Scientific American Magazine

Mathematical models help to reveal how the AIDS virus infects individuals and communities. They sometimes produce results that upset simple intuition

This previously elusive and obscure chemical is proving to be of vital physiological significance. Nitric oxide may be the first of a novel class of neurotransmitters

These fluorescent clouds of gas represent the last gasp of dying, sunlike stars. They are helping astronomers understand stellar evolution and even the ultimate fate of the universe

Investigating how the visual system compensates for gaps in perception is helping researchers to elucidate how the brain processes images

This marriage of optics and microelectronics has already produced useful lenses one fortieth the thickness of this page and arrays of 10,000 telescopes each the diameter of a human hair

An avian chorus still heralds the beginning of spring in North America, but the number of singers has declined sharply of late. The trend will be difficult to reverse

At 32, Werner Heisenberg was one of the youngest scientists to receive the Nobel Prize. Ambition and fierce competitiveness inspired him to formulate one of the best-known principles of science

Nucleic acids and proteins trapped in ancient mummies and still more ancient bones can serve as time capsules of history. Molecular biologists are beginning to unlock their secrets.