When we think of large monumental structures built by early societies, an Egyptian pyramid probably comes to mind. but there are some even earlier structures in the British shales also worth discussion. And besides the well known circle of massive stones of stone henge, which don’t get me wrong is remarkable enough, well, other impressive neolithic structures are found there too. Oh yes, we are talking about the neolithic period here, also called the new stone age, which was the time before stone tools began to be replaced by tools made of bronze and other metals. It was about 5000 years ago, even before the first Egyptian pyramid, that some amazing neolithic monuments, tombs, were recked at vary size around Ireland, great Britain and costal islands nearby.
I am referring in particular structures that in some cases look like ordinary natural hills, but were definitely built by human, well organized communities of humans, to enclose a chamber, or room within stone walls. And sometimes a high, cleverly designed celling of overlapping stones. These structures are called passage graves. Because the inner chamber, sometimes several chambers in fact, could only be entered from the outside through a narrow passage way.
Excuse me, professor, but you said passage GRAVES. Were these just monuments to honor the dead buried there, or, were they designed to somehow used by the living?
Ah yes. Good question Michael. Besides being built as tombs, some of these passage graves were definitely what we might called, astronomical calendars. with chambers that were flooded with sunlight on certain special days of the year, which must have seen raculars and inspired of great deal of religious wonder.
But research indicates that not just light, but also the physics of sound helped in hand in these religious experiences.
Well, first echos. When a religious leader started chanting with echos bouncing off a stone walls over and over again, it must have seen a whole chorus of other voices. Spirits or gods maybe, joining in. But even more intriguing, is what physicists called, standing waves.
Basically, the phenomenon of standing waves occurs when sound waves of the same frequency reflects off the walls and meet from opposite directions. So the volume seems to alternate between very loud and very soft. You can stand quite near a man singing in a loud voice, and hardly hear him, yet, step a little further away and his voice is almost deafening. As you move around the chamber, the volume of the sound goes way up and way down, depending on where you are in these standing waves.
And oftenly acoustics make it hard to identify where sounds are coming from. It is if this powerful voice is speaking to you, or chanting from inside your own head. This had to engender a powerful sense of all in neolithic worshippers.
And another bit of physic it applies here, is something called resonance. I am not a physicist, but, well, I imagine you’ve all blown air over the top of an empty bottle and heard of the sound it makes. And you’ve probably noticed that depending on its size, each empty bottle plays one particular musical note. Or as a physicist might put it, each bottle resonates, at a particular frequency. Well, that’s true of these chambers too. If you make a constant noice inside the chamber, maybe by steadily beating a drum at a certain rate, a particular frequency of sound will resonate, will ring out intensely, depending on the size of the chamber. In some of the larger chamber though, this intensify sound might be too deep for us to hear, we can feel it, with mysterious agitated by it, but it is not a sound our ear can hear.
The psychological effects of all these extraordinary sounds can be profound. Especially when they seem so disconnected from the human doing the drumming or chanting. And there can be observable physical effects on people too. In fact, the sounds can cause headaches, feelings of dizziness, increase heartrate, that sort of things you see? Anyway. What was experienced in one of these passage graves, clearly can be far more intense than everyday reality outside, which make them very special places.
But back to your question Michael, as to whether these graves were designed to be used by the living, well, certainly with regards to astronomical or calendar functions that seems pretty obvious, and I wanna go into more detail on that now.