A Shortcut Through Time

George Johnson is a science writer for the New York Times. He is a former Alicia Patterson Fellow, a finalist for the prestigious Aventis Prize, and a recipient of the Science Journalism Award from the American Association for the Advancement of Science.The newest Pentium chip powering PCs and laptops contains 40 million electronic switches packed onto a piece of silicon about the size of a thumbnail. Several years from now, if this incredible shrinking continues, a single chip will hold a bill