Images Dated 17th March 2006

Two Ways Of Life

Swedish photographer Rejlander's most famous work, The Two Ways Of Life, a combination print comprised of over thirty separate images, 1857. A philosopher presides over the choice of two young men between a life of indolence, gambling and vice (left) and a life of industry, virtue, study and religion (right). (Photo by Oscar Gustav Rejlander/Hulton Archive/Getty Images)

© 2006 Getty Images

Errol, NH. Ostrich Fern, Matteuccia Struthiopteris, next to a small tributary of

Errol, NH. Ostrich Fern, Matteuccia Struthiopteris, next to a small tributary of the Androscoggin River. 13 Mile Woods. Northern Forest, Great North Woods

© Jerry Monkman / DanitaDelimont.com

Danita Delimont, Errol, Fern, Flowing, Great North Woods, New Hampshire, North America, Northern Forest, River, Time Lapse, Tourism, Usa, Wildflower

Spectral classes of star

Spectral classes of star, computer artwork. There are seven main classes of star, categorised according to their temperature and spectrum. These are, from left to right, called O, B, A, F, G, K and M. The surface temperature determines their colour, and decreases from left to right. O stars are extremely hot and emit much of their radiation in the ultraviolet. B stars are slightly cooler but still extremely powerful, and A stars are cooler still but still appear white. F stars appear slightly yellow, while G stars, of which the Sun is one, appear yellower still. K stars appear orange, while M stars, the most common type in the galaxy, appear red

© CHRISTIAN DARKIN/SCIENCE PHOTO LIBRARY