The set of circumstances which enables life to exist is compared to a mulyi-layered window wherein each pane is a life-limiting factor. If even one pane shifts too far in any direction, life would cease to exist. Drawing on his knowledge of physics and an extensive review of scientific literature and physical evidence, the author hypothesizes multiple asteroid impact as the catastrophic event which closed the "Window of Life," ushered in the great Ice Age and produced many of the physical characteristics and phenomena of our Earth and near universe which are otherwise not properly explained. The unthinkable chaos discussed herein has been described by Immanuel Velikovsky in his 1950's book entitled 'Earth in Upheaval'. Velikovsky understood that the major planets - possibly Mars and Venus- as well as certain comets were responsible for the disruption on Earth. This present work puts the blame on a swarm of minor planets (asteroids) instead. This position is easier to defend because there is no doubt that the Earth has been pummelled by numerous asteroids, several of which would have caused unthinkable chaos, a world-wide flood and a mass extinction. more info at http: //benatripp.wix.com/window-of-life