Some questions you ask because you want the right answer. Others are valuable because no answer is right; the payoff comes from the range of attempts. Seven years ago, The Atlantic surveyed a group of eminent historians to create a ranked list of the 100 people who had done the most to shape the character of modern America. The panelists agreed easily on the top few names—Lincoln, Washington, Jefferson, in that order—but then began diverging in intriguing ways that reflected not simply their own values but also the varied avenues toward influence in our country. Lewis and Clark, or Henry Ford? Thomas Edison, or Martin Luther King? The result was of course not scientific. But the exercise of asking, comparing, and choosing helped us understand more about what these historical figures had done and about the areas in which American society had proved most and least open to the changes wrought by talented, determined men and women.
Now we turn to technology. The Atlantic recently assembled a panel of 12 scientists, entrepreneurs, engineers, historians of technology, and others to assess the innovations that have done the most to shape the nature of modern life. The main rule for this exercise was that the innovations should have come after widespread use of the wheel began, perhaps 6,000 years ago. That ruled out fire, which our forebears began to employ several hundred thousand years earlier. We asked each panelist to make 25 selections and to rank them, despite the impossibility of fairly comparing, say, the atomic bomb and the plow. (As it happens, both of these made it to our final list: the discovery and application of nuclear fission, which led to both the atomic bomb and nuclear-power plants, was No. 21 of the top 50, ahead of the moldboard plow, which greatly expanded the range of land that farmers could till, at No. 30.) We also invited panelists to add explanations of their choices, and I followed up with several of them and with other experts in interviews.