Images Dated 6th June 2003

Art of Diatom algae (from Ernst Haeckel)

Diatoms. Computer-enhanced engraving of assorted species of diatom. Diatoms are a group of single- celled algae. The two main morphological types of diatom are represented here: pennate (rod-shaped) and centric (rounded). A characteristic feature of diatoms is their intricately patterned, glass-like cell wall, or frustule. The frustule consists of two halves which fit together like the lid and bottom of a box. It is often decorated with rows of tiny holes, known as striae. Diatoms form an important part of the floating plankton in the marine and freshwater food chains. Engraving taken from Ernst Haeckel's famous treatise: "Art Forms of Nature" (1904)

© MEHAU KULYK/SCIENCE PHOTO LIBRARY

Photomultiplier tube

Photomultiplier tube (PMT) held by technician Giuseppe Dipietro of the Gran Sasso Laboratory. 2200 PMTs are incorporated into the Borexino neutrino detector (not seen). Neutrinos are elementary particles produced by nuclear reactions in stars and in supernova explosions. The PMT detects the flash of light when a neutrino hits the liquid core of the detector. The Borexino detector measures neutrino flux from the Sun. The Gran Sasso Laboratory is in Abruzzo, Italy. The neutrino detector is located 1400 metres underground and is accessed from a 10 kilometre long road tunnel. The rock overlay shields the laboratories from cosmic rays

© VOLKER STEGER/SCIENCE PHOTO LIBRARY

Wilhelm Roentgen, German physicist

Illustrtion of the German experimental physicist Wilhelm Konrad Roentgen, 1845-1923, discoverer of X-rays. While using a discharge tube (in which an electric discharge is passed through a gas at low pressure) in a darkened room, he noticed that a card coated with barium platinocyanide glowed when the tube was switched on. The effect was not blocked by an intervening wall, or even a thin sheet of metal. Roentgen termed this newly discovered phenomenon X-ray radiation, & suggested that it consisted of electromagnetic rays with a shorter wavelength than light. He was awarded the first Nobel Prize for physics in 1901. Illustrated by the artist Bill Sanderson 1995

© BILL SANDERSON/SCIENCE PHOTO LIBRARY