Atom center of mass, although strictly speaking these particles are believed to be point-like and cannot be said to be rotating. Spin is measured in units of the reduced Planck constant (ħ), with electrons, protons and neutrons all having spin ½ ħ, or "spin-½". In an atom, electrons in motion around the nucleus possess orbital angular momentum in addition to their spin, while the nucleus itself possesses angular momentum due to its nuclear spin. The magnetic field produced by an atom—its magnetic moment—is determined by these various forms of angular momentum, just as a rotating charged object classically produces a magnetic
Empire of the Atom bodily" from the plot of "I, Claudius". A genealogy chart of the ruling family of the Empire of Linn is included. Van Vogt based "Empire of the Atom" largely on the plot of "I, Claudius" by Robert Graves, putting it into a science-fictional setting. The work was originally presented as five novelettes published in "Astounding Science Fiction" between May 1946 and December 1947. Some time, a little over 10,000 years from now, a noblewoman gives birth to a deformed child, a consequence of having been accidentally exposed to radiation from one of the temples of the Atom Gods. The baby