The unit of kinematic viscosity in the centimeter-gram-second system. Symbol, St (formerly S). A fluid with a dynamic viscosity of 1 poise and a density of 1 gram per cubic centimeter has a kinematic viscosity of 1 stokes. In SI units, 1 stokes = 1 centimeter squared per second.

According to the current national standard in the United States¹, the stokes is not to be used. Square centimeters per second should be used instead.

portrait of Stokes

The stokes is named for the British physicist, Sir George Gabriel Stokes (1819 – 1903), an early investigator of viscosity² and the founder of the Cambridge school of mathematical physicists.

1. IEEE/ASTM SI 10™-2002.
American National Standard for Use of the International System of Units (SI): The Modern Metric System.
New York: IEEE, 30 December 2002.

See Section 3.3.3.

2. For example,
On the theories of the internal friction of fluids in motion and of the equilibrium and motion of elastic solids.
Proceedings of the Cambridge Philosophical Society. Mathematical and physical sciences.. 1840's

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