The other day I finally went on a long-overdue walk in my neighborhood. The sun was shining, the birds chirping, I passed two fishermen in their boat… I took a deep breath and was really enjoying myself, thinking that I need to do this more often, when a big diesel truck drove into the street I was going to walk up. By the time I passed the truck, the driver had gotten out and was fixing something on a car next to it, but the big truck was still running. I kept walking for about ten minutes and finally turned around to walk back home. The loud diesel truck was still running. I looked for the...