Images Dated 17th January 2005

Planetesimal asteroids in the early solar system

Solar system formation. Artwork of asteroids (planetesimals) in the early solar system about 4.7 billion years ago. The planetesimals lie in an interstellar cloud (nebula) of gas and dust that surrounds the Sun. The solar system was formed when this nebula contracted due to gravitational forces; this process was possibly triggered by shock waves from a nearby exploding star (super- nova). The planets were formed by a process called accretion in which dust particles collided and to form planetesimals. These in turn attracted dust, gas and other planetesimals by gravitational attraction to form larger bodies

© DETLEV VAN RAVENSWAAY/SCIENCE PHOTO LIBRARY

Zenobe Gramme

Zenobe Gramme (1826-1901), Belgian electrical engineer in his workshop. Gramme was interested in improving the efficiency of electrical devices. In 1710 he demonstrated the Gramme machine, a continuous-current generator that produced large currents in relation to its size. At an exhibition in Vienna, Austria, a technician wired a series of such machines together incorrectly, so that the wires from one which was running were joined to one which was not. To the amazement of the onlookers, the second machine began to turn: the Gramme machine could act as both a generator and a motor. This allowed the possibility for work to be transferred large distances via electricity. Taken from Physique Populaire, 1891

© SHEILA TERRY/SCIENCE PHOTO LIBRARY

Africa, from Fra Mauros world map, 1457

Africa, from Fra Mauro's Great Map of the World, 1457. Fra Mauro was a 15th century Italian monk and cartographer. In producing this map, which has been inverted from the original to put north at top, Mauro was forced to alter the land masses to fit his Christian doctrine. According to the Apocrypha, the Earth is six-sevenths land. Mauro drew oceans and continents to fit this belief. The original is held in the Bibliotecha Marciana in Venice, Italy. Taken from A Book of Discovery (1912) by M.B. Synge

© SHEILA TERRY/SCIENCE PHOTO LIBRARY