This yearbook presents and interprets trends and discoveries in a review of the science year. There are feature articles on: science fiction; the Voyager space probes; space tethers; architectural structure; the National Aquarium in Baltimore; the social life of dolphins; spiders; life without water; the Yellowstone fires; remote sensing and archaeology; "smart" materials; the radicals of chemistry; the physics of thrill rides; technology in the theatre; serendipity and scientific discovery. The Britannica science update section includes recent revisions of the Macropaedia articles on mollusks and principles of physical science, and a survey of developments in 20 branches of science, alphabetically arranged.