píng​fāng​fǎn​bǐ​lǜ

inverse square law

  1. square
    The product of a number multiplied by itself; a square in mathematics; also called 二次幂 èr​cì​mì or 二次方 èr​cì​fāng
  2. inverse proportion
    (mathematics) a relationship between two quantities such that their product is constant, where one increases while the other decreases proportionally; inverse ratio
  3. noun
    law
    (bound form) law; rule; statute; regulation