Symbol Gallery

Nebra sky disk, Bronze Age

Nebra sky disk. Artwork of a Bronze Age artefact known as the Nebra sky disk. Made of bronze and inlaid with gold, this object is around 30 centimetres across. It was found in Germany and is thought to date to around 1600 BC. The gold symbols are thought to represent the Sun (left), a Crescent Moon (right), and the stars (dots). The two arcs at left and right represent the angles between the rising of the Sun at the solstices, and the arc at bottom may represent the barge of the Sun, or the Milky Way. The disc is now kept in the Saxony-Anhalt State Museum for Prehistory, Germany

© JOSE ANTONIO PE'AS/SCIENCE PHOTO LIBRARY

Standard periodic table, element types

Standard periodic table, colour-coded for element types. The periodic table shows the chemical elements ordered by atomic number (number of protons in the nucleus), but arranged in rows (periods) so that elements with similar chemistry occur in the same vertical column (group). Here, blocks of elements with similar chemical properties are shown by the colours identified in the key at bottom. Each element is represented by its chemical symbol. Above each symbol is the element's atomic number, and below it is the element's name, as shown in the labelled example at lower right

© VICTOR HABBICK VISIONS/SCIENCE PHOTO LIBRARY

Map of the world, 1660

17th century map of the world. Published in Amsterdam in 1660, this map by the Dutch cartographer Frederick de Witt (1630-1706) shows the expanding exploration of the known world. The map divides the Earth into a western and eastern hemisphere. In the upper corners are the constellations of the northern and southern celestial poles, with the geographical poles in the lower corners. Above and below the hemispheres are the Aristotlean elements of Air, Fire, Earth and Water. At upper centre is the Sun, with the Earth orbiting on an ecliptic ring of zodaical symbols. At lower centre, Ptolemy's geocentric cosmology (left) is contrasted with the heliocentric Copernican cosmology (right)

© Library Of Congress, Geography And Map Division/Science Photo Library