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.
Bill Nye explains plate tectonics and the origination of its theory. The areas in which the tectonics spread apart is where volcanoes form. Conversely, the areas in which the tectonics come together is where mountains form.
Bill Nye is obssessed with erosion and explains that rocks change over time. He explains what causes weathering (although he calls it erosion): water, ice, wind, sand, and chemicals. He illustrates the process of erosion in his lab.