Images Dated 27th February 2003

Sea cucumber

Sea cucumber (Thelenota sp.) spawning. Microscopic sex cells (gametes) are being released to allow fertilisation (the fusing of a male and a female sex cell). The resulting larvae may grow into adult sea cucumbers. This marine invertebrate is a member of a group of animals (echinoderms) that includes starfish. A sea cucumber lives on the sea floor, crawling on its projecting tube feet, but mostly remaining motionless and gathering its food from the water. It feeds on microscopic sea life (plankton) and also extracts nutrients from the surrounding mud. Sea cucumbers range in length from 2 centimetres to 2 metres. They are found worldwide. Photographed in the Red Sea

© PETER SCOONES/SCIENCE PHOTO LIBRARY

Linear accelerator

TESLA accelerator component. Technician in clean room clothing checking a resonator for use in the TESLA (Tera-electron Volt Energy Superconducting Linear Accelerator). This niobium resonator will be cooled to -271 degrees Celsius, 2 degrees above absolute zero, at which temperature it will become a superconductor. A 33 kilometre path of these will accelerate electrons and positrons (anti- electrons) using magnetic fields, colliding them at the path's centre. This will be used to study the nature of matter in the universe. In addition to this, the facility will be able to create X-ray lasers, which will be able to visualise individual atoms. This work is being done at DESY in Germany

© DAVID PARKER/SCIENCE PHOTO LIBRARY