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
Sources & provenance
Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.