Willem Hendrik Keesom, Dutch physicist and academic (died 1956)

Willem Hendrik Keesom was a Dutch physicist who, in 1926, invented a method to freeze liquid helium. He also developed the first mathematical description of dipole–dipole interactions in 1921. Thus, dipole–dipole interactions are also known as Keesom interactions. He was previously a student of Heike Kamerlingh Onnes, who had discovered superconductivity.