Specialist Imaging Gallery

Electromagnetic particle shower

Electromagnetic particle shower. Particle tracks (moving from bottom to top) showing multiple electron-positron pairs created from the energy of a high-energy gamma ray photon produced by a neutrino collision. The positron is the anti-particle of the electron, and this process is called pair-creation. Electrons and positrons are charged particles and form these paired spirals as they curve away from each other in a magnetic field. As they do so, they radiate photons, which can in turn produce new electron-positron pairs. This shower of particle creation continues until the energy of the original photon is used up. The region shown here is about 2 metres tall

© GORONWY TUDOR JONES, UNIVERSITY OF BIRMINGHAM/SCIENCE PHOTO LIBRARY

Aster seed, SEM

Aster seed. Coloured scanning electron micrograph (SEM) of a seed from an aster flower (Aster sp.). The structures seen here are the cypsela (lower frame) and a large pappus (upper frame). The pappus aids in wind dispersal. The cypsela is a type of achene, a specialised dry fruit, and the actual seed is inside the cypsela. A seed contains an embryo (a fertilised ovule from which a new plant can grow), and a supply of food. Seed dispersal methods include being carried by the wind, or water or on animal coats, or being eaten and deposited in animal droppings. Aster flowers are mostly native to Eurasia, and are a popular garden plant. Magnification: x420 when printed 10 centimetres tall

© Steve Gschmeissner/Science Photo Library

"Salvinia Effect" of Salvinia natans

Scanning electron micrograph of leaf detail of Salvinia natans, a floating fern type plant which has superhydrophobic trichomes or hairs on the upper surface of its leaves. Each of these eggbeater shaped hairs exhibits a hydrophilic tip on the top of each hydrophobic hair. The combination of a hydrophobic surface with hydrophilic tips is called the "Salvinia Effect". These air retaining surfaces are of great interest, particularly with regards to fuel consumption when applied to ships having to overcome friction produced by the drag of water on their hulls. This drag could be reduced dramatically with the "Salvinia Effect", a layer of air between the ship's hull and the water, saving vast amounts of fuel. A suggested estimated saving of 20 million tons of oil per year for just a 10% decrease in drag for shipping alone. Magnification: x372 (x122 at 10cm wide)

© POWER AND SYRED/SCIENCE PHOTO LIBRARY