Why America's Bridges are Crumbling
Inadequate maintenance has piled up a repair bill that will take decades to pay off. Indeed, the scope of the problem is only now becoming clear
Features
Black Holes and the Centrifugal Force Paradox
An object orbiting close to a black hole feels a centrifugal force pushing inward rather than outward. This paradoxical effect has important implications for astrophysics
Teaching the Immune System to Fight Cancer
Certain molecules on tumors can serve as targets for attack by cells of the immune system. These tumor-rejection antigens may provide a basis for precisely targeted anticancer therapy...
Flat-Panel Displays
Recent advances in microelectronics and liquid crystals make possible video screens that can be hung on a wall or worn on a wrist
How Parasitic Wasps Find their Hosts
Besides recognizing odors from their caterpillar hosts, wasps also learn to identify compounds released by the plant on which the caterpillars feed
Ice Age Lamps
The invention of fat-burning lamps toward the end of the Ice Age helped to transform European culture. It coincided with several other major technological advances
Flooded Forests of the Amazon
Parts of the vast rain forest are as much aquatic as terrestrial ecosystems. Unique adaptations allow creatures to thrive in these inundated woods
DNA's New Twists
The known rules of genetics.....
Departments
- Letters
Erratum
Letters to the Editors, March 1993
- Recommended
Book Review--The End of Biological History?
- 50, 100 & 150 Years Ago
50 and 100 Years Ago: Can Medicine Hold Off a Postwar Epidemic?
- Profile
Stubbornly Ahead of his Time
- Amateur Scientist
Flight-Testing Fruit Flies
- Science and the Citizen
Antarctic Meltdown
Are Scientists Too Messy for Antarctica?
Lethal Cascade
Noah's Freezer
Young Suns
Quark Quest
Preventing the Preventable
- Departments
More Profitable to Give than to Receive?
Inheritance of Acquired Characteristics
- Technology and Business
Back to Basics
No Snake Oil Here
High on Gravity
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