Nuclear-Free Zones
The failure of recent attempts to revitalize the Nonproliferation Treaty has led to renewed interest in regional multinational pacts as an alternative way of preventing the spread of nuclear weapons...
Features
The Protein Switch of Muscle Contraction
The contraction of muscle is "turned on" when calcium ions trigger changes in the conformation of two regulatory proteins: tropomyosin and troponin. The detailed nature of these changes is now emerging...
High-Gradient Magnetic Separation
A recent advance in the generation of strong magnetic fields opens the way to removing very weakly magnetic particles from mixtures. One novel application of the new process is purifying wastewater...
The Cancer Problem
Almost all cancers appear to be caused by exposure to factors in the environment. The most promising approach to the control of the disease is to identify those factors and eliminate them...
Unusual Mechanisms for the Generation of Lift in Flying Animals
Some birds and insects that hover cannot generate enough lift by means of standard aerodynamics. A close study of hovering shows that they employ two mechanisms that are best described as clap-fling and flip...
The Subduction of the Lithosphere
The rocky shell of the earth grows outward from mid-ocean ridges. Ultimately it plunges into the mantle below, giving rise to oceanic trenches, earthquakes, volcanoes, island arcs and mountain ranges...
The Synthesis of Diamond at Low Pressure
Natural diamonds and most man-made ones form at high pressure. It is also possible to synthesize diamond by growing it from existing diamonds in a low-pressure gas rich in carbon
The Role of Pupil Size in Communication
Changes in attitude can be detected by measuring changes in pupil size. It now appears that enlarged or constricted pupils can also affect the attitude and responses of the person who observes them...
Departments
50 and 100 Years Ago, November 1975
Science and the Citizen, November 1975
- Letters
Letters to the Editors, November 1975
- Recommended
Books, November 1975
- Mathematical Recreation
Mathematical Games, November 1975
- Amateur Scientist
The Amateur Scientist, November 1975
- Departments
The Authors, November 1975
Bibliography, November 1975
