XXth century_physics

Arthur Haas (1910)
2a
An electron moves on a circular orbit of radius r
within a uniformly positively charged sphere of
radius a. It experiences the force e2r/a r/a 3 . The
maximum energy of the electron moving in an
orbit of radius a equals the limiting frequency ν *
of the Balmer spectrum multiplied by h
hν * = e 2 /a
If ν * is also the frequency of the electron in this orbit, then from the
equilibrium of the Coulomb attraction e2 /a 2 and the centrifugal force
4π2ν *2 *2mea a an equation follows
h = 2π 2 |e|√√√√√√√√ mea which was found to be numerically satisfied
[Called a ”carnival joke” in Vienna]