Steel Minimills
At a time in the U.s. when some large steel plants that start with iron ore are being shut down, smaller plants that start with scrap steel and market a limited line of products locally are doing well...
Features
Oceanic Fracture Zones
They complicate the pattern discerned in the theory of plate tectonics by dissecting the edges of the plates that compose the ocean floor. Some of them are the width of an ocean basin
How Receptors Bring Proteins and Particles into Cells
Receptor-mediated endocytosis is a process whereby cells can take up specific large molecules. In most cases a receptor, having delivered its ligand, is recycled to the plasma membrane to bind more ligand...
Turing Machines
At its logical base every digital computer embodies one of these pencil-and-paper devices invented by the British mathematician A. M. Turing. The machines mark off the limits of computability...
Parasites that Change the Behavior of their Host
In doing so they make the host more vulnerable to predation by their next host. Among such parasites are certain thorny-headed worms, which infest pill bugs that are later eaten by songbirds...
The Inflationary Universe
A new theory of cosmology suggests that the observable universe is embedded in a much larger region of space that had an extraordinary growth spurt a fraction of a second after the primordial big bang...
An Indian Hunters' Camp for 20,000 Years
A rock shelter in western Pennsylvania was periodically occupied from about 19,000 B.C. to A.D. 1000. The extreme age of the site bears on the question of when men entered the Western Hemisphere...
Island Epidemics
Epidemics are patterns in time and space that can best be perceived when they are studied in a small, isolated population. An example is provided by a study of a century of measles epidemics in Iceland...
Departments
50 and 100 Years Ago: May 1984
Science and the Citizen, May 1984
- Letters
Letters to the Editors, May 1984
- Recommended
Books, May 1984
- Amateur Scientist
The Amateur Scientist, May 1984
- Departments
The Authors, May 1984
Computer Recreations, May 1984
Bibliography, May 1984
