Public Policy on Fertility Control
In the u.s. over the past dozen years policy on contraception has been almost entirely reversed. The transformation reflects the concern of the community with population size and poverty...
Features
The Physics of Brasses
A trumpet produces musical tones when the vibrations of the player's lips interact with standing waves in the instrument. These waves are generated when acoustic energy is sent back by the instrument's bell...
Advanced Composite Materials
Materials in which the properties of one component enhance those of another are steadily evolving. As the cost of exotic components comes down, the advanced materials will show up in everyday uses...
The Immune System
This diffuse organ has the assignment of monitoring the identity of the body. Its basic constituents are lymphocytes and antibody molecules, which recognize both foreign molecules and one another...
Meteorites and Cosmic Radiation
Before a meteorite falls to the ground it has been bombarded in the vacuum of space by cosmic ray particles. The nuclear products of this bombardment are clues to the history of the solar system...
The Brideprice of the Sebei
In this African culture getting a bride costs a man a substantial fee in cattle, cash, clothing, pots, tobacco, milk, beer and other commodities. To what extent is the transaction strictly economic?...
Plate Tectonics and Mineral Resources
The concepts of continental drift and sea-floor spreading provide clues to the location of economically important minerals such as oil and metals. These clues have already led to promising deposits...
Brain Mechanisms in Movement
The highest brain functions are generally thought to be mediated in the cerebral cortex. In the control of the muscles, however, the highest function may be served by centers deeper in the brain...
Departments
50 and 100 Years Ago, July 1973
Science and the Citizen, July 1973
- Letters
Letters to the Editors, July 1973
- Recommended
Books, July 1973
- Mathematical Recreation
Mathematical Games, July 1973
- Amateur Scientist
The Amateur Scientist, July 1973
- Departments
The Authors, July 1973
Bibliography, July 1973
