Sexually Transmitted Diseases in the AIDS Era
Gonorrhea, syphilis and other infections still exact a terrible toll. Social conditions help to fuel the new epidemics—and only a combination of social and health programs can defeat them...
Features
The Number of Families of Matter
How experiments at CERN and SLAC, using electron-positron collisions, showed that there are only three families of fundamental particles in the universe
The Physiology of Perception
The brain transforms sensory messages into conscious perceptions almost instantly. Chaotic, collective activity involving millions of neurons seems essential for such rapid recognition
X-ray Microscopes
Recent progress has yielded "soft" X-ray instruments whose resolution is 10 times better than that of optical microscopes. They offer a new way to observe minute structures and to perform chemical analysis...
The Echidna
This egg-laying mammal, also called the spiny anteater, has lived in relative obscurity in the Australian bush. Now secrets of its natural history and reproductive behavior are being explored...
Computers and Architecture
Advanced modeling and rendering algorithms allow designers and clients to walk through buildings long before construction
The Acoustics of the Harpsichord
A complex interplay of string, wood, air and the human ear produces the swirling sound of the harpsichord
In the Beginning…
Scientists are having a hard time agreeing on when, where and—most important—how life first emerged on the earth
Departments
50 and 100 Years Ago: February 1991
Iraq's Nuclear Threat
The A Team
Postal Mortem
Disposable Astronomy
Charting a more cautious path to space
Hubble bags a great white
Safe Bytes
Superconducting transistors show their speed
Nuclear Numbers
Life in the Blood
Changing Mission
An acoustic sensor spies on insects
Hole or Doughnut
Reach Out
- Letters
Errata
Letters to the Editors, February 1991
- Recommended
Books, February 1991
- Mathematical Recreation
Mathematical Recreations, February 1991
- Departments
The Analytical Economist: Don't write off Marx
Essay, February 1991
