Sphere Gallery

Global water and air volume

Global water and air volume. Conceptual computer artwork of the total volume of water on Earth (left) and of air in the Earth's atmosphere (right) shown as spheres (blue and pink). The spheres show how finite water and air supplies are. The water sphere measures 1390 kilometres across and has a volume of 1.4 billion cubic kilometres. This includes all the water in the oceans, seas, ice caps, lakes and rivers as well as ground water, and that in the atmosphere. The air sphere measures 1999 kilometres across and weighs 5140 trillion tonnes. As the atmosphere extends from Earth it becomes less dense. Half of the air lies within the first 5 kilometres of the atmosphere

© Adam Nieman/Science Photo Library

Durers Celestial Globe, 1515

Durer's Celestial Globe, 1515. This shows the northern hemisphere, and was prepared in conjunction with the astronomer Stabius. Four astronomers are shown in the corners: Aratus Cilis; Ptolomaeus Aegyptius; Maniliusromanus; and Azophi Arabus (al Sufi). Albrecht Durer (1471- 1528) produced the first printed star charts in 1515. One chart, or planisphere, showed all the northern constellations; the other depicted the southern hemisphere. The positions of the stars were exactly fixed (according to Ptolemey's catalogue) and the figures were artistically portrayed, in a classical style. Durer also chose to illustrate the constellations that would appear on a globe as if seen from space. Taken from The Complete Woodcuts of Albrecht Durer by Dr Willi Kurth (1936)

© SHEILA TERRY/SCIENCE PHOTO LIBRARY

Internet blog map

Internet blog map. Computer generated map showing relationships between internet weblogs (blogs). Blogs are internet sites where entries are made in journal style and shown in reverse chronological order. Blogs usually feature a large number of links to other sites. The blogging community is known as the blogosphere. This map shows blogs as nodes (coloured spots) and lines represent the links between them. Nodes within the centre are blogs based on technical discussion and gadgetry. Nodes at the outer part of the sphere are non- technical blogs that link to the centre. Colours represent the URL, where blogs hosted at the same domain have the same colour. This image was created by Matthew Hurst

© MATTHEW HURST/SCIENCE PHOTO LIBRARY