1911: Weiss magneton - The book of science

Weiss magneton
No theoretical argument
Units of the indefinite
Commentary

Weiss magneton

Pierre Weiss derived a unit
of magnetic field strength
by comparing the magnetic properties
of nickel and iron.

No theoretical argument

Theorists could not justify the Weiss magneton
with their early quantum theory.
Weiss’s idea of an elementary magnet
originated with Walther Ritz,
who said atoms might contain
chains of tiny rods,
some having no magnetization,
and some acting as tiny bar magnets.

Units of the indefinite

I’ll explain everything in a moment.
There’s no time for unnecessary uncertainty.
Sufficient degrees of ineffable confidence
will immediately set the matter to rest.
If the shoe fits, then its size is right.

The Weiss magneton was based on a model of the atom that preceded the work of Ernest Rutherford and Niels Bohr. Weiss knew that something in some kinds of atoms was responsible for creating magnetic fields, but he didn’t know what it was. Theoretical physicists complained that it ought to be related to the Planck constant, which is the quantum unit of action, but the Weiss magneton could not be related to the Planck constant.