The story is told of a biologist who was walking through Times Square in New York City, with a friend at high noon, when suddenly the biologist exclaimed, “oh, listen to that cricket.” The friend stared at him in total disbelief. “how can you hear a cricket, above all this racket and noise?” he asked. Without a word, the biologist reached into his pocket, seized a big handful of change, and dossed the coins up into the air. As they bounced on the pavement below, everyone around them whirled around and pounced on the coins. “See,” said the biologist to his friend, “we hear what we are listening for.”
What Color is your Parachute?