Edward Current produced a humorous take on the age-old question of God which also illustrates an important logical fallacy: proving a negative.
Although to be fair, there is stll a fine line between impossibility and improbability. A wiki entry puts it very well:
Though a lack of positive evidence can never disprove a hypothesis, a statistically large number of negative instances may make it highly improbable. For example, the lack of success in finding life on Mars, and the lack of a recognizable chemical signature of life, suggests that there is no life on Mars. However, it remains possible that we have not looked in the right place, or not recognized the evidence.