Thermal Pollution and Aquatic Life
The increasing use of river and lake waters for industrial cooling presents a real threat to fish and other organisms. To avoid an ecological crisis new ways must be found to get rid of waste heat...
Features
Superplastic Metals
A new approach to the processing of metals makes it possible to form them by methods usually reserved for glass and plastics. This processing gives the metals a distinctive microstructure...
Phases in Cell Differentiation
By cultivating embryonic tissue in the laboratory one can study the specialization of cells in the mammalian pancreas. There seem to be three regulatory phases, each leading to a new stage of differentiation...
Continental Drift and Evolution
The breakup of ancient supercontinents would have had major effects on the evolution of living organisms. Does it explain the difference in the diversification of reptiles and mammals?
Brownian Motion and Potential Theory
The discovery that these two apparently unrelated branches of physics are in some sense mathematically equivalent has led to a new subject known as probabilistic potential theory
The Atmospheres of Mars and Venus
Distance from the sun can only partly explain why the atmospheres of these two planets are so different. If life had not appeared on the earth, its atmosphere might resemble that of one or the other...
Plague Toxin
The bacillus that caused the "Black Death" manufactures a protein that is lethal to some animals and harmless to others. How does this substance exert its effect on the molecular machinery of the cell?...
The First Electron Tube
In 1904 John Ambrose Fleming wrote Guglielmo Marconi: "I have been receiving signals on an aerial with nothing but a mirror galvanometer and my device." The device was the original thermionic vacuum diode...
Departments
50 and 100 Years Ago: March 1969
Science and the Citizen: March 1969
- Letters
Letters to the Editors, March 1969
- Recommended
Books
- Mathematical Recreation
Mathematical Games
- Amateur Scientist
The Amateur Scientist
- Departments
The Authors
Bibliography
