circumference and pangaea

Exposition presentations have begun! This afternoon, Ben and Lola showed off their braininess to us.Ben's project started with the question, "Who was the first person to discover that the earth is round?" Throughout Expression, he has explored the shifting of tectonic plates and the make-up of the layers of the earth. He discovered that a Greek mathematician Eratosthenes had calculated the circumference of the earth using the shadows in the cities of Syene and Alexandria, and used this same idea to calculate the circumference on his own, with help from Mackenzie and Mackenzie's dad in San Diego. Initially, he explained, he got the calculation wrong because of an incorrect assumption about degrees, but he fixed the issue and ended up with the actual number.Lola brought us over to the dining room to talk to us about her work on Pangaea. She explained that at first she had no idea what continents even were and thought the project would be really hard, but she learned a lot about why it looks like the continents fit together - because they once did! She did a lot of research and learned about tectonic plates and the ways they move. She told us that one of the reasons scientists know that Pangaea existed was because fossils are similar on the edges of certain continents and that animals - like ostriches and emus - have developed similarly. Then she showed us her awesome music video. Check it out here!Also, many thanks to Bryan and Gladys, from the Cayman Islands, for feeding us hot lunch today! Our stomachs greatly appreciate it!