The decline of the birthrate in the industrialized countries is both a cause and a consequence of changes in marriage and the famliy. How will nations respond to a long-term decrease in population?...
By Charles F. Westoff
At certain energies protons and neutrons in nuclei form clusters moving in simple orbits with respect to each other. These nuclear molecules constitute a new kind of nuclear structure and dynamics...
By D. Allan Bromley
Fuel-Cell Power Plants
These devices that generate electricity directly from fuel without emitting pollutants are currently being scaled up to determine if they can be economic for electric utilities
By Arnold P. Fickett
Hemoglobin Structure and Respiratory Transport
Hemoglobin carries oxygen from the lungs to the tissues and helps to transport carbon dioxide back to the lungs. It fulfills this dual role by clicking back and forth between two alternative structures...
By M. F. Perutz
Animal Eyes with Mirror Optics
Some man-made mirrors now have reflecting surfaces made up of multiple thin layers instead of metal. It turns out that several kinds of animals have eyes based on the same system
By Michael F. Land
The Razed Temple of Akhenaten
The Pharaoh who wanted Egypt to worship one god erected imposing monuments at Karnak. His successors took great pains to level them. What they were like is now being pieced together from the fragments...
By Donald B. Redford
Fast Running Tracks
On a springy new indoor track at Harvard University runners can run faster than they can on standard tracks. The design of the track was arrived at through a close analysis of the mechanics of human running...
By Peter R. Greene and Thomas A. McMahon
These spectacular clouds within our galaxy are sites of star formation. Radio spectroscopy indicates, among other things, that the clouds belong to much larger systems of gas and dust