Scientific American Magazine

If the U.S. must have sources of energy other than fossil fuels, the only source that can make a major contribution between now and the end of the century is nuclear fission

They apparently formed over the entire span of the planet's history. Their remarkable size may be related to the fact that the crust of Mars is not divided into moving plates

At least one particle that fits none of the established families has emerged from experiments with high-energy neutrinos. The new particle must exhibit some hitherto unobserved property of matter

An operator is a segment of DNA adjacent to a gene; a repressor is a protein that binds to the operator and controls the expression of the gene. How such a system works in a virus is explored in detail

These shrimplike creatures are formidable predators. Two of their forward appendages are adapted either for spearing or for smashing. One blow from a smasher can break the shell of a good-sized clam

Tracing changes in the relation between brain size and body size in various groups of fossil and contemporary animals sheds light not only on the evolution but also on the nature of intelligence

There are several types of apparition to be seen across the sea or the land. Each has an explanation in terms of the optical properties of a fluid medium: the atmosphere

Long before he introduced inoculation with cowpox, smallpox was prevented by inoculation with smallpox itself. The procedure was risky, but its spread in the 18th century set the stage for Jenner