Transcript: The big bang model provides a good description of the current universe which is large and cold and mostly empty. It implies that the early phase was hot and dense. The big bang model is supported by the observation of galaxy recession, by the light element abundance which is consistent with cosmic nucleosynthesis in the early hot big bang, and by the presence of cosmic microwave background radiation, smooth and isotropic suffusing space as leftover radiation from the big bang itself. This is a great success of the scientific method, but how far can we push the big bang model? Spurred by its success, theorists have been driven to speculate about the earliest moments of the universe’s existence. Some of this is pure speculation, but other ideas are based on well understood laboratory physics as physicists and astronomers combine to talk about the first fractions of a second of creation after the big bang.