Let's begin with your great-great-great-etc.-grandparents. I'm talking eight or nine of those "greats," meaning your ancestors living around the first decades of the 1800s. Here is what I want you to consider: Those guys never raced across the sky, 5 miles above the planet, at 400 miles an hour, in a chair, in a pressurized tube. They didn't carry around little boxes in their pockets that gave them instant access to every corner of the planet, as...
