The Mayans constructed their temples so that a handclap at the base of the temple produces an echo that sounds like the call of the sacred Quetzal bird, which they believed was a messenger of the gods. The technique is now known as a “Bragg diffraction grating.” – WTF Fun Facts
Source: Here’s How This Ancient Mayan Pyramid Makes Bird Calls (gizmodo.com)
Yet another ancient concept “rediscovered” and named after a white man…