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 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.

In this video segment adapted from A Science Odyssey, learn about bubonic plague and how city officials in San Francisco tried to contain its spread in the early 1900s..

In this interactive activity from Shedd Aquarium, build a fish and then release it into the reef to search for food and evade predators. Try different combinations and observe how each kind of fish has unique adaptations that help it survive in its habitat.

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.

In this video segment from PEEP and the Big Wide World, children make a dam with dirt, sticks, and stones to try to stop the flow of water.

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.

In this Cyberchase video segment, the CyberSquad must estimate the measurements of Spout the Whale in order to find a cage that will fit him.Ű_í_

In this video segment from Cyberchase, Inez and Lucky figure out how to keep track of the number of clones as they continue to multiply.

In this video segment from Cyberchase, the CyberSquad measures Judge Trudy's land claim by using tarps, fence posts and a grid made with rope.

In this video segment adapted from NOVA, find out how cars made of a material stronger than steel and half the weight can help combat climate change.

In this video segment from NatureScene, explore Cartwheel Bay, a wetland in South Carolina, and learn about the variety of carnivorous plants native to this unique landform.

In this video adapted from Texas Parks and Wildlife Department, learn about carnivorous plants that act as both producers and consumers in an ecosystem. See sundews and blatterworts capture and digest insects.

In this video segment from Cyberchase, the CyberSquad and Digit construct a physical profile of the person who kidnapped Choocroca, a giant cybercrocodile.

This interactive resource adapted from the National Park Service presents the key concepts of cave and karst systems, including how and where they form, different types, and various cave environments.

This interactive feature describes some of the most important structures and functions of the cell membrane.

In this interactive activity from NOVA, discover how centripetal force can affect you when riding in a car or flying at high speeds in a fighter jet.

This video segment explains centripetal force and illustrates how roller coasters rely on it to give you a thrilling ride.

In this video adapted from the Arctic Athabaskan Council, learn how warmer temperatures in the Arctic are transforming the landscape, triggering a host of effects such as permafrost thawing and insect infestations.