The intricacies of Earth's magnetic field are an ongoing area of research. We understand many things about the field, such as how the clues it leaves behind in the rock record can be used to test the hypotheses of seafloor spreading and tectonic motion. There are also parts of it we don't understand, such as exactly how it has sustained itself for 3500 million years and what really causes a reversal to happen. Finding out how living things on the planet use the magnetic field is also a fairly new discovery. Do you think humans use the field unconsciously? Is this why some people are good at finding their way around and others get lost all the time? Perhaps, if you are one of those people who refuses to ask for directions, you can give the excuse that you are getting in touch with your ability to perceive the magnetic field.
Reminder - Complete all of the lesson tasks!
You have finished Lesson 3. Double-check the list of requirements on the Lesson 3 Overview page to make sure you have completed all of the activities listed there before beginning the next lesson.