Prehistoric Art Inspired by the 'Supernatural'

Prehistoric art, from cave paintings and canyon petroglyphs to major architectural structures like Stonehenge, may have been inspired by the "supernatural," a new study says.

Humans long ago thought they were experiencing something out of this world, but in actuality they were just being played by a trick in the behavior of sound waves.

"Ancient mythology explained echoes from the mouths of caves as replies from spirits, so our ancestors may have made cave paintings in response to these echoes and their belief that echo spirits inhabited rocky places such as caves or canyons," researcher Steven J. Waller explained in a statement.

Just as light reflection gives an illusion of seeing yourself in a mirror, sound waves also reflect off surfaces in a manner that humankind once thought rocks were talking to them - in their own way.

According to the study, echoes of clapping can sound similar to hoof beats, while multiple echoes within a cavern can blur together into a thunderous sound resembling an animal stampede.

"Many ancient cultures attributed thunder in the sky to 'hoofed thunder gods,' so it makes sense that the reverberation within the caves was interpreted as thunder and inspired paintings of those same hoofed thunder gods on cave walls," Waller said. "This theory is supported by acoustic measurements, which show statistically significant correspondence between the rock art sites and locations with the strongest sound reflection."

Waller tested the theory by considering the circular formation of the megalithic rocks that make up England's famous Stonehenge site. When two flutes were played at the same time, they cancelled each other out in a way that blindfolded subjects imagined a giant ring of rocks, or "pillars," casting acoustic shadows.

"My theory that musical interference patterns served as blueprints for megalithic stone circles - many of which are called Pipers' Stones - is supported by ancient legends of two magic pipers who enticed maidens to dance in a circle and turned them all into stones," he added.

The research, to be presented at the Meeting of the Acoustical Society of America held Oct. 27-31, shows that sound has a way of bolstering people's imagination to help them create works of art.