You might be surprised to find out that a medieval superstition remains a viable business to this day, but it's true. Dowsers, also known as water witches, claim to be able to find water flowing under ground simply by holding sticks and walking around a property. They charge a fee to tell you where to dig wells.

Dowsers have been around for millennia, and you can still hire them today—they even have a professional society in the US (and no, we're not going to link it). What can explain this persistence?

As you'll see in our video, they're actually preying on ignorance. If there's any ground water present at all, geology dictates that it's going to be hard to miss if you dig a well. As a result, dowsers can tell you to dig your well just about anywhere, and you can be assured that the service will "work," in that you'll find some water. As our own Scott Johnson says, it's like hiring someone to tell you which window to open to find some air.

Amazingly, there's actually some published literature on tests of dowsers. If you want to see the results, just watch the video.