Science Policy in the U.S.S.R.
A new study shows that the U.S.S.R. operates a research and development establishment comparable in size to that of the U.S. The differences between the two are getting fewer
Features
Nuclear Tracks in Solids
Charged particles leave damage trails in nonconducting solids such as mineral crystals, glasses and plastics. The etched tracks provide information on the age of the solid or the nature of the particles...
Wound Healing
In man and other higher animals an intricate, three-step process involving a variety of cells renews injured tissue. Studies of this process could yield ways of controlling several diseases...
Truth and Proof
The antinomy of the liar, a basic obstacle to an adequate definition of truth in natural languages, reappears in formalized languages as a constructive argument showing not all true sentences can be proved...
Hormones in Social Amoebae and Mammals
The substance that attracts social amoebae to one another to form a sluglike mass has recently been identified. It turns out that the same substance also acts as a "messenger" in mammalian cells...
Ultraviolet Astronomy
Telescopes now in orbit are measuring the ultraviolet radiation from celestial objects that never penetrates the earth's atmosphere. The results may significantly alter man's view of the universe...
The Phalarope
The reproductive behavior of this aquatic shorebird is most unusual. The female phalarope aggressively courts the male; the male phalarope warms the eggs and rears the young birds
Analytic Instruments in Process Control
Self-regulating manufacturing processes call for systems that sensitively monitor the performance of the process. An example of such a system is a gas chromatograph linked to a computer
Departments
50 and 100 Years Ago: June 1969
Science and the Citizen: June 1969
- Letters
Letters to the Editors, June 1969
- Recommended
Books
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist
- Departments
The Authors
Bibliography
