Scientific American Magazine

There is no longer any doubt that cigarette smokers have a higher death rate than nonsmokers. New biological, studies help to explain how tobacco smoke damages the lungs, heart and other body tissues

Earthquake waves indicate that at a depth between 37 and 155 miles the stuff of the earth is less rigid than that above and below it. Such a layer would have an important bearing on tectonic processes

In which large sharks are studied at close range to assess the role of their various senses in their feeding behavior. The results give promise that the problem of preventing shark attacks can be solved

They are substances in which a molecular structure encloses atoms or molecules of another kind. They are finding uses in industry and play a role in the chemistry of the living cell

Some fossils are so small they can be identified only with the aid of a magnifying glass or a microscope. They label sedimentary layers and provide excellent clues to ancient changes in climate

The molecule of the hereditary material deoxyribonucleic acid (DNA) normally consists of two interwoven strands. The discovery of a form with only one strand promises to clarify how the molecule replicates

When the moon is near the horizon, it looks at the zenith. Is this because the observer bigger than when it is raises his eyes to see the zenith moon or because he views the horizon moon over terrain?

The operation of the network linking the 75 million telephones in the U.S. requires fast and efficient switching. Present electromechanical switching systems may soon be replaced by even faster electronic ones