Waves

Through researching into the word collide, I ventured into looking at waves colliding with cliff faces and coast lines and came across this rather interedsting research into the earth's 'hum'...

"You can’t hear it, but the Earth is constantly humming. And some parts of the world sing louder than others.

When two waves of opposite direction but similar frequency collide, they create a special kind of pressure wave that carries energy to the ocean bottom. As these waves pound against the sea floor, they generate a constant vibration with a frequency of about 10 millihertz, much too low for humans to hear but easily detectable with seismometers. By comparing the intensity of the hum with the height of waves around the world, scientists can track where the buzz is coming from."
Source -  wired.com

This could be an interesting angle to approach the Silent Movie brief, although I couldnt communicate the 'humming' sound due to brief constraints. Something for the pin board...