Letter: So does nothing have a mass after all, then?

From Mel Austin, Perth, Western Australia

I am a keen reader of New Scientist but admit that I am no physicist and the apparent facts about the quantum world blow my mind. That said, may I ask a question?

I read that “As far as we can tell, electrons are points with precisely zero size” (9 September, p 38). Further on, I read that muons and tau particles are 207 and 3400 times the mass of an electron respectively.

Do I understand from this that something with zero size can still have a mass?