Nanotechnology is a fledgling science that will take years to fully develop, which is not unusual in the world of discoveries and inventions. Theories and knowledge we take for granted today — from Newton’s law of gravity to the discovery of DNA — took centuries to realize. The timeline at right shows just how far science has come, highlighting some of the most noteworthy achievements in chemistry and physics. How soon will nanotechnology impact society at large? That’s hard to say, but scientists predict that it may become the distinctive technology of the 21st century.