The law of universal gravitation states that every particle of matter in the universe attracts every other with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

• 万有引力定律表明，宇宙中每种物质的粒子都对其他物质的粒子产生引力。这种引力与物质粒子质量的乘积成正比，与它们之间的距离的平方成反比。