Images Dated 24th January 2005

Physics experiment

Physics experiment. Screen display of the output from a physics experiment. The experiment involves monitoring changing position with time. The graph shows the position of an object (given as distance in metres) plotted against time (in seconds). The output is a wave of decreasing amplitude. Motion of this sort is seen in a damped oscillator, such as a mass bouncing on a spring, or the swinging of a pendulum. The gradient of the graph shows the velocity of the object. The velocity is zero at the peaks (the high points of a swinging pendulum) and at a maximum in between (the low point of the swing of a pendulum)

© ANDREW LAMBERT PHOTOGRAPHY/SCIENCE PHOTO LIBRARY

Sperm whale and giant squid

Sperm whale and giant squid. Computer artwork of a sperm whale (Physeter catodon, or macrocephalus, left) hunting a giant squid (Architeuthis sp. at right). Sperm whales can reach 18 metres in length and giant squid can be up to 10 metres long. Sperm whales are toothed whales (teeth seen in lower jaw), though the teeth are thought to be used in aggression between males, rather than eating. Sperm whales dive deep (over 1000 metres) to hunt their main prey, giant squid. The squid can defend itself with suckers and sharp beak, and scars are found on whales from these defences. However, the giant squid is rarely seen, most often found in a sperm whale's intestines or washed up on a beach

© CHRISTIAN DARKIN/SCIENCE PHOTO LIBRARY

Static electricity

Static electricity. Strips of paper that have been electrically charged by a Van de Graaff generator, a device that generates static electricity. Charge accumulates on the metal dome and is transferred to the paper. When uncharged, the strips of paper hang downwards under gravity, but when they are electrically charged they repel each other and move upwards and apart (as is seen here). This is possible because the electrical force is stronger than gravity. The two opposing types of electrical charge (positive and negative) usually cancel out, but excess charge (as here), clearly demonstrates the greater strength of the electrical force

© ANDREW LAMBERT PHOTOGRAPHY/SCIENCE PHOTO LIBRARY