Griffiths Introduction to Elementary Particles · Problem 4.8

Bound States — David J. Griffiths

Physics — QFT · classical-electron-spin

Problem

Suppose we interpret the electron literally as a classical solid sphere of radius

r

, mass

m

, spinning with angular momentum

\frac{1}{2}\hbar

. What is the speed,

v

, of a point on its ``equator''? Experimentally, it is known that

r

is less than

10^{-16}

cm. What is the corresponding equatorial speed? What do you conclude from this?