By now you should have a handle on the material properties of the interior of the Earth. In this lesson you made some simple optical measurements and extended them to figure out some properties of the Earth's mantle. You know why seismic waves take the paths they take and about how long it takes them to do it. You also found out the current state-of-the-art thinking about how hot the center of the Earth is and what it is made of. Oh, and hopefully, you got to eat some Pez candy, too.
Reminder - Complete all of the lesson tasks!
You have finished Lesson 4. Double-check the list of requirements on the Lesson 4 Overview page to make sure you have completed all of the activities listed there before beginning the next lesson.