The Mohole
The U. S. may drill a hole to the Mohorovicic discontinuity between the earth's crust and the underlying mantle. The hole would provide priceless evidence on the earth's history and internal constitution
Features
Family Planning in the U.S.
Where the birth rate of the U. S. was once fairly stable, practices of contraception have now made it a variable. How these practices affect population trends has been examined by a large-scale study
Visual Perception and Personality
Experiments with specially distorted rooms reveal that the way in which we perceive the size and even the shape of others is powerfully influenced by our emotional relationship with them
Germination
Many plants have evolved natural mechanisms that keep their seeds "dormant" until the optimal time for sprouting. These mechanisms include chemical responses to light and rainfall
The Solar System beyond Neptune
Pluto, our sun's most remote and mysterious planet, may once a satellite of Neptune. Current theories about its origin provide new clues to the genesis of the solar system
How Reptiles Regulate their Body Temperature
Although they lack internal controls, they can maintain a high temperature by their behavior. A lizard, for example, can raise its temperature by changing the position of its body in the sun
Aligned Crystals In Metals
Crystals have different properties in different directions. Alignment of the crystal grains within a piece of metal can significantly alter its mechanical and magnetic behavior
The Sex Gas of Hydra
Usually this small animal reproduces by budding, but it can also develop male and female organs for sexual reproduction. What factors determine which method of reproduction it uses?
Departments
50 And 100 Years Ago: April 1959
Science And The Citizen: April 1959
- Letters
Letters to the Editors, April 1959
Errata
- Recommended
Books
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist
- Departments
The Authors
Bibliography
