Past Forward: Tragedy Spurred the First Effective Land-Mine Detector: Before World War II, Soldiers Hunted for Land Mines with Pointy Sticks

Land mines have been around in one form or another for more than a thousand years. By now, you'd think a simple and safe way of locating and removing the devices would've been engineered. But that's not the case. In fact, up until World War II, the most common method for finding the explosives was to prod the ground with a pointed stick or bayonet. The hockey-puck-size devices were buried about 15 centimeters below the ground. When someone stepped on the ground above or near the mine, their weight triggered a pressure sensor and caused the device to explode. So mine clearing was nearly as dangerous as just walking through a minefield unawares.