Features

• The Case of the Pilfered Planet

  Did the British steal Neptune?

  William Sheehan, Nicholas Kollerstrom and Craig B. Waff   | December 1, 2004  |

• The Brain's Own Marijuana

  Research into natural chemicals that mimic marijuana's effects in the brain could help to explain--and suggest treatments for--pain, anxiety, eating disorders, phobias and other conditions

  Roger A. Nicoll and Bradley N. Alger   | December 1, 2004  | 3

• The Dinosaurs of Arctic Alaska

  Seventy-five million to 70 million years ago, a group of hardy dinosaurs thrived in the harsh climate of what is now northern Alaska

  Anthony R. Fiorillo   | December 1, 2004  |

• Optics and Realism in Renaissance Art

  A much publicized assertion holds that 15th-century painters achieved a new level of realism with the help of lenses and mirrors. But recent findings cast doubt on that idea

  David G. Stork   | December 1, 2004  |

• Are Viruses Alive?

  Although viruses challenge our concept of what "living" means, they are vital members of the web of life

  Luis P. Villarreal   | December 1, 2004  | 2

• The 2004 Scientific American 50 Award

  Our third annual salute to the people and institutions brightening our future recognizes accomplishments in stem cells, nanocomputers, mini fuel cells and more

  The Editors   | December 1, 2004  |