MOUNT SODOM, ISRAEL — Israeli researchers said Thursday they have surveyed what they now believe to be the world’s longest salt cave, a network of twisting passageways at the southern tip of the Dead Sea. A recently completed survey of the Malham Cave determined the labyrinthine cavern stretches more than 6 miles in length. That puts it well ahead of Iran’s Namakdan Cave, previously thought to be the longest salt cave. **SNIP** The Malham Cave’s main outlet yawns not far from a salt pillar named “Lot’s wife,” after the biblical character who was petrified for looking back at the destruction...