# Daisies in STEM - Archimedes Screw

Today we learned how scientists think and solve problems. One of the world's greatest scientists and mathematicians was Archimedes. He laid the foundation for important mathematical and physics concepts, and made many incredible inventions. Archimedes is famous for solving difficult problems, in particular the problem of the King's Golden Crown:

King Hiero II requested to have a crown made of a lump of pure gold. When the king received the crown, he suspected that some of the gold was replaced with cheaper silver. However, the crown weighed the same as the lump of pure gold, so he couldn't prove that gold had been stolen.

The king turned to Archimedes for help in solving the problem. It was a difficult problem, and Archimedes thought about the problem for a while. He though about the problem during breakfast, and when he walked in the street, and even when he was getting ready to take a bath. Archimedes was so distracted thinking about the problem, that he let his bath fill with water all the way to the top. When he sat in the bath some of the water splashed out. Archimedes noticed that the amount of overflowing water was proportional to his size. He jumped out of his bath shouting Eureka! Eureka! I've found it!

Archimedes realized that objects disperse water in an amount that is proportional to their size. He immersed the crown in water and found that the crown dispersed less water than the lump of gold, but more water than a lump of silver. Therefore, he concluded that the crown was made from gold mixed with silver.

We tested Archimedes theory by submerging different objects (shells, rocks, beads) in a cup with water and marking how much water was dispersed.

Archimedes invented many interesting things, one of them was the Archimedes screw. It is a very simple pump that can easily be made from a pool noodle and tubing. The girls worked in pairs to wrap tubing around a pool noodle to create the Archimedes screw. They tied a pipe cleaner to each end of the screw to secure the tubing in place.

This simple Archimedes screw works remarkably well. Water goes up the tube when the screw is turned, and drips from the top of the screw.

Fun!

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