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offers two online science units for middle-school students. Antarctic Exploration tells the story of Sir Ernest Shackleton's 1914 expedition to Antarctica and how, when his ship became icebound and was crushed to pieces, he and his crew survived before being rescued two years after their journey began. Ocean Currents Exploration tells how Ben Franklin charted the Gulf Stream, a current in the Atlantic Ocean, to help speed mail delivery from Europe to the U.S. (TERC, National Science Foundation)
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In the third century B.C., the Greek astronomer and mathematician Eratosthenes estimated the Earth's size by comparing the shadows cast at two locations at noon. He used his knowledge of triangles, circles, and angles to calculate the Earth's circumference to within one percent of the actual measurement. |
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Endurance in the ice |
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