Antisatellite Weapons
Unless some action is taken soon to restrain the further development of such weapons the positive contributions of satellites to international security will be threatened
Features
Pre-Columbian Surface Metallurgy
The metalsmiths of Andean cultures knew how to plate copper with gold or silver and how to treat alloys of copper, gold and silver so that the surface of the metal consisted only of gold...
Mass Extinctions in the Ocean
During brief intervals over the past 700 million years many marine animals and plants have died out. Geologic evidence now suggests that most of the mass extinctions were caused by cooling of the sea...
Transposable Genetic Elements in Maize
The mobile genes Barbara McClintock discovered 40 years ago have since been identified in bacteria, other plants and animals. Several maize elements have now been characterized at the molecular level...
An Atomic Preference between Left and Right
The left- and right-handed versions of an atomic experiment do not always give rise to mirror-symmetric effects. The asymmetry is caused by the weak force between the electrons and the nucleus...
Acoustic and Chemical Signals in the Life Cycle of a Beetle
The subtle interplay of such signals enables the Douglas-fir beetle to attract a mate, to repel intruders and to regulate the density of its population in the great tree of the western forest on which it preys...
The Structure and Evolution of Interstellar Grains
The particles of cosmic dust turn out to have an elaborate core-and-mantle construction. In the organic mantle there is evidence of complex, and even violent, chemical processes
Nuts and Bolts
The notion that a threaded bolt and a matching nut could serve as a fastener dates back only to the 15th century. Today nuts and bolts and ways of making them are still actively evolving...
Departments
50 and 100 Years Ago: June 1984
- Letters
Letters to the Editors, June 1984
- Recommended
Books, June 1984
- Amateur Scientist
The Amateur Scientist, June 1984
- Science and the Citizen
Science and the Citizen, June 1984
- Departments
The Authors, June 1984
Computer Recreations, June 1984
Bibliography, June 1984
