Ever since I was a kid, I've been intrigued by gestalt pictures. These intriguing pictures contain two images, but the viewer can see only one of them at a time; as one comes to the foreground, the other recedes into the background. In one famous picture I can see either two faces or a candlestick. In another one, I can see either a young woman or an older one.
When you register for a driver’s license in the United States you are asked if you’d like to be an organ donor. It’s an “opt-in” question, and only about 40 percent of people choose that option. In Spain, Portugal, and Austria, you’re considered an organ donor unless you opt out. In those countries about 99 percent of the people are registered as organ donors, and there are a higher number of transplants as a result (ProPublica, July 27).