Number & MeasureGreek → English
Symmetry
/ˈsɪmɪtri/noun
The property of being unchanged when a figure or system is reflected, rotated or otherwise transformed.
The Greek roots
σύν
sýn
with, together
μέτρον
métron
measure
Literally: “measured together”
The story of the word
Συμμετρία meant commensurability: two lengths were symmetrical when a single unit measured both without remainder. From that came the builder's sense of due proportion, which is what Vitruvius passed to the Renaissance and what English took in the 1560s. The modern meaning, invariance under a transformation, is a nineteenth-century mathematical hardening of the old idea, and it now runs the deepest parts of physics through Noether's theorem.
- How it travelled
- Ancient Greek → Latin → English
- First recorded
- 1560s
The same roots elsewhere
Other languages reached for exactly the same Greek pieces.
Same family
metricgeometrydiameterasymmetry
In a sentence
The facade has a symmetry that the interior completely ignores.