Page "Quantum electrodynamics" Paragraph 41

Within the above framework physicists were then able to calculate to a high degree of accuracy some of the properties of electrons, such as the anomalous magnetic dipole moment.

However, as Feynman points out, it fails totally to explain why particles such as the electron have the masses they do.

" There is no theory that adequately explains these numbers.

We use the numbers in all our theories, but we don't understand them – what they are, or where they come from.

I believe that from a fundamental point of view, this is a very interesting and serious problem.