“The distinction between micro- and macroinventions is useful because, as historians of technology emphasize, the word first is hazardous in this literature. . Many technological breakthroughs had a history that began before the event generally regarded as “the invention,” and almost all macroinventions required subsequent improvements to make them operational. Yet in a large number of cases, one or two identifiable events were crucial. Without such breakthroughs technological progress would eventually fizzle out.”