SCIENTISTS AT THE UNIVERSITY OF CALGARY gave new meaning to the term when they unveiled CAVEman, a computer-generated hologram that can display any combination of 3,000 human body parts (such as teeth or individual layers of skin) in ultrasharp resolution. CAVEman (so named because it lives in a CAVE Automatic Virtual Environment—a virtual reality theater) assumes four dimensions: the usual three for space, plus time, allowing researchers to watch the progression of conditions (such as tumor growth) and track the effects of potential treatments.