Scientific American Magazine

Land-based missiles are giving way to submarine missiles as a secure deterrent to a nuclear first strike. The question now is whether or not the U.S. should spend perhaps $40 billion on a new missile fleet

The rejection of transplanted organs has focused attention on the body's ability to distinguish foreign cells from its own. The cells of each individual are uniquely marked with protein

The meteorites known as carbonaceous chondrites contain organic compounds. These compounds have now been subjected to detailed analyses which indicate that they are not of biological origin

The community of plants and animals that builds tropical reefs is descended from an ecosystem of two billion years ago. The changes in this community reflect major events in the history of the earth

The flight muscles of certain insects cannot function properly until they have been warmed up by a process that resembles shivering. The system also keeps the insect from overheating

This mathematical theory has restored infinitesimals to good standing. They had been employed since antiquity, but often with doubts, to solve such problems as finding a circle's area

We see contours when adjacent areas con trast sharply. Surprisingly, certain contours, in turn, make large areas appear lighter or darker than they really are. What neural mechanisms underlie these effects?

A new technique separates the psychological and physical factors in stressful conditions. In studies with rats the psychological factors were the main cause of stomach ulcers and other disorders