Number & MeasureGreek → English
Stereographic
/ˌstɛriəˈɡræfɪk/adjective
Describing the projection that maps a sphere onto a plane from a single point on the sphere, preserving angles.
The Greek roots
στερεός
stereós
solid, firm
γράφειν
gráphein
to write, to draw
Literally: “solid drawing”
The story of the word
Ptolemy described the construction in the second century without giving it a name, and every astrolabe ever built depends on it. The name arrived in 1613 from the Jesuit mathematician François d'Aguilon, who coined it alongside orthographic in his treatise on optics. Cartographers reach for it at the poles, where meridians come out as straight lines radiating from the centre and circles stay circles.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 17th century
Same family
stereometrystereoorthographicgeography
In a sentence
The stereographic projection turns the sphere into the plane plus one point at infinity.
Crystallographers plot face angles on a stereographic net.