Scientific American Magazine

The members of India's lowest castes have traditionally suffered harsh social and economic discrimination. Such discrimination is now prohibited by statute and is slowly beginning to give way

When a muscle contracts, one kind of filament within it slides past another kind. Electron microscopy and other techniques have begun to disclose how the filaments exert a force on each other

Of seven mirrors invented by physicists to describe the symmetry of the laws of nature, three have been shattered. Of those remaining, only one may still be wholly intact. It is called the CPT "mirror"

They have evolved some remarkable a adaptations to their hosts. Perhaps the most remarkable is found in the European rabbit flea, the breeding cycle of which is regulated by the reproductive hormones of the rabbit

The information gathered by rockets and artificial satellites has contributed to a new physical description of the aurora in which the earth's magnetosphere acts like a gigantic cathode-ray tube

It is clear that this baffling disease, which often damages the heart, sterns from streptococcal infection. No link has yet been found, however, between the infection and the rheumatic process

Plants, like animals, must regulate their temperature In order to function at optimum physiological efficiency. This is accomplished through three mechanisms: radiation, transpiration and Convection

Most musical instruments produce tones whose partial tones, or overtones, are harmonic: their frequencies are whole-number multiples of a fundamental frequency. The piano is an exception