Magazine
July-August 2001
July-August 2001
Volume: 89 Number: 4
Titanium silicon carbide is a member of a recently discovered class of ceramics with remarkable properties. The compounds discussed by Michel W. Barsoum and Tamer El-Raghy in "The MAX Phases: Unique New Carbide and Nitride Materials" may one day help increase the efficiency of jet engines and industrial chemical processes, among other applications. The stunning colors in this optical micrograph by Patricia Lyons, showing an area 70 micrometers wide, are the result of interference. Much like the rainbow effects produced by an oil slick on water, thin layers of different thicknesses strongly reflect light of different colors. The small patches of color are different crystal grains in the material. The bold streak of yellow-red was caused by a slight scratching of the polished surface.
In This Issue
- Agriculture
- Art
- Astronomy
- Biology
- Chemistry
- Communications
- Computer
- Economics
- Engineering
- Environment
- Ethics
- Evolution
- Mathematics
- Medicine
- Physics
- Policy
- Psychology
- Technology
Iris Recognition
John Daugman
Technology
The colored part of the eye contains delicate patterns that vary randomly from person to person, offering a powerful means of identification
Protostars
Thomas Greene
Astronomy
"Stellar embryology" takes a step forward with the first detailed look at the youngest Sun-like stars
The Nature of Emotions
Robert Plutchik
Psychology
Human emotions have deep evolutionary roots, a fact that may explain their complexity and provide tools for clinical practice
Science and Uncertainty in Habitat Conservation Planning
Laura Watchman, Martha Groom, John Perrine
Environment
A review of 43 habitat conservation plans reveals numerous ways to reduce uncertainty for landowners and imperiled species alike
