Hello. What I know about the Van der Waals force is that it comes from an instantaneous electronic cloud flucutation of the netural atom. This instantaneous electric dipole of the atom attracts electrons in nearby neutral atoms so other electric dipoles are induced on those atoms. As a result, the atoms are attracting each other. This is what we call the Van der Waals force. My question is what is the origin of the instantanous electron cloud fluctuation of the atom? Is it from the uncertainty principle, saying the position and momentum of electrons are not simultaneously measured?