Scientific American Magazine Vol 226 Issue 2

Scientific American Magazine

Volume 226, Issue 2

You are currently logged out. Please sign in to download the issue PDF.

Features

Technology Assessment and Microwave Diodes

The advent of cheap solid-state devices for the generation of microwaves provides a rare opportunity for attempting to predict the impact of a technological development on society

Jeffrey Frey, Raymond Bowers

Brain Changes in Response to Experience

Rats kept in a lively environment for 30 days show distinct changes in brain anatomy and chemistry compared with animals kept in a dull environment. The implications of these effects for man are assessed

Edward L. Bennett, Marian Cleeves Diamond, Mark R. Rosenzweig

The Structure of Cell Membranes

The thin, sturdy envelope of the living cell consists of lipid, phosphate and protein. The proteins act as both gatekeepers and active carriers, determining what passes through the membrane

C. Fred Fox

The Synthesis of Speech

Electronic speaking machines capable of synthesizing output speech with no recourse to any vestige of human speech are in the process of development. They may provide articulate voices for computers

James L. Flanagan

The Pressure of Laser Light

The forces exerted by a focused beam of laser light are strong enough to push tiny particles around freely in various mediums. Several applications based on this recent finding are proposed

Arthur Ashkin

Intercontinental Radio Astronomy

The structure of quasars and of other radio sources is being examined with interferometers consisting of radio telescopes separated by distances approaching the diameter of the earth

K. I. Kellermann

The Physiology of Meditation

Is the meditative state that is achieved by yogis and other Far Eastern mystics accompanied by distinct physiological changes? A study of volunteer subjects in the U.S. indicates that it is

Robert Keith Wallace, Herbert Benson

Checks on Population Growth: 1750-1850

In this period the population of Europe nearly doubled, but without certain checks it would have grown even more. There is much evidence that the checks were the widespread practice of celibacy and infanticide

William L. Langer

Departments

Letters to the Editors, February 1972

50 and 100 Years Ago: February 1972

The Authors

Science and the Citizen: February 1972

Mathematical Games

The Amateur Scientist

Books

Bibliography