This document discusses the earth's magnetic field and how it was studied and understood over time. It asks questions about William Gilbert's hypotheses about compasses and the earth's core in the 1500s. The earth functions similarly to a bar magnet, with Gilbert originally thinking the core was made of sulfur but it is actually made of iron and nickel which helps create the magnetic field. The magnetic and geographic poles are not in the same locations. Magnetic declination changes over time and was important for navigators to understand. The earth leaves a record of its magnetic field changes over time in rocks. The magnetosphere is shaped by solar winds and protects the inner Van Allen radiation belts. Solar wind particles enter the atmosphere at the magnetic poles.

1. 1.3-Magnet Earth-Pages 22-27N Journal Page 13
CSRQ Reading Guide-follow the correct form for writing these answers in your journal
1. Who studied compasses in the 1500’s? What was his hypothesis? Was his hypothesis
correct? How do you know?
2. How is the earth similar to a bar magnet?
3. What did Gilbert assume made up the core of the earth? Was this true? What is in the core
of the earth? How does this help the earth create a magnetic field?
4. Are the earth’s magnetic poles the same as the geographic poles? Give a precise example.
5. What is magnetic declination and why is important that navigators understand this term? Is
magnetic declination fixed or does it change?
6. How does earth form magnets out of ferromagnetic material?
7. Explain how earth leaves a record of the magnetic field. What does this record tell us about
the magnetic field of the earth?
8. What is the magnetosphere and how is this area shaped by solar winds? What are the Van
Allen Belts?
9. What happens when particles from solar winds penetrate earth’s magnetic field at the
poles?
1.3-Magnet Earth-Pages 22-27N Journal Page 13
CSRQ Reading Guide-follow the correct form for writing these answers in your journal
1. Who studied compasses in the 1500’s? What was his hypothesis? Was his hypothesis
correct? How do you know?
2. How is the earth similar to a bar magnet?
3. What did Gilbert assume made up the core of the earth? Was this true? What is in the core
of the earth? How does this help the earth create a magnetic field?
4. Are the earth’s magnetic poles the same as the geographic poles? Give a precise example.
5. What is magnetic declination and why is important that navigators understand this term? Is
magnetic declination fixed or does it change?

2. 6. How does earth form magnets out of ferromagnetic material?
7. Explain how earth leaves a record of the magnetic field. What does this record tell us about
the magnetic field of the earth?
8. What is the magnetosphere and how is this area shaped by solar winds? What are the Van
Allen Belts?
9. What happens when particles from solar winds penetrate earth’s magnetic field at the
poles?