Fill in the Blanks Universal Gravitation Law Fill in the BlanksOnline version Test your knowledge of the universal gravitation law by filling in the missing words in this physics-themed game. by Romina Tanzi 1 fundamental physics distance inversely square proportional principles force centers particle masses attracts particle Isaac Newton The universal law of gravitation states that every in the universe every other with a that is directly to the product of their and proportional to the of the between their . This law was formulated by Sir in 1687 and is one of the of .