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Astrophysics

/ˌæstroʊˈfɪzɪks/noun

The physics of stars and other celestial bodies.

The Greek roots

ἄστρον
ástron
star
+
φύσις
phýsis
nature

Literally: star nature

The story of the word

The word arrived in the late nineteenth century because the subject did. Once the spectroscope showed that the same elements burn in the Sun as in a laboratory flame, stars stopped being points to be mapped and became objects to be explained. Astronomy names the stars; astrophysics asks what they are made of and why they shine.

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

Same family

astronomyphysicsastrologydisaster

In a sentence

She switched from pure maths to astrophysics after one summer at the observatory.

Built on the same root

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