Word origin · etymology
A descriptive mathematical name: spherical refers to a sphere, geographic to Earth coordinates, and midpoint to a halfway point.
Sphere ultimately comes from Greek sphaira, ‘ball’; geography comes from Greek geōgraphia, describing the Earth's surface. The complete phrase specifies a construction rather than an ancient astrological entity.
Merriam-Webster: sphere — Word History ↗Merriam-Webster: geography — Word History ↗Merriam-Webster: midpoint ↗
How we know · epistemology
Declared geographic construction
This is one Davison location convention. Antipodal places have no unique shortest arc, and a polar midpoint has no unique longitude. The result is not an astrologically verified ideal location.
Connected concepts
Terms used in this explanation
These links connect subjects and terminology. They do not establish a shared historical origin.
Sources & provenance
Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.