"We can't travel back in time, but we can piece together the clues that the past has left us. In the new series of Unearthing Mysteries, Aubrey Manning attempts to uncover the answers behind four archaeological mysteries. In the first programme he joins the experts who have been examining the extraordinary sounds made by Britainís megalithic sites. Producer Pam Rutherford went along to record the investigation.
Saturday 30th September
"Delay due to weather" - these are the words that greet me and the presenter Aubrey Manning as we arrive at Edinburgh airport. We are hoping to go to Orkney to visit Maeshowe, one of the finest examples of a Neolithic passage grave (burial chamber) in northern Europe and examine its strange acoustic properties. One archaeologist David Keating is flying with us and the other, Aaron Watson, is already driving a car the 1000 miles or so from Reading to Orkney with a boot-load of specially-made speakers, amps, drums, oscilloscopes etc.
After a few hours we are told to board the plane and overhear someone in the queue saying the pilot is Orcadian - good, extra incentive for him to get home. As we sit down he announces that we are "just going to go up and have a look around". We arrive, safely, only an hour late. The drive through Orkney is beautiful and we reach our hotel having driven through weather that changes in front of our eyes - one minute thick fog, the next clear skies.
After eating we head off straight to Maeshowe to start preparing for our recording the following day. We have to walk through a low tunnel to reach the main chamber and itís really amazing, for something thatís 5000 years old itís in surprisingly good condition. Luckily there is also a power supply to help you see it.
Sunday 1st October
We start at sunrise so we can make the most of the morning. The site has to be handed back to Historic Scotland at lunchtime. We all lug heavy speakers, amp and sound kit across the field and into Maeshowe.
We set up our pink noise generator, a twelve-sided speaker and amp. Pink noise sounds like a medium sized waterfall and is used as an analogue for the kind of sounds that might have been created in Neolithic times.
As we walk around the room we notice areas where the noise is very loud and others where it seems to disappear. Standing waves! It is possible to reproduce this effect in most enclosed spaces - but imagine being deep within a burial chamber and drumming, humming or chanting among the bodies and possibly spirits of your ancestors - the sensation must have seemed very powerful.
There was another effect too, which Aaron says he has observed before - something called "helmholtz resonance". This sounds like the noise you get blowing across the top of a bottle and is a balance between air pressure and sound pressure. Volunteers have apparently reacted strangely to this noise in other experiments - some had out of body experiences, while others just felt ill.
We try this experiment using the constant beat of a drum in the passage way to the chamber and Aubrey feels a strange tingling. It has no effect on me at all. Maybe Iím distracted by the process of trying to record everything we do?
We spend the rest of the day visiting the standing stones near Maeshowe and trying to track down the elusive seals. We fail.
Thursday 5th October
Next stop Stonehenge. After the problems of getting to Orkney, Stonehenge seems like a breeze. We arrived a couple of hours before sunset because once again we have to work while the site is closed to the public. We have time for a quick walk around, take a few photos and eat a rock cake - all food at the Stonehenge cafe is themed around stones! Now we are ready to go.
We are privileged to be amongst the stones and imagine what people might have used them for. We practise drumming and the same experiments that we conducted in Orkney. Bizarrely they have a similar effect. As we walk around there are dead spots and loud spots. For what seems like an open space I suddenly realise how in fact parts are quite enclosed.
The experiments we do outside the outer ring also show how sound is kept in the circle. If there had been a ritual of some kind going on inside 4000 years ago, an observer would have been totally excluded - both physically and aurally!
The English Heritage staff say that when they have TV crews visiting, there has to be extra security laid on to stop inquisitive people coming over to investigate what the bright lights and activity are all about. Since there are just the four of us with a couple of camping lights and a torch it isn't deemed necessary, but I wonder what passers by make of the giant shadows we cast?
Arrive home at 1.30am utterly exhausted - now all I have to do is edit down six hours of recorded material and try and make a 28 minute programme about it. The task has just begun!"
Back to Jo.