One panelist ranked his choices not by importance but by date of invention, oldest (cement) to newest (GPS satellites). Some emphasized the importance not of specific breakthroughs but of broad categories of achievement. For instance, Joel Mokyr, an economic historian at Northwestern, nominated in his top 10 “modularity.” By that he meant the refinements in industrial processes that allowed high-volume output of functionally identical parts. This enabled mass production and the Henry Ford–style assembly line (49 on The Atlantic’s list), and the profound shift from handmade to volume-produced versions of everything. Modularity didn’t make it onto our final list; the adoption of standardized shipping containers, which extended the same logic in a different realm, just missed the cut.

In short, these scientists and creative types decided to answer the question they wanted us to ask, rather than the exact one we posed. We have new sympathy for people attempting to manage universities and R&D labs. But in the end we had enough comparable and overlapping suggestions, from enough people, with enough spelled-out explanations, and enough force of experience and insight behind them, to be comfortable presenting The Atlantic’s survey of humanity’s 50 most important technical breakthroughs since the wheel. We converted all the responses into values we could enter on a spreadsheet; we weighted, as reasonably as we could, the intensity and breadth of support; we watched the combined rankings go up and down as each new response arrived; and we came up with the final ranking you see here.

One aspect of the results will be evident as soon as you start looking through them: the debatability of the choices and rankings once you move beyond the first few. For instance, anesthesia (46), which, on its debut in 1846, began to distinguish surgery from torture, barely made the top 50, and that was only because one panelist pushed it hard. If I were doing the ranking, it would be in the top 10, certainly above the personal computer (16 on our final list). In this case the test for me is: Which would I miss more if it didn’t exist? (Our panelist John Doerr, a well-known technology investor, said he worked his way through his own top‑25 list using a similar set of “pairwise comparisons,” asking which technology he would miss more.) I rely on personal computers, but I got along fine before their introduction; I still remember a dental procedure in England when the National Health Service didn’t pay for novocaine.

Less evident from the final list is what I was fascinated to learn from my talks with many of the panelists. That is the diversity of views about the types of historical breakthroughs that matter, with a striking consensus on whether the long trail of innovation recorded here is now nearing its end.