1900 Air Pollution

Examine this graph from FRONTLINE/NOVA: "What's Up with the Weather?" Web site to see dramatic increases in three greenhouse gases over the last two hundred years.

1964 Alaska Earthquake

This video adapted from the Valdez Museum & Historical Archive, explores what happened during the Great Alaska Earthquake of 1964 through original footage, first-person accounts, and animations illustrating plate tectonics.

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The 2008 Wall Street Bailout

This video segment adapted from FRONTLINE: "Money, Power and Wall Street" traces the unprecedented decisions made by the U.S. government to intervene in the financial crisis of 2008.

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20-Year Map of Global Rainfall

This visualization from NASA shows global rainfall patterns over a 22-year span. It incorporates data from a combination of remote-sensing and ground-based sources.

70% Female

This Wide Angle video features the women of Rwanda who have emerged as outspoken leaders and the great strides they have made toward rights and equality.

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Abel Meeropol, Billie Holiday and A Song Born in Protest

Learn about teacher and author, Abel Meeropol who penned the haunting song of protest, Strange Fruit, in this segment from Independent Lens.

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Above the Clouds: Telescopes on Mauna Kea

This video segment adapted from First Light explains why the highest peak in the Pacific, Mauna Kea, is an ideal site for astronomical observations. Featured are new telescope technologies that allow astronomers to explore the universe in more depth.

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Abraham Lincoln's Words

In this video excerpted from the PBS series Looking for Lincoln, Professor Henry Louis Gates, Jr. cites several examples of Lincoln’s use of “seemingly simple but profoundly eloquent language to express and ennoble his cause.”

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Abraham Lincoln, Attorney at Law

This video segment, excerpted from the PBS series Looking for Lincoln, explores Lincoln’s years as a "prairie" lawyer.

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Abraham Lincoln: A Good Man? or A Good Man!

In this lesson, students use video from American Masters: Bill T. Jones: A Good Man along with primary sources to investigate the life of Lincoln and write a one page argument essay on whether Lincoln was "a good man."

Accidental Discoveries

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.

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AC / DC: What's the Difference?

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.

Achieving Peace

This video from Women, War & Peace features a sit-in and other nonviolent actions conducted by the women of Liberia in 2003 to get participants at the peace talks in Accra, Ghana to sign a peace agreement in order to bring about the end of civil war in Liberia.

Acid Lake

Add acidity to a healthy lake and see what happens to the plants and animals in this interactive activity adapted from EcoKids.

Acids and Bases: Cabbage Juice Indicator

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.

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Acids and Bases: Kitchen Chemistry

In this interactive activity from the ZOOM Web site, search for chemistry clues and experiment with acids and bases in a virtual kitchen.

Acids and Bases: Making a Film Canister Rocket

In this video segment, ZOOM cast members mix different amounts of baking soda and vinegar to see which combination produces the most carbon dioxide for launching a film-canister rocket.

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Acids and Bases: Testing Rockets

What happens when you mix baking soda and lemon juice? Watch the ZOOM cast launch a rocket using kitchen chemistry.

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The Advantage of Sex

Why did sex evolve? The likely answers, in this essay for the Evolution Web site by science journalist Matt Ridley, may surprise you.

Affirmative Action and the USA

In this video from Wide Angle, two American NAACP lawyers arrive to advise Brazilian civil rights organizations, leading to a discussion of differences between race relations in the U.S. and Brazil.

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After Slavery

In this video segment from Finding Your Roots, Kevin Bacon learns how his ancestor dedicated her life to educating freed slaves.

Aging Diamonds?

In this video from Nature, geological detectives use ancient diamonds to learn more about Earth's inner layers.

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Agony of Defeat

Students are asked to explain how forces and motion affect the skier in the film.

Alabama Christian Movement for Human Rights Scrapbook

These materials document the goals and activities of the Alabama Christian Movement for Human Rights; from the Birmingham Civil Rights Institute.

Alaska Native Pilots

In this video adapted from Storyknife Productions, Alaska Native pilots share how they use traditional knowledge to read the landscape and predict the weather.

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Alaska Native Teens Help Researchers

In this video adapted from KUAC-TV and the Geophysical Institute at the University of Alaska, Fairbanks, Alaska Native students contribute to research on how their environment is changing as a result of global warming.

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Alaska Tsunami

In this video adapted from Alaska Sea Grant, discover why multiple tsunamis resulted from the Great Alaska Earthquake of 1964.

All-Female Enterprise

This Wide Angle video looks at the advantages and disadvantages of running a small-scale, female-only business.

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All for One

In this video from Wide Angle, learn about the influence of the communist values of organization, discipline and collectivism on North Korean society.

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All in the Family

This video from the series Faces of America details the process of documenting family history and tracing lineage back through maternal and paternal lines.

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All in the Family

In this Evolution Web feature, test your skills at judging who's who on the tree of life while you learn about the tools and methods of cladistics.

All Planet Sizes

This illustration from the Lunar and Planetary Laboratory shows the approximate sizes of the planets relative to each other. Note that the planets are not shown at appropriate distances from the Sun.

All Things Lincoln

This video segment, excerpted from the PBS series Looking for Lincoln, explores the ongoing cultural fascination with physical artifacts of Abraham Lincoln’s life.

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Alternative Energy

Students are asked to explain what needs to be considered if alternative energy sources are to be used.

Alzheimer's Disease

This video segment from the Secret of Life School Video: "Genetic Medicine: Tinkering with Our Genes" explores the potential for gene therapy to cure diseases like Alzheimer's.

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Amazon Rainforest

This video segment from the Race to Save the Planet teaching module "Saving the Diversity of Life" describes the ecological value of tropical rainforests and explores some of the causes of their destruction.

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American Muslim Women

Learn about the perceptions and challenges of being a Muslim woman in the U.S., in this video segment from Religion & Ethics Newsweekly.

Amplitude

This interactive activity adapted from the University of Utah's ASPIRE Lab shows how a pendulum's amplitude changes as you set it swinging from different distances from its axis, and how the amplitude of a sound wave changes as you adjust the volume.

An Alaska Native Community Helps Seals

This video from First Alaskans Institute spotlights the Alaska Native community of St. Paul and its hands-on commitment to care for the land and animals on which it depends.

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Analyzing an Ecosystem

In this interactive activity adapted from the University of Alberta, identify the living and nonliving things in an ecosystem. Then look further at the living things to identify the producers, the consumers, and examples of mimicry.

Analyzing McCulloch v. Maryland

In this lesson, students watch a video segment from the PBS series The Supreme Court about the landmark case Maryland v. McCulloch while considering the powers of the national government and state governments.

Analyzing Primary Source Media

In this media-rich, self-paced lesson, students analyze primary source news footage to gain insights into public sentiment toward historical figures, issues, and events of the past 50 years.

Anatomy of a Rover

In this interactive activity from NOVA, learn about the sophisticated scientific instruments on two identical robotic rovers that have explored Mars — Spirit and Opportunity.

Anatomy of a Tsunami

Using visual models and other graphics, this interactive activity from NOVA Online reveals details of the December 26, 2004 tsunami that collided with coasts around the Indian Ocean.

Anatomy of a Volcano

In this interactive activity from NOVA Online, explore the main features of the Nyiragongo volcano, located in the Democratic Republic of Congo, and learn what risks it poses to the 500,000 people who live in its shadow.

Ancient Farmers of the Amazon

This video segment from Evolution: "Evolutionary Arms Race" tells the story of the leafcutter ant and the fungus it farms -- an example of mutually beneficial symbiosis.

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Anglerfish

This video segment from NOVA: "Animal Imposters" shows the lightning-fast strike of the anglerfish.

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Animal Babies

This interactive slide show illustrates the variety of animal babies that exist on earth -- some completely independent and others deeply reliant on parental care.

Animal Body Plans: Homeobox Genes

The homeobox genes that define the basic body plan of mice and fruit flies are illustrated in this graphic from The Human Evolution Coloring Book by Adrienne Zihlman. The accompanying article describes how these genes act as "molecular architects" in all animal species.

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Animal Classification Game

Learn about classes of animals and test your ability to identify animals as mammals, birds, reptiles and more in this interactive activity adapted from Sheppard Software.