Even thousands of years ago, written messages were sent over long distances. Unfortunately, the concept of including your return address hadn't been invented yet, so we don't know where ancient letters came from (and which cultures were talking)...until now. Professor Yuval Goren, an archaeologist at Israel's Tel Aviv University, has modified a standard portable X-ray scanner to determine the secret origins of ancient letters. At its most basic, the scanner can determine the soil and clay composition of any artifact. Since different regions at different times have different mixes of soil and clay, this allows Professor Goren to place the...