How Many Species Inhabit the Earth?
The sad truth is that no one knows. The answer is relevant to efforts to conserve biological diversity and could illuminate crucial questions about evolution and management of the environment...
Features
Quantum Cryptography
For ages, mathematicians have searched for a system that would allow two people to exchange messages in absolute secrecy. Quantum mechanics has now joined forces with cryptology to achieve a major step in that direction...
Mountain Sickness
The varied and subtle symptoms of this potentially lethal disorder humble many who scale the summits. But the problem is often preventable
Histones as Regulators of Genes
Histones were once dismissed as little more than packing material for nuclear DNA. In fact, these proteins can both repress and facilitate activation of many genes
Singing Caterpillars, Ants and Symbiosis
With siren songs and chemical lures, some butterfly caterpillars attract ants to serve as their guardians. Those same ants are usually involved in symbioses with other insects and plants as well...
Diamond Film Semiconductors
Thin sheets of diamond, grown {rom a low-pressure gas and doped with impurities, may serve as the basis for a new generation of electronic devices
Scavenging and Human Evolution
Although meat eating helped to shape the evolution of human brains, behavior and toolmaking, our early ancestors seem to have been better scavengers than hunters
Teaching Real Science
Educators are planning a revolution in science teaching. They face an uphill struggle.
Departments
- Letters
Letters to the Editors, October 1992
- Recommended
Book Reviews, October 1992
- 50, 100 & 150 Years Ago
50 and 100 Years Ago: October 1992
- Profile
Illuminator of the Stars
- Mathematical Recreation
Murder at Ghastleigh Grange
- Science and the Citizen
The Edge of Chaos
The Best Little Yard Sale in New Mexico
Lying by the Book
Musseling In
Smart Wheels
Formula for Diabetes?
A Matter of Timing
The Cosmic Microwave Mirage?
Orphan Isotopes
- Departments
The Business of Education
Agenda 21: Sustainable Development
- Technology and Business
Storage Space
Different Strokes
Fine Grain
Billions of Buckytubes
Diagnosis by DNA
