What does dyne mean?
The dyne is a unit of force belonging to the centimetre-gram-second (CGS) system of measurement, which was widely used in science before the adoption of the modern SI system. One dyne is defined as the force required to accelerate a mass of one gram by one centimetre per second squared — a very small amount of force, equivalent to exactly one hundred-thousandth of a newton. The name derives from the Greek word 'dynamis', meaning power or force, reflecting its nineteenth-century origins in the study of mechanics. Although the dyne has been officially superseded by the newton, it still appears in older physics textbooks and in certain specialized contexts, most notably the measurement of surface tension, which was traditionally expressed in dynes per centimetre. For readers encountering historical scientific writing, familiarity with the dyne makes such passages immediately intelligible.
nounA dyne is the unit of force in the centimetre-gram-second (CGS) system, defined as the force required to accelerate a mass of one gram at a rate of one centimetre per second squared. It has largely been superseded by the newton in modern SI usage.
- A CGS unit of force equal to that which accelerates one gram at one centimetre per second squared; equal to 10⁻⁵ newtons.
"The instrument measured a surface tension of just a few dozen dynes per centimetre."
"One dyne is the force needed to give a one-gram mass an acceleration of one centimetre per second squared."
"Older textbooks often quoted surface tension in dynes per centimetre rather than in SI units."
Regular plural; commonly used when expressing measured values, e.g. in surface tension measurements.
"Water has a surface tension of about 72 dynes per centimetre at room temperature."
It takes ten million dynes to make a single newton — which is why physics classes quietly retired this tiny Victorian-era unit.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of dyne
The word 'dyne' was coined in the nineteenth century from the Greek 'dynamis', meaning force or power, the same root that gives us 'dynamic' and 'dynasty'. It entered English as part of the centimetre-gram-second system developed by British scientists, notably associated with the work of William Thomson and colleagues in the 1860s–70s. It shares its Greek root with words such as 'dynamic', 'dynamite' (itself coined later), and 'dynamics'.
How dyne is actually used
Dyne is a technical term found almost exclusively in older scientific literature, particularly pre-SI physics texts, and in some fields such as surface-tension measurement where dynes per centimetre persisted as traditional usage. It takes a regular plural (dynes) and is typically used with numerals or in compound expressions like 'per centimetre'.
Easily confused with dyne
The dyne is the small CGS unit of force (about 0.00001 newtons), whereas the newton is the much larger SI unit used in modern science.