A Bilateral Nuclear-Weapon Freeze
In many of the current elections in the U.S. there is a referendum on whether to urge a halt in the production of new nuclear weapons and delivery systems. The nature of such a freeze is discussed here
Volume 247, Issue 5
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Features
The Harvesting of Interacting Species in a Natural Ecosystem
The changing populations of whales and other animals that feed on the knll of the Southern Ocean are an example of the problem of utilizing a biological resource without extinguishing species
The Growth of Western North America
Over the past 200 million years the continent has been extended westward by repeated collisions with smaller land masses, some of which appear to have come from thousands of kilometers away
A Genetic Switch in a Bacterial Virus
Two regulatory proteins interact with a region of viral DNA to turn one set of genes off and another on in response to an environmental change. The switch is described in terms of its molecular structure
Glueballs
They are "atoms of color," bound states of the particle that transmits the color force, the strongest force known. A few of them may have been detected in high-energy experiments
The Ecological Physiology of a Garter Snake
In order to survive in the harsh environment of western Canada the red-sided garter snake has evolved a precisely timed cycle of physiology and behavior with several spectacular features
The Physics of Kettledrums
The vibrations of a violin string form a harmonic series with a distinct pitch. The vibrations of an ideal membrane do not form such a series. How, then, can a kettledrum have a pitch?
The First Nuclear Industry
It flourished in the first third of the 20th century when the prized element was not uranium but radium. Tons of ore had to be mined and processed to extract a single gram