A one-metre globe shrinks Earth by forty million to one
Globes are spherical models of Earth, other worlds, or the sky that avoid the area distortion flat projections must accept. Latin globus means sphere. Strabo records the earliest known mention, describing a globe made by Crates of Mallus.
Because Earth's circumference is close to 40 million metres, a globe one metre around models the planet at 1:40 million; the popular one-foot-diameter version works out near 1:42 million. Raised-relief globes must cheat on height, since true-scale mountains would be invisible bumps. One 64-centimetre model makes its tallest peaks stand over 2.5 centimetres high, roughly 57 times too tall. Most globes carry parallels and meridians, many show country borders, and a surprising number include the analemma, a figure-eight tracing the Sun's apparent drift across the sky through a year. Stands are usually tilted 23.5 degrees, matching Earth's axis, which makes the seasons easy to picture.
Greek astronomers had shown the Earth was round by the 3rd century BC, and Crates of Mallus built the earliest known terrestrial globe in the mid-2nd century BC. None from antiquity survive. The oldest celestial globe rests on the shoulders of the Farnese Atlas, a 2nd-century AD Roman copy of a Hellenistic statue now in Naples. Globes of the whole Old World were made in the Islamic world, while Christian Europe produced none before the 15th century. China had no record of one until the Persian astronomer Jamal ad-Din brought a globe in 1276.
Martin Behaim, a German mapmaker and merchant, made the oldest surviving terrestrial globe in 1492 with the painter Georg Glockendon, calling it the Erdapfel. The Hunt–Lenox Globe, dating from around 1510, is believed to have given us the warning "here be dragons," and Taqi ad-Din built a strikingly modern-looking globe at his Constantinople observatory in the 1570s. Mughal scientists working for Jahangir made the first seamless celestial globe, and small Globus IMP devices guided Soviet and Russian spacecraft from 1961 until a digital map replaced them in 2001.
Traditional makers pasted paper gores, thin strips tapering to the poles, onto wooden balls; modern ones vacuum-mould printed plastic discs into two hemispheres. The Unisphere in New York, 37 metres wide, is the largest geographical globe, while Eartha in Maine, 12 metres across, is the largest that rotates.
Source: Globe
