The Geography of U.S. Presidential Elections
Enduring geographic cleavages divide the electorate. They weigh heavily in the Electoral College system and demand that a winning candidate build a geographic coalition
Volume 259, Issue 1
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Features
Gravitational Lenses
These cosmic flukes offer a unique window on the secrets of the universe. Systematic searches now under way are designed to realize the scientific promise of the objects
Hormones that Stimulate the Growth of Blood Cells
Each hemopoietin regulates the production of a specific set of blood cells. Now made by recombinant-DNA methods, these hormones promise to transform the practice of medicine
The Supercontinent Cycle
Several times in earth history the continents have joined to form one body, which later broke apart. The process seems to be cyclic; it may shape geology and climate and thereby influence biological evolution
Randomness in Arithmetic
It is impossible to prove whether each member of a family of algebraic equations has a finite or an infinite number of solutions: the answers vary randomly and therefore elude mathematical reasoning
Capacitors
They are the electronic guardians of integrated circuits. Innovative manufacturing, materials and design have enabled a 200-year-old device to keep pace with silicon technology
How the Human Eye Focuses
As people age, their ability to focus on nearby objects gradually declines. Several probable causes have been identified, including changes in the eye's geometry and biochemistry
The Chaco Canyon Community
This ancient Anasazi site contains the ruins of nine multistory dwellings connected to the outside world by an elaborate system of roads. Why were they built and who lived in them?