Toxic Substances and Ecological Cycles
Radioactive elements or pesticides such as DDT that are released in the environment may enter meteorological and biological cycles that distribute them and can concentrate them to dangerous levels...
Features
The Heart's Pacemaker
A group of specialized cells regulates the fundamental rhythm of an animal's heart. The pacemaker also limits the heart's range of responses to the influences of nerves and hormones
Ancient Ararat
Sometimes called Urartu, it was a powerful nation of the region around Mount Ararat in 800 B.C. A mound in Turkey has yielded much information about this nation and its widespread influence...
The Surface of the Moon
Nine spacecraft have provided thousands of closeup pictures of the moon. Although they have revealed much never seen before, they have not solved the riddle of the moon's nature and origin...
Behavioral Psychotherapy
Abnormal behavior can be thought of not as a symptom of a hidden illness but as a problem of "social learning", and can be treated directly by methods of that are derived from principles of learning...
Salt-Water Agriculture
Experiments in Israel indicate that many plants can be irrigated with salty water, even at oceanic strength, if they are in sandy soil. The technique might open much barren land to agriculture...
The Origin of the Automobile Engine
The first internal-combustion engine to operate successfully on the four-stroke cycle was built in 1876 by Nicolaus August Otto. His "Silent Otto" was a good machine with a poor theory
Advances in Superconducting Magnets
In the past five years superconducting magnets have developed from a laboratory curiosity into the most practical means of generating intense magnetic fields for a growing number of research projects...
Departments
50 and 100 Years Ago: March 1967
Science and the Citizen: March 1967
- Letters
Letters to the Editors, March 1967
- Recommended
Books
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist
- Departments
The Authors
Bibliography
