Why there is no evidence of alien life? TED talk

Stand by for an animated exploration of the famous Fermi Paradox. Given the vast number of planets in the universe, many much older than Earth, why haven't we yet seen obvious signs of alien life? The potential answers to this question are numerous and intriguing, alarming and hopeful. (Part of the series "Questions no one knows the answers to") "Why Can't We See Evidence of Alien Life?" was animated by Andrew Park (http://www.cognitivemedia.co.uk)