The Gas Centrifuge
This machine separates the isotopes of uranium by spinning a gaseous uranium compound. It is expected to play a large role in the Carter Administration's effort to limit the proliferation of nuclear weapons
Features
Stellar Winds
Stars of various sizes and types are observed to eject matter into space in a slow, steady stream. A number of mechanisms may be responsible for this surprisingly common phenomenon
The Hominids of East Turkana
This region on the shore of Lake Turkana in northeastern Kenya is a treasure trove of fossils of early members of the genus Homo and their close relatives dating back 1.5 million years and more
The Tomato
The esculent Lycopersicon esculentum, long thought to be poisonous, has become a major U.S. food crop and source of vitamins and minerals, thanks largely to genetic modification and new production technology
Negative Absolute Temperatures
No substance can be cooled below absolute zero, but some physical systems can have a negative temperature on an absolute scale. Such temperatures are not colder than zero but are hotter than infinity
The Thermostat of Vertebrate Animals
The hypothalamus, a structure at the base of the brain, monitors body temperature in a wide variety of animals and maintains it at an optimal level by controlling thermoregulatory mechanisms
The Tektite Problem
Did these peculiar bits of glass originate on the earth or on the moon, in volcanic activity or in meteorite impact? The evidence is conflicting and the most reasonable answer is a surprising one
Organisms that Capture Currents
A variety of species, from marine sponges to prairie dogs, have harnessed aerodynamic and hydrodynamic forces to increase the flow of air or water through themselves or their abodes
Departments
50 and 100 Years Ago, August 1978
Science and the Citizen, August 1978
- Letters
Letters to the Editors, August 1978
- Recommended
Books, August 1978
- Mathematical Recreation
Mathematical Games, August 1978
- Amateur Scientist
The Amateur Scientist, August 1978
- Departments
The Authors, August 1978
Bibliography, August 1978
