Armillary Spheres: What They Got Wrong

Armillary spheres were used to study the sky and the celestial coordinate system

Armillary sphere
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An armillary sphere is a miniature representation of celestial objects in the sky, depicted as a series of rings centered around a globe. Armillary spheres have a long history.

Early History of the Armillary Sphere

Some sources credit Greek philosopher Anaximander of Miletus (611-547 B. C.) with inventing the armillary sphere, others credit Greek astronomer Hipparchus (190-120 BC), and some credit the Chinese.

Armillary spheres first appeared in China during the Han Dynasty (206 B.C.-220 A.D.). One early Chinese armillary sphere can be traced to Zhang Heng, an astronomer in the Eastern Han Dynasty (25 A.D.-220 A.D.).

The exact origin of armillary spheres cannot be confirmed. However, during the Middle Ages armillary spheres became widespread and increased in sophistication.

Armillary Spheres in Germany

The earliest surviving globes were produced in Germany. Some were made by German map-maker Martin Behaim of Nuremberg in 1492.

    Another early maker of armillary spheres was Caspar Vopel (1511-1561), a German mathematician and geographer. Vopel made a small manuscript terrestrial globe housed within a series of eleven interlocking armillary rings produced in 1543. 

    What Armillary Spheres Got Wrong

    By moving the armillary rings, you could theoretically demonstrate how the stars and other celestial objects moved in the sky.

    However, these armillary spheres reflected early misconceptions of astronomy. The spheres depicted the Earth at the center of the universe, with interlocking rings illustrating the circles of the sun, moon, known planets, and important stars (as well as the signs of the zodiac). This makes them a model of the inaccurate Ptolemaic, or earth-centered, cosmic system (as opposed to the way things actually work, by the Copernican System, with the sun as the center of the solar system.) Armillary spheres often got geography wrong, too—Caspar Vopel's sphere, for instance, depicts North America and Asia as one land mass, a common misconception of the time.