Repeatedly, supernatural explanations for physical events (such as comets, eclipses, earthquakes, lightning, plagues, design in nature, Cambrian fossil explosion) later turned out to be scientifically explainable. Even questions surrounding the origin of our universe, its apparent fine-tuning and the origin of life are yielding to scientific investigation. As scientific knowledge continued to advance over the past 400 years, supernatural explanations for events continued to retreat and retreat. Many scientists faced with such a consistent trend have extrapolated to the conclusion that all of our earthly gods are non-existent and our holy books merely human creations.