Images Dated 28th May 2002

Warped space-time

Warped space-time. Conceptual computer artwork of bent grid lines around an astronomical object, representing warped space-time. Einstein conceived of space-time in his Special Theory of Relativity. He showed that space and time are not invariant, but change with the velocity of an object. These changes are noticeable near the speed of light and space and time must be treated a single space-time framework. In his General Theory of Relativity, Einstein then explained the phenomenon of gravity as a distortion of this space-time. Massive and super-dense astronomical objects such as white dwarfs, neutron stars or black holes would produce this kind of severe warping of space-time

© JULIAN BAUM/SCIENCE PHOTO LIBRARY

LM of a cross section through alveoli in the lung

Lung alveoli. Light micrograph of a cross section through lung tissue showing alveoli. Making up the frame (spongy appearance) are tiny air sacs called alveoli. The alveolar walls (pink) are lined with a one-cell thick layer of epithelium. Breathed in air diffuses through the epithelium to a rich network of capillaries in the walls. This is where exchange of gases (oxygen and carbon dioxide) takes place. Oxygen will be carried by the capillary blood to the heart. At the same time carbon dioxide will diffuse out of the blood into the lung and will be breathed out. Magnification: x64 at 35mm size

© SINCLAIR STAMMERS/SCIENCE PHOTO LIBRARY