The World Grows

Part I: The Earth

The oldest known world map, Babylonian, 6th century BC. The text says this is a copy of a much older map, possibly 9th century BC. Babylon is at the center, surrounded by nine kingdoms, then the "Bitter River."

Reconstruction of the world map of Anaximander (c. 610-546 BC), based on much later texts.

Nineteenth-century reconstruction of the world map of Eratosthenes (c. 276-194 BC), showing the geographic knowledge of the Hellenistic Greeks.

World map drawn at Constantinople c. 1300 AD, based on the work of Ptolemy, c. 150 AD.

Reconstruction Al-Idrisi's Tabula Rogeriana, drawn for Roger of Sicily in 1154 AD. North is at the bottom.

Da Ming Hunyi Tu, the Amalgamated Map of the Ming Empire, c. 1400 AD. China makes up half of this world.

The Fra Mauro Map, c. 1456.

Cantino Planisphere, 1502: The two halves of the globe are united.

Hendrik Hondius, Nova Totius Terrarum Orbis Geographica ac Hydrographica Tabula, 1630

Our planet from space.

Part II: the Cosmos

Egyptian, from The Book of the Dead of Nestanebetisheru, c. 950 BC.

Cosmos of the ancient Hebrews, from here.

Page from the Codex Fejervary-Mayer illustrating a key principle of Maya cosmology, often called the Quincunx, that is, the Five: the Maya world was made up of four cardinal directions and a central point around which everything revolves. The altar in a temple represented that central point. Each direction had its own suite of deities, and there was also a god for each level of heaven and each level of the underworld; counts varied for how many levels there were but went as high as 13.

The geocentric cosmos of Aristotle and Ptolemy, as drawn in 1524.

The heliocentric cosmos, from Copernicus' De revolutionibus orbium coelestium.

In 1755, Immanuel Kant theorized that the visible stars were all in a cluster he dubbed an "island universe," and that the clouds known as nebulae were other island universes a vast distance away. In 1785 astronomer William Herschel drew this map of our island universe, the Milky Way.

By the late 1800s telescopes had grown powerful enough to resolve details in nearby galaxies; this is an 1899 photograph of the Andromeda Galaxy. But many astronomers remained unconvinced that these were really other galaxies as large as our own. In 1917, Heber Doust Curtis observed what he took to be a nova within the Great Andromeda Nebula. Searching through old photographs, he found 11 more novae. He calculated that these novae were about 10 magnitudes fainter than those within the Milky Way. As a result, he was able to come up with a distance estimate of 150,000 parsecs to Andromeda. In the 1920s Edwin Hubble used stars known as Cepheid Variables to refine this estimate to be about 275,000 parsecs, or 900,000 light years.

The Hubble Deep Field, to my mind the most important photograph ever taken. Based on Hubble data, astronomers calculated that there were 500 billion galaxies in the observable universe; that number has since been revised upward to around 2 trillion.