Scientific American Magazine

Ethical issues are raised when a treatment is prescribed that, unknown to the patient, cannot have any specific effect on his condition. The practice is often deceptive, the author finds, and should be restricted

The general theory of relativity has many competing successors. For such theories to be viable they have to meet observational and theoretical criteria that are steadily becoming more rigorous

After a cautious introduction, computers now play a critical role in ensuring the security and economy of the large networks that distribute electric power

The highly diversified cells that defend the body against foreign substances derive from a single kind of precursor. Differentiation of the cells is controlled by the environment in which they mature

Contrasts in loudness make music exciting. Many performers do not, however, produce the variations composers expect from them

The head of the animal is so far above the heart and the lungs that the task of supplying it with oxygenated blood calls for a remarkably high blood pressure and unusually deep breathing

The visible details of an object often consist of contrasting areas with a regular spacing, or spatial frequency. The visual system is more sensitive to certain of these frequencies than it is to others

As one might expect, working women spend less time in housework than their mothers and grandmothers did some 50 years ago. Women who are not in the labor force, however, spend just as much time