Caving was such an awesome experience. Cesar was our tour guide. He told us a story about a man who stayed in the cave for 61days without any knowledge of time, trying to beat a record. Psychologists did experiments on his progress. He was so desperate for knowledge of time that he measured a cup filling with water using the length of a song in his CD player. Once his CD player died, he observed the bats that came and left the cave. The researchers trapped the bats to keep him from having any sense of time. Caves are intriguing to us, because they are dark. Humans depend so much on sight as our primary way of perceiving the world.