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The Choice of Voting Systems

Any voting system can lead to paradoxical results where losers are preferred to winners and winners become losers. In certain situations, however, some voting systems are better than others

By Richard G. Niemi and William H. Riker

An Electron-Hole Liquid

Inside a semiconductor crystal float glowing droplets of a liquid composed entirely of electrons and "holes". The properties of this quantum-mechanical fluid are revealed by the radiation it emits

By Gordon A. Thomas

The Purple Membrane of Salt-loving Bacteria

The color is that of rhodopsin, the "visual purple" of the animal eye. In halobacteria rhodopsin serves as the pigment of a newly discovered photosynthetic mechanism that converts light into chemical energy

By Walther Stoeckenius

Navigation between the Planets

Advances in tracking and computing methods are such that when the first of the two Viking spacecraft reaches Mars late in June, its position should be known to within 50 kilometers

By William G. Melbourne

17,000 Years of Greek Prehistory

Excavations at a site in the Peloponnesus show evidence of human habitation from the Ice Age through Neolithic times. They reveal the basic economic foundation of the Classical Greek civilization

By Thomas W. Jacobsen

Center-Pivot Irrigation

From the air over the U.S. high plains one can now see thousands of large circular fields. They are irrigated by a system in which water is applied from a central well by a novel rotating machine

By William E. Splinter

Historical Supernovas

Early records indicate that seven of these huge stellar explosions were seen over a period of 1,500 years. At the recorded positions of the new stars remnants of the explosions can be observed today

By David H. Clark and F. Richard Stephenson

Future Performance in Footracing

Running records are still far below human physiological limits. The restraints on performance are psychological: good runners do not work as hard once they have set a record or won a medal

By Harry Jay Carr, Henry W. Ryder and Paul Herget


  • 50 and 100 Years Ago, June 1976

  • Science and the Citizen, June 1976

  • Letters

    Letters to the Editors, June 1976

  • Recommended

    Books, June 1976

  • Mathematical Recreation

    Mathematical Games, June 1976

  • Departments

    The Authors, June 1976

  • Bibliography, June 1976

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