Caption: The Astronomer by Johannes Vermeer (1632--1675).

The model for the astronomer of the painting may have been scientist Antonie van Leeuwenhoek (1632--1723) who must have known Vermeer well since he was an executor of Vermeer's will.

The astronomer of the painting is examining a celestial globe which is a representation of the celestial sphere.

In Aristotelian cosmology, celestial sphere was a real physical object, the celestial sphere of the stars---and not just a sky mapping tool as in modern astronomy.

By Vermeer's time, belief in the celestial sphere of the stars was probably nearly gone.

Johannes Kepler (1571--1630) may have been the last important astronomer to have considered the celestial sphere of the stars a viable hypothesis (see Wikipedia: Celestial spheres: Renaissance).

Credit/Permission: Johannes Vermeer (1632--1675), circa 1668 (uploaded to Wikipedia by User:Jarekt?, 2011) / Public domain.
Image link: Wikipedia: File:Johannes Vermeer - The Astronomer - WGA24685.jpg.
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