Aza was proud of the design. “At the outset, it looks like a really good invention,” he told me. He believed he was making life easier for everyone. He had been taught that increased speed and efficiency of access were always advances. His invention quickly spread all over the internet. Today, all social media and lots of other sites use a version of infinite scroll. But then Aza watched as the people around him changed. They seemed to be unable to pull themselves away from their devices, flicking through and through and through, thanks in part to the code he had designed. He found himself infinitely scrolling through what he often realized afterward was crap, and he wondered if he was making good use of his life.

One day, when he was thirty-two, Aza sat down and did a calculation. At a conservative estimate, infinite scroll makes you spend 50 percent more of your time on sites like Twitter. (For many people, Aza believes, it’s vastly more.) Sticking with this low-ball percentage, Aza wanted to know what it meant, in practice, if billions of people were spending 50 percent more on a string of social-media sites. When he was done, he stared at the sums. Every day, as a direct result of his invention, the combined total of 200,000 more human lifetimes—every moment from birth to death—is now spent scrolling through a screen. These hours would otherwise have been spent on some other activity.