You may have heard the philosophical question:
"If a tree falls in the forest and nobody hears it, does it create a sound?"
Yes, of course, the tree make sound when it tumbled to the ground. But how do you know that something makes a noise if you did not hear it? Can you be sure?

Want to trade/swap an ATC? Read here to see how: http://ewian.blogspot.no/2012/12/atc-artist-trading-cards.html

Medium used: watercolour and gloss medium