Teacher resources and professional development across the curriculum

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Workshop 7

4. Entropy

heat differential

Entropy can be thought of as a measurement of the disorder of a system. All systems have a tendency to move from ordered states to less ordered states. Chuck provided an example with the box of marbles and, as anyone knows, a room in a home will become disordered over time and work has to be done to reorganize it and put things back in their places. But entropy has a deeper meaning with respect to energy. Whenever energy freely transforms from one form to another, it moves from easily accessible forms to less usable forms like heat.

If you think back to the example that you saw in an earlier show about the boxes that the mother was looking for in her child's room, we realize that the number of boxes was always the same. When all the boxes were in the chest, boxes—energy—were very organized; however, with each example it became more difficult for the mother to find and account for the boxes. The boxes and the room were more disordered with each situation. She could, of course, find all the boxes and bring them back to where they started in the chest by doing some work.

So, while we can decrease the entropy of a specific location or a specific object, somewhere else in the universe the entropy will increase.

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