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Number & MeasureGreekEnglish

Asymmetry

/eɪˈsɪmɪtri/noun

Lack of balance or correspondence between two sides of something.

The Greek roots

ἀ-
a-
not, without
+
σύν
sýn
together, with
+
μέτρον
métron
measure

Literally: not measured together

The story of the word

συμμετρία means having a common measure, so ἀσυμμετρία was the Greek mathematicians' word for incommensurability: the diagonal of a square and its side cannot both be counted in the same unit. That discovery, credited to the Pythagoreans, wrecked the assumption that every magnitude is a ratio of whole numbers. English uses the word for lopsidedness instead, a sense that arrives in the 17th century, and particle physicists now use it for the tiny imbalance that left the universe with matter in it.

How it travelled
Ancient Greek → Latin → English
First recorded
17th century

The same roots elsewhere

Other languages reached for exactly the same Greek pieces.

Same family

symmetrymetregeometrydiameter

In a sentence

There is a slight asymmetry in every face, and photographs of mirrored halves look wrong.

Built on the same root

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