Scientific American Magazine

By most standards they are quite safe. Three Mile Island nonetheless confirmed that decisions about their future call for greater reliance on quantitative methods of assessing risks presented by such systems

There is something small and hard inside. These objects, which may be the particles called quarks, are seen most clearly when a violent collision of particles gives rise to a "jet" of debris

These three names refer to the same city of northern England through Roman, Viking, medieval and modern times. A major archaeological campaign is uncovering material evidence of its 2,000-year history

The activities of the cells of the body are integrated by mediator substances that interact with specific receptors. It appears that many diseases are attributable to errors in such communication

Puzzling changes in the orbital period of Comet Encke, which circles the sun every 3.3 years, can be attributed to the rotation of its icy nucleus and the thrust of gases evaporated from it

The history of this ancient family of electron-transferring proteins suggests that our metabolic ancestors may have been photosynthetic bacteria for which respiration was only a standby energy mechanism

Divers, gymnasts, astronauts and cats can do rotational maneuvers in midair that may seem to violate the law of the conservation of angular momentum but in fact do not

The formidable appendages of these insects look as though they were meant for stabbing or pinching an opponent. Actually most of the horns are used to pry up or lift a rival of the same species