an autodidact meets a dilettante…

‘Rise above yourself and grasp the world’ Archimedes – attribution

fountains: how good are the acoustics of the amphitheatre at Epidaurus?

leave a comment »

070405_greeks_acoustics_02

The small ancient Greek city of Epidaurus, about 50 ks due south-west of Athens, was a place of pilgrimage and hope to the sick, the halt and the lame for centuries, throughout the Hellenistic period, and well into the early Christian era. It was the haunt and reputed birthplace of the healer god Asclepius, as popular as modern-day Lourdes and no doubt just as efficacious. But it’s not the healing powers of Epidaurus that I want to focus on, it’s its amphitheatre, situated a few ks out of town, and renowned for its miraculous acoustic qualities.

The theatre of Epidaurus was designed by the sculptor and architect Polykleitos the Younger and built in the 4th century BCE. It was added to in the Roman era but fell into disuse after the fall of the empire. In 1881 it was rediscovered and renovated, bringing to light for modern audiences its extraordinary acoustic properties. The term ‘amphitheatre’ means a theatre in the round, and the one at Epidaurus was one of the largest of the Hellenistic era, though the great Roman amphitheatres were larger and more visually spectacular.

When I was a kid one of the first things I ‘learned’ about the ancient Greeks was that they were great speculators and hypothesisers but not much chop at proofs and other such practicalities. I’ve been unlearning that fact ever since, and the Epidaurus amphitheatre is another step along the way. It seats around 15,000 people, and was deliberately set in the open air against a beautiful backdrop of shrubbery. But no matter where you stand or sit amongst the tiers, you’ll be able to hear a coin drop or a match being struck centre stage. Tour guides are on hand these days to prove it to you.

A 2007 study of the amphitheatre  by Nico Declercq and Cindy Dekeyser of the Georgia Institute of Technology proved that the superb acoustics were no accident.  The seating, built from limestone, filters out sound waves of low frequency, thus damping background noise from the crowd. In addition, high-frequency waves are reflected from the rows of seats, which enhances the effect. The seats had a corrugated design which acted as an acoustic trap, damping the low frequencies, but the actors’ lines could still be heard because of a phenomenon known as virtual pitch, a complex process in hearing and harmonics which enables the brain to reconstruct missing frequencies, which we do all the time on our mobile phones and other electronic gadgetry.

All of this raises the question – did Polykleitos the Younger know exactly what he was doing?  I think the only proper answer is that we’ll never know for sure. If he left any written explanations as to why the seating should be built of limestone, with corrugations in the surfaces, those explanations have been lost, along with the majority of classical and Hellenistic Greek writings. Perhaps more importantly for these speculations, Greek and Roman amphitheatres built afterwards didn’t copy the Epidaurus design features.

This doesn’t necessarily mean Polykleitos didn’t know what he was doing – though he probably didn’t know exactly what he was doing. He would likely have been experimenting with materials and designs, trying to find the right acoustic effect for an amphitheatre, You might say he was fumbling about in the dark (or the acoustic equivalent) with a specific goal in mind. It wasn’t so much a matter of chance as chance favouring the prepared mind. And it’s the preparedness of mind of so many Greek intellectuals of this era that is so impressive.

Today we take for granted a scientific approach in which we work on the findings of others in order to reproduce them or disprove them or augment them, and so build up, tiny piece by piece, a more accurate and reliable picture of how our world works. To return to the ancient Greek world is to find the first glimmerings of such an approach, along with numerous attempts to ‘reinvent the wheel’, to start from scratch, because the kind of fleshed out, multi-tested, cumulative knowledge of the world that is today’s scientific picture didn’t exist then, and the difference is such that we can barely imagine ourselves in that world. It’s only by trying to think ourselves into that context that we can appreciate the achievements of such contributors to a world we now take for granted as Polycleitos and so many others – Pythagoras, Aristotle, Theophrastus, Hippocrates, Archimedes, Eratosthenes and Heron to name but a few.

I’ll end with a reminder of the importance of scientific research and the struggle to understand our world, from Erasistratus – a physician and early researcher on the heart, the nervous system and the digestive processes – writing some 2,300 years ago:

Those who are totally unfamiliar with research, once they begin to exercise their minds, become dumbfounded and immediately abandon the pursuit out of mental exhaustion, collapsing like runners who enter a race without prior conditioning. But the person who is experienced at research keeps trying every possible approach and every possible angle and, rather than giving up after a single day’s labor, persists for the remainder of his life. Focusing on one idea after another that bears upon what he seeks, he presses on until he reaches his goal.

Written by stewart henderson

November 17, 2013 at 10:06 am

Leave a Reply

%d bloggers like this: