Broadcast (2002) As we go through our lives driving cars, exploring the Internet, studying the world around us it is hard to imagine that we're related to Earth's other animals. It's even a stretch to see what connects us with the rest of the chordates, a group of about 50,000 species including the vertebrates like fish, amphibians, reptiles and birds, mammals and ourselves. But indeed, all chordates, from the worm-like amphioxus to Homo sapiens have three common features.
Horizon uncovers the secret world of our dreams. In a series of cutting-edge experiments and personal stories, we go in search of the science behind this most enduring mystery and ask: where do dreams come from? Do they have meaning? And ultimately, why do we dream?