Three Dimensions

Get in touch with geometry at Interactives: 3-D Shapes, www.learner.org/
interactives/geometry. Everything around you can be measured by its length, width and height. Put math into motion when you work through polyhedra, prisms and pyramids. Each section features fantastic examples that demonstrate the basic concepts in geometry. Learn new vocabulary and brush up your mathematical knowledge as you watch different shapes rotate and unfold before your eyes. Test Your Skills awaits when you are ready for a challenge.

GPS Free

Never Lost: Polynesian Navigation, www.
exploratorium.edu/never
lost/#/home, examines how Pacific islanders used natural resources to find their way as they explored the ocean and islands that surrounded them. Click on Canoe to figure out how these boats were built, and then make sure to check out provisions to get ideas on what to pack. Once you are ready to set sail, move on over to the Basics of Wayfinding to see what it takes to plan a route and stick to it when the going gets tough.

Road to Freedom

Learn the real meaning of sacrifice when you visit U.S Rationing During WWII, www.smithsonianeducation.
org/idealabs/wwii. Mouse around on the painting to highlight the different areas, such as Home Front Ammunition, Wartime Shortages and Everyone's Duty. Americans did without both luxuries and common items to help the war effort. Coffee, meat and gasoline were just a few of the things that had to be rationed. From historical posters to short movies, there is a lot of valuable material at your fingertips.

What are you going to do during
Thanksgiving break?

Speak Out Here!

Dear Amy: Does Mars or any other planet have life? — Kavya, Kumbakonam, India

Dear Kavya: The only planet that we know has life is Earth, but that won't stop scientists from searching for signs of life elsewhere. One of the things they look for is water, because it is a source of oxygen, which is essential to life on Earth. In addition, water can provide protection from UV rays. Scientists also look at the climate or clues of the past climate on a planet, because life is able to survive only in a small window of temperature. A planet can't be too hot or too cold.

Since the '70s, NASA has been searching Mars for signs of life. So far, there has been no evidence of life, but it's possible that life once existed there. Billions of years ago, the surface of Mars flowed with water and was much warmer. To learn more about the possibility of life on Mars, visit www.nasa.gov/audience/forstudents/postsecondary/features/mars_life_
feature_1015.html.

There are other stars and planets in the universe, so it's possible that life exists somewhere else. Visit Hunt for Alien Worlds, www.pbs.org/wgbh/
nova/worlds, and decide for yourself whether aliens might exist.

—Amy

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