This animated essay from the American Experience Web site explains the difference between alternating and direct electric current and offers in-depth explanations about the role played by a battery, light bulb, wire, and generator. Grades 6-12.

This segment from Swift: Eyes through Time traces the history military officers and engineers discovering a strange phenomenon in the sky that astronomers now know are gamma-ray bursts.

In this video segment, the ZOOM cast demonstrates how to use cabbage juice to find out if a solution is an acid or a base.

In this video segment adapted from ZOOM, two cast members demonstrate what happens when vinegar is added to baking soda inside a container. The resulting chemical reaction produces enough carbon dioxide to launch their paper rocket skyward.
Recommended for: Grades K-5

A car propelled by the reaction between lemon juice and baking soda has more in common with rockets and jet aircraft than one might think. In this video segment adapted from ZOOM, two cast members demonstrate the power of rocket-propelled vehicles and how to exploit the force produced by the carbon dioxide gas. Grades 3-8.

It would seem that bottles of lemon juice and rockets have only their basic shape in common. However, as two cast members from ZOOM demonstrate in this adapted video segment, when baking soda is added to the mix, a plastic bottle can act very much like a real rocket. Grades 3-8.

In this video segment adapted from ZOOM, cast members make their own hovercraft and demonstrate how the air leaking out of a balloon can make a plastic plate hover above a table.

This video segment adapted from Building Big illustrates the strength of the arch in bridge design and construction.

This media-rich series of interviews from the NOVA Web site explores the unique challenges faced by astronauts doing construction work in outer space.

In this interactive activity from ChemThink, take a closer look at atomic structure, properties, and behaviors.

This video segment adapted from A Science Odyssey takes a look at the scale of the atom and the tremendous amount of space between the electrons and the nucleus. If all this empty space exists in matter, how can any substance be solid?

In this video from DragonflyTV, Jai and Jonathan track, graph, and analyze the motion of basketball shots as they investigate what factors influence the accuracy of their game.

In this video adapted from NASA, two members of a NASA research team working to produce carbon nanotubes share some background behind this new technology, show examples of how it will be useful, and explain the various tests being performed to ensure readiness for spaceflight.

This video segment, adapted from NOVA scienceNOW, presents basic concepts of physics behind booming sand dunes. See how surface tension affects potential and kinetic energy and how it all works together to create sound.

In this demonstration of chemical change, the presenter blows breath into a methylene blue solution releasing carbon dioxide which acidifies the water and changes it from a bright blue color to green.

In this interactive activity from the Building Big Web site, use your knowledge of bridge design to match the right bridge to the right location in a fictitious city.

Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!

In this video segment adapted from ZOOM, the cast shows how the 34 steps in their Rube Goldberg invention use everything from gravity to carbon dioxide gas in order to accomplish one simple task: pouring a glass of milk.

In this video segment from ZOOM, Jillian explains how her simple machine uses marbles, levers, flowing sand, and a spinning wheel to water a plant.

How do you build a tunnel 32 miles long -- under water? This video segment adapted from Building Big, follows the construction of the Channel Tunnel (nicknamed "Chunnel"), the engineering wonder that connects England to France.