Linus Pauling: In 1929, Fritz London developed his quantum mechanical theory of Van der Waals attraction. Which is that as the electrons
move around the nucleus, in say the xenon atom, they are not equally distributed on the right and left side of the nucleus
so that the center of charge of the electrons coincides with the nucleus that carries the positive charge, but there are fluctuations
in the position of the center of charge so that there is an instantaneous electric dipole moment, producing them instantaneously
in an electric field. And that for a second xenon atom, too, there is an instantaneous electric dipole moment. And these two
instantaneous dipole moments interact with one another in a way that, in accordance with the fundamental principle of quantum
mechanics, leads to attraction.
This was very good, very interesting, it interested me very much in 1929 because this phenomenon of condensation, formation
of a liquid and then of a crystal, comes close to chemistry. At any rate, it's an important part of the world and I've tried
to understand the physical world all of my life.