Modern humanity has produced astonishing shifts in historic blinks. Here, for example, is one of the most fascinating maps ever produced?"known as an isochronic map?"which shows how far from London a human being could plausibly travel in a given time period in 1914, just over a century ago. The red shaded areas show a journey of five days or less; the pink five to ten days; the yellow ten to twenty days; the green thirty to forty days; all the way up to the darker teal shades which showcase the most remote regions?"reachable only after a trek of at least forty days, nearly a month and a half.