Scientific American Magazine Vol 226 Issue 4

Scientific American Magazine

Volume 226, Issue 4

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Features

Political Factors in Economic Assistance

It is argued that the global downward trend in aid from the rich countries to the poor countries can be reversed only by stressing the moral argument

Gunnar Myrdal

Collective-Effect Accelerators

The collective "self-fields" generated by intense beams of electrons can be harnessed to accelerate positive particles to high energies. In one case the electrons are first curled into ring-shaped clusters

Denis Keefe

An Earlier Agricultural Revolution

It has generally been assumed that man first domesticated plants and animals in the Middle East. Excavations in Southeast Asia now suggest that there the revolution began some 5,000 years earlier

Wilhelm G. Solheim II

Tides and the Earth-Moon System

Tidal friction in shallow waters has controlled the evolution of the earth-moon system for aeons. It is causing the length of the day to increase and the moon to recede from the earth

Peter Goldreich

The Structure and History of an Ancient Protein

To oxidize food molecules all organisms from yeasts to man require a variant of cytochrome c. Differences in this protein from species to species provide a 1.2-billion-year record of molecular evolution

Richard E. Dickerson

Language and the Brain

Aphasias are speech disorders caused by brain damage. The relations between these disorders and specific kinds of brain damage suggest a model of how the language areas of the human brain are organized

Norman Geschwind

Superconductors for Power Transmission

The rising demand for electricity conflicts with opposition to overhead transmission lines. Underground lines that are refrigerated to be superconducting may provide a solution

Donald P. Snowden

Environmental Control in the Beehive

Honeybees efficiently regulate temperature and humidity, eliminate polluted air, remove foreign objects, wastes and dead bodies and control parasites and pathogens that attack them and their food

Roger A. Morse

Departments

Letters to the Editors, April 1972

50 and 100 Years Ago: April 1972

The Authors

Science and the Citizen: April 1972

Mathematical Games

The Amateur Scientist

Books

Bibliography