A group of archaeologists studying the renowned Stonehenge megalithic monument suggest that the entire structure was erected as an attempt to replicate a sound-based illusion. This is by far one of the most daring proposals on why one of the world's most mysterious monuments was built.
Many have suggested that the structure is actually a large calendar, meant to help people of the time monitor the motions of celestial bodies. Others proposed that Stonehenge was in fact a place of worship, similar to a church or mosque today.
What a group of scientists is currently proposing is that Stonehenge was constructed in such a way that it imitates a type of acoustical illusion encountered when two pipers playing in the field cancel each other's sounds out, at certain points.
This happens due to the way in which sound waves interact. If the two are face to face, separated by a medium distance, then a listener would hear different sounds depending on their position relative to the two players, LiveScience
It could be that the entire monument was built to replicate these experiences, Rock Art Acoustics USA PhD researcher Steven Waller told experts present at the annual meeting of the American Association for the Advancement of Science (AAAS 2012), in Vancouver, British Columbia.
Waller's area of research is called archaeoacoustics, and deals with analyzing the properties of sound at ancient sites. What this implies is analyzing how sounds are muffled, amplified and propagated through various structures.
In the case of Stonehenge, the layout of rocks making up the site's perimeter is responsible for muffling and blocking the sound waves produced in the middle. In effect, the builders managed to reproduce the piper illusion with rocks, instead of sound waves.
Waller admits that the theory is speculative at best, but says that investigations conducted thus far have been able to determine that sounds indeed travel in an unusual manner inside the megalithic structure.
Interestingly, stone circles are called piper stones in Great Britain. Also, one of the old myths surrounding the creation of Stonehenge holds that two pipers sang for maidens on the field, and then turned the latter to stone.
“Nobody has been paying attention to sound. We've been destroying sound. In some of the French [rock art] caves, they've widened the tunnels to build little train tracks to take the tourists back – thereby ruining the acoustics that could have been the whole motivation in the first place,” Waller says.
He hopes that the new proposal will highlight the potential role that acoustics played throughout history, in constructing monuments such as Stonehenge and the three largest Egyptian pyramids.