positronium

American

[poz-i-troh-nee-uhm] / ˌpɒz ɪˈtroʊ ni əm /

noun

Physics.

a short-lived atomic system consisting of a positron and an electron bound together.

positronium British

/ ˌpɒzɪˈtrəʊnɪəm /

noun

physics a short-lived entity consisting of a positron and an electron bound together. It decays by annihilation to produce two or three photons

"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

Etymology

Origin of positronium

First recorded in 1945; positron + -ium; coined by Arthur E. Ruark (1899–1979), U.S. physicist

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

And the Cern group is not alone in their quest for frozen positronium.

From BBC • Feb. 22, 2024

The diagram below shows why positronium is so unique.

From BBC • Feb. 22, 2024

One of the first experiments frozen positronium could be used for is to see if its antimatter part follows Einstein's Theory of General Relativity in the same way as the matter part.

From BBC • Feb. 22, 2024

Up until now the coldest temperatures for positronium in a vacuum has been around 100C.

From BBC • Feb. 22, 2024

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023