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Marihuana

There is considerable evidence that the drug a comparatively mild intoxicant. Its current notoriety raises interesting questions about the motivation of those who use it and those who seek to punish them

By Lester Grinspoon

New Methods for Approaching Absolute Zero

Low-temperature physicists have recently devised three different experimental procedures capable of lowering the temperature range accessible for research to within millidegrees of absolute zero

By O. V. Lounasmaa

The Rise and Fall of Arabia Felix

The Semitic kingdoms of southern Arabia waxed rich during the first millennium B.C. by controlling the trade in frankincense and myrrh. Why they waned a few centuries later is a question still under study

By Gus W. Van Beek

The Mechanism of Photosynthesis

Light of two wavelengths is required to activate two photochemical systems. Together they provide the electrons, protons and enery-rich molecules needed to convert carbon dioxide and water into food

By R. P. Levine

Dermatoglyphics

Fingerprints and the similar ridges on the palm of the hand and the sole of the foot have more uses than identification: they are also of value in anthropology, medicine and genetics

By L. S. Penrose

Measuring Earth Strains by Laser

Large interferometers operating with laser beams make it possible to detect tiny distortions of the earth's crust with unprecedented sensitivity. One of these laser strain meters is 1,020 meters long

By Victor Vali

How an Instinct is Learned

A study of the feeding behavior of sea gull chicks indicates that an instinct is not fully developed at birth. Its normal development is strongly affected by the chick's experience

By Jack P. Hailman

The Peculiar Distribution of First Digits

In numbers that appear in tables of constants, lists of street addresses and similar tabulations the first digit of the number is 1 almost three times more often than one would expect. Why?

By Ralph A. Raimi

Departments

  • 50 and 100 Years Ago: December 1969

  • Science and the Citizen: December 1969

  • Books

  • Letters

    Letters to the Editors, December 1969

  • Mathematical Recreation

    Mathematical Games

  • Amateur Scientist

    The Amateur Scientist

  • Departments

    The Authors

  • Annual Index

  • Bibliography

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December 1969

See the World from a Different Perspective

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