter and has a magnitude proportional to its mass and is inversely proportional to the square of the distance of the two objects. br br Gravity is one of the four basic forces of nature in a standardized model that is widely accepted in modern physics. The other three fundamental forces are electromagnetism, weak nuclear force, and strong nuclear force. Gravity is the weakest of these forces, but it can operate at long distances and is always attractive.