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Isotropy

/aɪˈsɒtrəpi/noun

The property of having the same value or behaviour whichever direction is measured.

The Greek roots

ἴσος
ísos
equal
+
τρόπος
trópos
turn, direction

Literally: equal in every direction

The story of the word

Cosmology rests on it. The cosmic microwave background is isotropic to about one part in a hundred thousand, and that near-perfect sameness is the strongest evidence that the early universe was smooth. Materials science uses the opposite term constantly: wood is anisotropic, which is why it splits along the grain and not across it.

How it travelled
Ancient Greek → scientific coinage → English
First recorded
19th century

Same family

anisotropyisotopetropicheliotrope

In a sentence

Assume isotropy and the equations collapse to one variable.

The rock's magnetic response was far from isotropic.

Built on the same root

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