Magazine

September-October 2000

Current Issue

September-October 2000

Volume: 88 Number: 5

Ideas about the proton have evolved considerably since Rutherford first identified this subatomic particle in the second decade of the 20th century. In "The Search for QCD Exotics," Alex R. Dzierba, Curtis A. Meyer and Eric S. Swanson explain that theorists realized in the 1960s that the proton contains three elementary subunits—dubbed quarks. More recently, physicists have come to appreciate that quarks have "color" and that the proton encompasses an intertwined web of particles, some of which are made of nothing more than the force that holds matter together. (Illustration by Tom Dunne.)

In This Issue

  • Agriculture
  • Art
  • Astronomy
  • Biology
  • Communications
  • Economics
  • Engineering
  • Environment
  • Evolution
  • Mathematics
  • Medicine
  • Physics
  • Psychology
  • Technology

A New Urban Ecology

James Paul Collins, Ann Kinzig, Nancy Grimm, William Fagan, Diane Hope, Jianguo Wu, Elizabeth Borer

Environment

Modeling human communities as integral parts of ecosystems poses special problems for the development and testing of ecological theory

The Search for QCD Exotics

Alex Dzierba, Curtis Meyer, Eric Swanson

Physics

Particles predicted by the theory of quantum chromodynamics help explain why the fundamental building blocks of matter are impossible to isolate

Pollination of Cacti in the Sonoran Desert

Theodore Fleming

Environment Evolution

When closely related species vie for scarce resources, necessity is the mother of some pretty unusual evolutionary inventions

Andrew Ellicott Douglass and the Big Trees

Donald McGraw

Biology Environment

The Giant Sequoia was fundamental to the development of the science of dendrochronology—tree-ring dating

Scientists' Nightstand