perpetual motion

nounMechanics.

the motion of a theoretical mechanism that, without any losses due to friction or other forms of dissipation of energy, would continue to operate indefinitely at the same rate without any external energy being applied to it.

Origin of perpetual motion

First recorded in 1585–95

Words Nearby perpetual motion

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use perpetual motion in a sentence

For instance, a counterfactual property imposed by the laws of physics is that it is impossible to build a perpetual motion machine.
Our Little Life Is Rounded with Possibility - Issue 102: Hidden Truths | Chiara Marletto | June 9, 2021 | Nautilus
In the current approach to physics, some laws already have this counterfactual structure — the conservation of energy, for example, is the statement that it is impossible to have a perpetual motion machine.
How to Rewrite the Laws of Physics in the Language of Impossibility | Amanda Gefter | April 29, 2021 | Quanta Magazine
For an artist in perpetual motion, that doesn’t sound like a stretch at all.
There’s no stopping Twyla Tharp, even as she approaches 80 | Peter Marks | March 18, 2021 | Washington Post
I want to always be in a state of perpetual motion: going somewhere, doing something.
Great Weekend Reads | Malcolm Jones, Matt Gallagher, Saul Austerlitz, Sharon Steel | September 11, 2011 | THE DAILY BEAST
It is a potent part of the Sarkozy brand: he is tireless and in perpetual motion.
Did Carla Wear Him Out? | Eric Pape | July 28, 2009 | THE DAILY BEAST

The poor soldier had one of those eccentric souls which need perpetual motion.
Juana | Honore de Balzac
I suppose I am growing old, for I begin to dislike perpetual motion.
Paul Patoff | F. Marion Crawford
Of course, such a doctrine cannot be true; it would amount to a perpetual motion!
Time and Tide | Robert S. (Robert Stawell) Ball
In fact, it is the old story illustrated, that perpetual motion is impossible.
Time and Tide | Robert S. (Robert Stawell) Ball
Or, perhaps, a still more lively illustration to some readers may be the idea of perpetual motion.
The Posthumous Works of Thomas De Quincey, Vol. 1 (2 vols) | Thomas De Quincey

British Dictionary definitions for perpetual motion

perpetual motion

noun

Also called: perpetual motion of the first kind motion of a hypothetical mechanism that continues indefinitely without any external source of energy. It is impossible in practice because of friction
Also called: perpetual motion of the second kind motion of a hypothetical mechanism that derives its energy from a source at a lower temperature. It is impossible in practice because of the second law of thermodynamics

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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