- View more resources from this publisherPerimeter Institute for Theoretical Physics
Why Is It Dark at Night?
Alice wonders why it’s dark at night. If we are in an infinite Universe, why isn’t the sky full of starlight. Bob suggests that for some reason the light from the very distant stars hasn’t reached us yet. This leads on to the idea that the universe has a beginning and an age. This clip could provide a lead in to topics such as the speed of light, the expansion of the Universe and the Big Bang.
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