External Human Fertilization
The procedure whereby a new human being is conceived in a glass dish has raised issues that must be faced by investigators and by the public. The debate needs to be informed by known facts of human development...
Features
The Nerve-Growth Factor
This protein plays a key role in the formation of the nervous system. It has also been employed as an "Ariadne's thread" to explore mechanisms of nerve-cell growth and differentiation
Automatic Control by Distributed Intelligence
Microelectronics makes it possible to run an industrial plant with a multitude of "chips" interconnected in a hierarchy extending from the control of one machine to the integration of the entire plant...
The Theory of Knots
A piece of knotted string with its ends joined is a good physical model of an abstract mathematical knot. The theory of knots seeks to analyze the different ways of tracing a knotted curve in space...
A Neolithic Flint Mine
The start of farming in prehistoric Europe increased the demand for flint tools. Excavation at one flint-rich valley in the Netherlands shows how miners dug up flints by the ton more than 5,000 years ago...
Ultracold Neutrons
Neutrons moving so slowly that they cannot penetrate a solid surface can be confined in a metal bottle. By storing them for long intervals it may be possible to measure fundamental properties of the neutron...
The History of the Atlantic
The ocean is 165 million years old. Its growth and the topography of its bottom are explained by plate-tectonic theory, deep probes of the bottom and measurements of heat flow and magnetism...
The Year without a Summer
In 1816 in New England it snowed in June, and then killing frosts continued through August. The cause was the explosion ofa volcano in Indonesia. The economic and social consequences are instructive...
Departments
50 and 100 Years Ago, June 1979
Science and the Citizen, June 1979
- Letters
Letters to the Editors, June 1979
- Recommended
Books, June 1979
- Mathematical Recreation
Mathematical Games, June 1979
- Amateur Scientist
The Amateur Scientist, June 1979
- Departments
The Authors, June 1979
Bibliography, June 1979
