The law itself states that each particle in the universe attracts another particle with a force directly [[proportion|proportional]] to the product of their masses and inversely proportional to the [[exponentiation|square]] of the distance between them<ref>Serway and Beichner, Physics for Scientists and Engineers, Fifth Edition</ref>, or: | The law itself states that each particle in the universe attracts another particle with a force directly [[proportion|proportional]] to the product of their masses and inversely proportional to the [[exponentiation|square]] of the distance between them<ref>Serway and Beichner, Physics for Scientists and Engineers, Fifth Edition</ref>, or: |