The Olympic Games have their origins in antiquity, but their modern revival has also been going on longer than any of us has been here. Even the fifth Summer Olympics, which took place in Stockholm in 1912, has passed out of living memory. But thanks to the technology of the twenty-first century, we can call up surprisingly crisp footage of its competitions any time we like, much as we’re doing with that of the currently ongoing thirty-third Summer Olympics in Paris. One especially fascinating use of these resources...