Sound at Stonehenge
I’m currently working with a group of bloggers on a site to be launched somewhere in the next few months. I’m not sure where yet. One of the features of the site is an informal rule that we won’t comment on news till at least seven days have passed from making the headlines. There’s a couple of reasons for this.
We’re all busy. Chasing the news is work and takes time. If we get stopped before we can finish it could be a while before we pick up the story again. In the meantime hot news has become old cold news and the key points have already been said a dozen times by everyone else. The post gets spiked and the time is wasted. Intentionally planning for a longer cycle changes how you approach a story and gives you not just the story to analyse but also the reaction too. In the case of the Stonehenge acoustics story the reaction is more interesting than the base story itself.
As a reminder Stephen Waller presented a talk at a meeting of American Association for the Advancement of Science in Vancouver. In it he proposed that the design of Stonehenge was related to auditory interference patterns between the sound of two flutes being played. Andy Burnham points out the obvious problem in his comment.
“Waller rigged two flutes to an air pump so they played the same note continuously” OK, fine, so how on earth is this relevant to the practicalities of an ancient society? In order to get strong, static cancellations in the sound you would need equal and unvarying sound pressure levels from each instrument, and for the sources to be from the same two points in space. How precisely would two flute players do this in practice without an air pump? ie having to take breaths and carry on this trick for any length of time. This is utter nonsense.
Andy Burnham is pretty much gold in this thread. In reaction to the idea this sound could be achieved by circular breathing, he also adds:
I don’t thin circular breathing is the answer — it’s pretty difficult on low resistance wind instruments such as the flute. Didgeridoos and suchlike won’t exhibit this effect — you need a high frequency pure tone — as close to a sine wave as possible — ie a flute. Bagpipes wouldn’t work either, unless someone invented some sort of ‘flute bagpipes’. A reedy bagpipe sound is rich in harmonics. The harmonic frequencies from the two instruments won’t create standing wave cancellations in the same places in space as the fundamental tones, so you won’t get same strong cancellation effect. And as I said you also need two fixed amplitudes and closely fixed point sources for the effect to work.
Sound is a difficult subject for archaeologists. Flutes or pipes seem likely, as to drums, but the closest prehistoric musical instruments, that I know archaeologists have found, are lurs from Denmark. These date to around the 8th century BC and survived because they were bronze, not organic material like wood or bone. You can see them in the logo for Lurpak butter. It’s been a while since I’ve read about this, so I’d be surprised if there weren’t now something older known. There are a couple of candidates for bone flutes that are older, this is the most promising artefact, but I don’t know how widely accepted they are yet.
Even though there’s scant evidence for music in the Neolithic and Bronze Age British Isles, it’s an odd leap to say it didn’t exist. Music in some form seems to be a constant in human society, so this is where a minimalist approach breaks down. But it’s not just musical instruments that are missing. I suspect a lot of Stonehenge is missing too.
Bits of it have broken off and it’s easy to spot where stones were missing but refilling these gaps, as many reconstructions do, doesn’t go far enough for me. The stones are the skeleton of Stonehenge. We don’t know if they were the whole body. We do know that the skeleton was a lot of work. The hard sarsen stones are crafted like wood, with tenon and mortice joints. Archaeologists currently believe that the bluestones were transported from far Wales. In light of this what else would have been at a living Stonehenge?
If you visit places of worship in modern times, there’s a bit more than stone. There’s wooden seats, often decorated rather than plain. The walls are painted, windows often decorated. It’s not unusual to find holy books n plush velvet cushions and textiles dyed in striking colours drawing the eye here and there. We also know textiles were used in Neolithic and Bronze Age times. So after the thousands of man-hours shaping the stones, how likely is it that Gareth turned to Shane and said: “That’s that done. No point in wasting time decorating it with tartans or drapes. That’ll just be tedious and gaudy.”?
Once you add textiles into Stonehenge the acoustic and visual properties change. There are many arguments that “If you look out of this gap you can see this star,” but you can’t if Blodwyn’s nifty ethnic rug is in the way. As scientists archaeologists need a minimalist model of Stonehenge as a foundation to build on, but this minimalist model is an unfinished work. It’s a tool to build an idea of what Stonehenge looked like on. If you’re going to say that it’s the finished model and we don’t need textiles, then all reconstructions should show anyone there naked because there’s no evidence for the clothes people wore there either.
As Andy Burnham pointed out, Steven Waller’s approach misses the practical use of Stonehenge by ancient peoples, and in this case adding people into the past makes Waller’s proposal either unworkable or an astonishing Jenga tower of special pleading. It’s safe to say I’m unconvinced, but I’ve not been too impressed with some of the reactions to the story either. “Crank’ seemed a common opinion, If Steven Waller were a crank then by presenting his work at a scientific conference he’s still closer to professional practice than archaeologists who issue a press release now before a talk in a few months time.
In fact a browse of his website shows he’s not likely to be a crank, just terribly unaware of the differences in approach between US and UK prehistory.
The bulk of his work is on rock art at American petroglyph sites. The acoustics of rock art in the US is a new field, but producing some interesting results. Some archaeologists are finding archaeoacoustics much more intriguing than, to pick a random example, archaeoastronomy. But American prehistory is different to British prehistory. They have a richer rock art record, especially in the southwest. They also have ethnographic records and research that can help connect meaning to symbols. It’s not perfect, and I’d like to debunk one interpretation of a site this summer, but it’s very very different to the limited things we can say about rock art here. It means that Waller’s American work can rely on cultural information that we simply don’t have here. What is accepted by US archaeologists about US sites is extremely speculative when applied to UK sites.
Very few people have commented on work around archaeoacoustics in general in relation to this story. A few commenters have mentioned Deveraux’s work, but mainly the thrust has been this story must be debunked. I don’t think for a moment archaeologists have consciously decided the outsider must be expelled, but I wonder if an eagerness to portray this as nonsense indicates something more. Subconsciously does rejecting Waller as nonsense and the opposite of what you do mentally reaffirm that your own theories must therefore by default be sound reasoning?
For something more positive about how sound can be explored in archaeology, Alan Boyle has written an interesting piece on MSNBC’s Cosmic Log.