Images Dated 14th August 2003

Mirror mount testing for the Very Large Telescope

VLT mount manufacture. Manufacture of the mount for the Very Large Telescope (VLT) which will be based at the European Southern Observatory site at Cerro Paranal, Chile. The mount will carry an 8.2- metre diameter mirror. The mirror's weight & size is being simulated by a mock-up (brown, at lower centre). This 500-tonne azimuthal mount can rotate the mirror vertically & horizontally. The VLT will consist of 4 such telescopes mounted side by side. Together they will have the light-collecting power of a 16-metre mirror, making the VLT the world's largest optical telescope. The VLT is due to be completed soon after 2000. Photographed in 1997 at the Ansaldo Energia factory near Milan, Italy

© DAVID PARKER/SCIENCE PHOTO LIBRARY

Piece of crude silicon rock

Silicon. Sample of crude-refined silicon. Silicon is a semiconductor group IV metal, with atomic number 14. It is not found as a native element, but is the second most abundant element in the Earth's crust, occurring as silica (silicon dioxide). Crude silicon may be obtained by reducing silica with carbon in a furnace. Pure silicon is obtained by conversion to silicon tetrachloride, then reduction on a hot wire and zone refining. Exceptionally pure silicon is used as the substrate for electronic devices. Its diamond-type lattice structure means that it may be doped with electron donors or acceptors to form transistors and diodes

© PASIEKA/SCIENCE PHOTO LIBRARY

Cartilage

Hyaline cartilage. Light micrograph of a section through hyaline cartilage. This semi-rigid connective tissue is composed of many chondrocytes (cartilage cells, dark purple and blue). These synthesize an extracellular matrix (purple) of proteoglycans, collagen and water that keeps them apart from each other in spaces known as lacunae (white). Hyaline cartilage is strong but compressible due to its high water content. It provides structural support to various parts of the body such as the windpipe (trachea). Toluidine blue stain. Magnification: x190 at 35mm size

© Innerspace Imaging/Science Photo Library