If your papa was actually a rolling stone, your mama could have kept track of him. That’s because his travel distance and travel time would be predictable! In fact, you and mama could’ve used basic math skills to find him. He’d have been thrilled. As it turns out, the same principle used to find your daddy also defines the plume of his cigarette smoke, as well as river systems, migrating bison, the veins in your body, and the [...]