classical mechanics

American  

noun

Physics.

1. the branch of mechanics that is based on Newton's laws of motion and that is applicable to systems that are so large that Planck's constant can be regarded as negligibly small (distinguished from quantum mechanics).

---

Etymology

Origin of classical mechanics

First recorded in 1930–35

Example Sentences

Until this hypothetical key to the mysteries puts a bow on string theory and reconciles quantum and classical mechanics, don’t bother.

From The Wall Street Journal • Jan. 9, 2026

From the perspective of classical mechanics, these boundary conditions and reaction constraints should not require energy, because they are treated as fixed and external.

From Science Daily • Jan. 6, 2026

Macroscopic objects made of very many atoms, on the other hand, normally obey classical mechanics: they cannot assume two contradictory states simultaneously.

From Scientific American • May 12, 2023

We once harnessed our knowledge of classical mechanics to build machines, to make factories, leading to the industrial revolution.

From Salon • Oct. 6, 2022

For example, the dinosaurs may have been exterminated by the impact of an asteroid whose orbit was completely determined by the laws of classical mechanics.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond