Eli Raz, an Israeli geologist, found himself in something of a hole, and a rather deep one. He had stopped his car on a desert highway near his home by the Dead Sea to inspect some rock formations. As he was walking a few hundred meters from the road, he felt a rumble and heard a whooshing sound. Then he started falling. When he landed, he found himself at the bottom of a deep sinkhole. The sides were sheer drop-offs and Raz couldn't climb out. Eight hours later, a policeman noticed the hole and found him there. Few, if any, are more qualified to understand such sinkholes: For decades, Raz has studied the rocks and river systems that flow into the Dead Sea.