conservation of mass

American  

noun

Physics.

1. the principle that in any closed system subjected to no external forces, the mass is constant irrespective of its changes in form; the principle that matter cannot be created or destroyed.

---

conservation of mass British  

noun

1. the principle that the total mass of any isolated system is constant and is independent of any chemical and physical changes taking place within the system

---

conservation of mass Scientific  

1. A principle of classical physics stating that the total mass of a closed system is unchanged by interaction of its parts. The principle does not hold under Special Relativity, since mass and energy can be converted into one another.

---

Etymology

Origin of conservation of mass

First recorded in 1880–85

Example Sentences

The shape-shifting transfiguration spells in J. K. Rowling’s Harry Potter series, for instance, pose problems related to conservation of mass.

From Nature • Oct. 14, 2019

“Who is said to have formulated the law of conservation of mass and energy?”

From Slate • Aug. 6, 2018

I used to think being friends with an ex was a decent idea, like it established a certain level of maturity between two former partners while also confirming the law of conservation of mass.

From Salon • May 12, 2016

The divergence theorem has many uses in physics; in particular, the divergence theorem is used in the field of partial differential equations to derive equations modeling heat flow and conservation of mass.

From Textbooks • Mar. 30, 2016

This became known as the conservation of mass, and it was a revolutionary concept.

From "A Short History of Nearly Everything" by Bill Bryson