The Acoustics of Epidaurus
Drop a coin on the stage of this ancient Greek theatre, and people in the top row can hear it.
What was reported
The theatre at Epidaurus, built in the 4th century BC, seats around 14,000 people in a great semicircle of stone rows set into a hillside. It's famous for its acoustics: guides like to show that a coin dropped or a match struck on the stage can be heard in the highest seats.
It's still used for performances of ancient drama every summer.
Explanations offered
A 2007 study by researchers at Georgia Tech found that the rows of limestone seats act as an acoustic filter, damping low-pitched background noise such as the murmur of the crowd while letting the higher frequencies of actors' voices through; listeners' brains fill in the missing low tones. Later studies suggest the effect is a little less magical than the guides' demonstrations.
- When
- Built in the 4th century BC
- Where
- Epidaurus, Argolis, Greece
- Witnesses
- Audiences for more than 2,000 years
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.