In this video segment from NOVA scienceNOW, meet researchers who are studying obesity and trying to understand the role that hormones and genetics can play in regulating appetite.

In this video adapted from the Encyclopedia of Physics Demonstrations, learn how plotting the changes in an object's position on a graph can provide information about the object's motion.

In this video from Science City, meet Romiya Glover, a chemist who develops products for HIV/AIDS testing. She describes the multidisciplinary nature of her job, how she decided to go into science, and how her work benefits others.

Learn about rotational forces by watching astronaut Jeffrey Williams spin objects onboard the International Space Station in this interactive activity adapted from NASA.

Astronomer Carl Sagan discusses the possibility of time travel in this audio-enhanced interview from the NOVAWeb site.

In this video segment adapted from Northwest Indian College, Lummi Elders explain how a decline in the availability of salmon reflects a threatened environment that must in some way be protected.

This animation adapted from NASA shows the orbital paths of spacecraft in NASA's Earth Observing Fleet that are a source of wide-scale, primary research about Earth.

This video from Thinkport introduces the seahorse, an unusual, endangered fish that has puzzled scientists who are attempting to save it.

In this video segment adapted from the College of Menominee Nation, tribal members share examples of how seasons are changing, and how these changes are affecting local plants.

This video segment adapted from Northwest Indian College reveals how Native American life and knowledge is connected to natural cycles.

This interactive feature from the NOVA "Shark Attack!" Web site details the six senses sharks use to find and capture their prey.

In this video from Science City, Shaundra Bryant Daily, an electrical engineer, describes a software program she developed to help girls reflect on their emotions, and how her two passionsí_í_íŹscience and danceí_í_íŹare connected.

In this video excerpt from NOVA, learn about the advantages, disadvantages, and ethical implications of screening for genes associated with diseases, including those linked to breast and ovarian cancers.

In this adapted ZOOM video segment, cast members calculate how much water they each use during a typical shower. They compare their results to their original predictions.

Background image of normal disc-shaped red blood cells from the University of Utah. Inset shows sickled red blood cells, curved and rigid, from the Virginia Medical College.

Amy Smith is an engineer who designs simple and inexpensive solutions to real-world problems. This video produced for Teachers' Domain features her innovative design for testing the safety of drinking water in the developing world.

In this video segment adapted from NOVA scienceNOW, learn about engineering innovations that could help detect a bridge's structural weaknesses before they become dangerous.

In this lesson designed to enhance literacy skills, students learn how animals' physical characteristics, such as jaw structure, are directly related to the function they perform when the animal interacts with its environment.

This video segment adapted from NOVA/FRONTLINE looks at American energy consumption and the resulting production of greenhouse gases.

In this video from DragonflyTV, follow the investigation of Isaac and Anjali as they record, measure, and analyze data about how the Sun's position in the sky affects a solar-powered car's speed.