Scientific American Magazine

Perhaps as many as 2,500 substances are currently being added to foods for flavoring, coloring, preservation and other purposes. How are the necessity and safety of these substances determined?

In the brains of some vertebrates are unidentified organs that respond to daylight. Experiments with blinded birds demonstrate that these organs control biological rhythms

A geosyncline is a huge deposit of sedimentary rock that forms at the edge of a continent. When it is compressed, it buckles up into a mountain range. It also enables a continent to grow by accretion

The field around a charged body is used to manipulate particles of matter. Among the modern applications of electrostatics are fly-ash precipitators, paint sprayers and Xerox copying machines

This large-headed species lived from the Pyrenees to the Caspian Sea during the Ice Age. One cave alone has yielded the remains of 30,000 such bears. What caused the species to become extinct?

They supposedly know the world only in terms of sensory impressions and motor activities. New experiments suggest that their cognitive, or hypothesis-forming, development begins at the age of nine months

The immediate source is adenosine triphosphate (ATP). The ultimate sources are the combustion of food and the breakdown of glycogen. The time relations of these processes offer some practical hints

It is generally assumed that he did so by calculating the distances between a planet and the sun and then perceiving that the distances fitted into an ellipse. It is more likely that the ellipse came first