Skip to main content


Food Additives

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?...

By G. O. Kermode

Nonvisual Light Reception

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

By Michael Menaker

Geosynclines, Mountains and Continent-Building

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...

By Robert S. Dietz


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...

By A. D. Moore

The Cave Bear

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?...

By Bjrn Kurtn

Do Infants Think?

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...

By Jerome Kagan

The Sources of Muscular Energy

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...

By Rodolfo Margaria

How did Kepler Discover his First Two Laws?

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...

By Curtis Wilson


  • 50 and 100 Years Ago: March 1972

  • Science and the Citizen: March 1972

  • Letters

    Letters to the Editors, March 1972

  • Recommended


  • Mathematical Recreation

    Mathematical Games

  • Amateur Scientist

    The Amateur Scientist

  • Departments

    The Authors

  • Bibliography

Purchase To Read More

Already purchased this issue? Sign In to Access
Select Format
Scroll To Top