The Modulation of Laser Light
The great potential of the laser for use in long-distance communication systems has been brought closer to realization by the development of large-bandwidth, low-power modulators
Features
A Stone Age Campsite at the Gateway to America
Onion Portage in Alaska is an unusual Arctic archaeological site. It provides a record of human habitation going back at least 8,500 years, when its occupants were not far removed from their forebears in Asia...
Stars in Contact
About one star in 1,000 is in actuality a pair of stars so close together that their atmospheres exchange material. These contact binaries have something to tell us about the evolution of stars...
Standards of Measurement
The goal is to define standards of length, mass, time and temperature that are both precise and reproducible. Of the four only mass still lacks a referent in nature
The Brain of Birds
Since birds have a smaller cerebral cortex than mammals, are they less intelligent than mammals? Recent work suggests that they may simply use other parts of the brain to effect intelligent behavior...
The Discovery of DNA
In 1869 Friedrich Miescher found a substance in white blood cells that he called "nuclein." Cell biologists saw that it was a constituent of chromosomes and hence must play a major role in heredity...
Polishing
Is polishing simply fine-scale abrasion or is it more akin to melting? Recent findings suggest that neither of these two old rival hypotheses is entirely correct
Plants without Cellulose
It was once believed that cellulose was the structural material in the cell walls of all green plants. Now it appears that other substances are employed for this purpose in certain marine algae...
Departments
50 and 100 Years Ago: June 1968
Science and the Citizen: June 1968
- Letters
Letters to the Editors, June 1968
- Recommended
Books
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist
- Departments
The Authors
Bibliography
