The solution to the riddle of Stonehenge could be music, proposes a California researcher. It's a little abstract: Steven Waller says the people who laid out the mysterious monuments may have been inspired by their perception of sound, reports the BBC. If you put two people playing flutes in a field, their sound waves would interfere with each other, creating an "auditory illusion" of loud and quiet zones for a listener who was circling the musicians, says Waller.
"If you could look at it from an overhead view, it would look like the spokes of a wheel," he explains. "And, as you walk around the circle, every time you come to one of these sound-wave cancellation points, it feels like there is this massive invisible object in front of you. Put all this 'vision in your mind' together and it forms a Stonehenge-like structure." The mysteriousness of sound waves would have been almost magical in Neolithic times, adds the Guardian, which offers an audio file of the flute example. (Read more Stonehenge stories.)