Stewart-Tolman effect
Encyclopedia
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. This eponym
appears to be first used by Lev Landau
.
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.
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of electrons in conducting metal, or, more generally, the finite mass of charge carriers in an electrical conductor
Electrical conductor
In physics and electrical engineering, a conductor is a material which contains movable electric charges. In metallic conductors such as copper or aluminum, the movable charged particles are electrons...
.
It is named after T. Dale Stewart
Thomas Dale Stewart (physicist)
Thomas Dale Stewart was an American chemist.He was born at Sumner, Washington, and received his Ph.D. degree in chemistry from University of California at Berkeley in 1916...
and Richard C. Tolman
Richard C. Tolman
Richard Chace Tolman was an American mathematical physicist and physical chemist who was an authority on statistical mechanics. He also made important contributions to theoretical cosmology in the years soon after Einstein's discovery of general relativity...
, two American physicists who carried out their experimental work in the 1910s. This eponym
Eponym
An eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
appears to be first used by Lev Landau
Lev Landau
Lev Davidovich Landau was a prominent Soviet physicist who made fundamental contributions to many areas of theoretical physics...
.
In a conducting body undergoing accelerating motion
Acceleration
In physics, acceleration is the rate of change of velocity with time. In one dimension, acceleration is the rate at which something speeds up or slows down. However, since velocity is a vector, acceleration describes the rate of change of both the magnitude and the direction of velocity. ...
, 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
Galvanometer
A galvanometer is a type of ammeter: an instrument for detecting and measuring electric current. It is an analog electromechanical transducer that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field. .Galvanometers were...
.
This effect is proportional to the mass of the charge carriers. It is much more significant in electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
conductors than metals, because ions in the former are 103-104 times more massive than electrons in the latter.