Lucy travels through time to view the Earth at various periods in the past. As she travels, the setting behind her gradually changes in a timelapse. She visits the dinosaurs and eventually meets Lucy the Australopithecus.

This clip illustrates many of the important events in the story of life on Earth. It also explains the Geologic Time Scale, which is the system used to determine the Earth's age.

Bill Nye explains why it gets colder as one travels up through the atmosphere. He uses miniature replicas of a city and a mountain to support his explanation. Bill also briefly touches upon the lapse rate.

Lois removes the krytonite to save Superman. Superman is weak but flies above the clouds to take in energy from the Sun and recharge.

Phil walks us through the different layers of the atmosphere. He explains what we can expect to find at each layer and the concentration of air molecules at each level.