Stewart-Tolman effect

The Stewart-Tolman effect is a phenomenon in electrodynamics caused by the finite mass of electrons in conducting metal, or, more generally, the finite mass of charge carriers in an electrical conductor.

It is named after T. Dale Stewart and Richard C. Tolman, two American physicists who carried out their experimental work in the 1910s.cite journal
last=Tolman
first=Richard C.
authorlink= Richard C. Tolman
coauthors=T. Dale Stewart
year=1917
month=August
title=The electromotive force produced by the acceleration of metals |journal=Physics Review
volume=8
issue=2
pages=97–116
doi=10.1103/PhysRev.8.97] This eponym appears to be first used by Lev Landau. [cite book
last=Landau
first=L.D.
authorlink=Lev Landau
coauthors=E.M. Lifshitz and L.P. Pitaevskii
translators=J.B. Sykes, J.S. Bell and M.J. Kearsly
title=Electrodynamics of continuous media
edition=2nd ed.
series= Course of Theoretical Physics, vol.8
year=1984
publisher=Butterworth-Heinemann
location=Oxford, UK
isbn=0750626348
oclc=221962584]

In a conducting body undergoing accelerating motion, inertia causes the electrons in the body to "lag" behind the overall motion. In the case of linear acceleration, negative charge accumulates at the end of the body; while for rotation the negative charge accumulates at the outer rim. The accumulation of charges can be measured by a galvanometer.

This effect is proportional to the mass of the charge carriers. It is much more significant in electrolyte conductors than metals, because ions in the former are 10³-10⁴ times more massive than electrons in the latter.

Notes