Exploring and Thinking about Magnetic Fields
Introduction
Magnetism: You already know a lot about magnetism. This series of explorations—not experiments, because experiments are more formal and require careful measurements, and demand many more controls—will refresh your memory about magnets and help you appreciate a key element of the Sun. As you explore, be as careful as possible in organizing your explorations and recording the thoughts you have and the observations you make.

Be Safe: Iron filings can be dangerous to eyes and may get into cuts. Handle iron filings with great care. If you have a cut on your fingers or hand, bring latex gloves to school on the day of these explorations. Work carefully, be neat, clean up when you are finished. And return all of the materials to the teacher when you are done.

Equipment
• 2 bar magnets
• Compass
• 2 sheets of white paper
• Iron filings
• 2-2’ pieces of string
• 1 small ball bearing.
• Metric ruler
• Masking tape
• Lined paper to record your thoughts and observations.
• A pen or pencil

Time: Work fast and finish all of these explorations in one period!

Exploration
Process, Questions, and Observations
1. Equipment: Two Bar Magnets/ Sheet of Paper. Let’s start with an exploration you have probably done many times before. But it’s worth repeating to get your minds focused. Lay the magnets end to end on the sheet of paper. Do the magnets push each other away or attract each other? Turn one magnet around. What happens? Quickly describe what happens and explain why.
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.]
b. You might have jotted down something like this.
c. Magnets can attract and push each other away using the magnetic force that is a push or a pull. Their ends are different and they react differently depending upon which end of one magnet is near which end of other. Did you use words like North or South end of magnets, or positive or negative ends of magnets?

2. 2 Bar Magnets / Ball Bearing / Piece of Paper / metric ruler (flat table or desk)
A. Place ball bearing and 1 bar magnet on paper. Use ruler. How close can you move magnet to ball bearing before it moves. Mark distance at which ball starts to move on paper. What force attracts ball bearing? How does the ball bearing behave as it gets closer to the magnet? Are the other magnets in the class attracting their ball bearings from the same difference? Quickly write down your answer and observations.
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.
b. You might have jotted down something like this.
c. Magnets attract objects from a distance. The distance can be measured. If the distance is too great the magnet will not attract an object. The closer the magnet gets to an object the quicker the object moves to the magnet.
B. Lay two bar magnets on top of each other. Does this change the distance to the Ball bearing before it starts rolling? Why? Quickly describe what happens and guess why.
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.
b. You might have jotted down something like this.
c. Two magnets appear to create a greater force than one magnet. The force works at a greater distance. We can’t say the force is twice as great because we’d have to do an accurate experiment to prove this. We’d need more experimental controls. Did you explore how the ball bearing moved when placed on the side of the bar magnet at various distances.

3. Compass and paper / bar magnet and string / paper and two bar magnets, string taped to north end of one and south end of other, and iron filings. A series of explorations all linked together.
A. Tape paper to level desk or table. Place compass on paper. Mark directions of compass points on paper. On paper label the line the compass points, the “North / South line.” Put N at north end and S at south end of line. The compass points north and south. Why? Quickly write down your guess.
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.
b. You might have jotted down something like this.
c. The compass appears to react to a force in the air. This must be the Earth’s magnetic force. The compass lines up with a magnetic line. Is the compass a magnet? Did you see if it attracted the ball bearing? That’s okay, you have to work fast.
B. Take compass off of paper. Tie string to center of one bar magnet, suspend above North / South line you drew on paper. What happens to magnet? Why? Quickly write down your observations.
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.
b. You might have jotted down something like this.
c. Bar magnets line up in the same direction as compass needle. North end of magnet points north. South end points south. Magnet lines up with Earth’s magnetic field.
C. Lay magnet on paper in a direction vertical to (across!) North / South line on paper. Bring the compass over, and close to the bar magnet. Which way does compass point? Why. Quickly write down your guess. (Hint which magnetic field is stronger? Earth’s or Magnet’s?)
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.
b. You might have jotted down something like this.
c. Compass points north south with magnet. Needle follows magnet’s magnetic field lines. Bar magnet’s magnetic field is stronger than Earth’s at this spot. Did you move magnet gradually away from bar magnet? How far did it move before the Earth’s magnetic field took over? If not, do this now. What are your observations?
D. Place second sheet of paper over two bar magnets laying end to end vertical to north-south compass line. Strings taped to two magnets (north end of one, south end of other) should extend past either edge of covering paper. VERY CAREFULLY shake iron filings from their container onto paper above magnets. What do you see? Quickly write down your explanation. Is a magnetic field only two-dimensional? What do you think? What is a magnetic field? Take a quick guess. Carefully, slowly, pull the two magnets apart using the strings taped to the magnets. Add more iron filings if you must. What happens to the iron filings?
a. [Author’s Note: Place these notes after each exploration in separate place so students can check when they’re done.
b. You might have jotted down something like this.
c. The iron filings showed the lines of the magnets’ magnetic fields. The two magnets make one long magnet. But when pulled apart the iron filings appear to show three separate magnetic fields around and between two magnets.

Conclusion: Ideas to Consider
Thinking about magnetism, putting ideas together, adding a few new ideas, asking two key questions, and moving along on our journey.

• Question #1: What makes life on board the space station dangerous?
• Question #2: What do I have to learn as a Mission Specialist, so I can help keep Space Station Alpha safe for the astronauts?

A magnet has a magnetic field. The Earth has a magnetic field. There are magnetic fields all around us. Compasses will point along the magnetic field lines of the closest, strongest magnetic field. The force of a magnetic field is indirectly related to its distance from the object. Metal objects, such as metal filings, if scattered on paper above a magnet will follow the lines of a magnetic field. The poles of two magnets attract if they are different and repel if they are the same. A magnetic force attracts some objects, especially those made of metal, and has no effect on other objects.

Magnetic fields are real, even though they are invisible, and different objects such as little magnets and big planets can create them. The bar magnet was iron. Our earth-magnet has an iron core. Some metals such as iron, nickel, and cobalt, have extra electrons spread around through the metals that make them ideal candidates for creating a magnetic field. Now hold on to your brain for this next idea: for some elements, if a nucleus is spinning at a very, very high rate of speed, the spinning nucleus creates a magnetic field! So do the electrons! The sun, has no iron in it. Does it have a magnetic field? Yes! The sun has no iron at its core and still has magnetic fields! Do the Sun’s magnetic fields affect life on board the Space Station? The answer to this question is important to Mission Specialists.

Scientists discovered that they could move wires across magnetic fields to induce (start it flowing) electricity in the wires. They learned also that the electricity flowing in wires induces magnetism in nearby metallic objects. These experiments demonstrated that there is a close relationship between electricity and magnetism. Electricity can be used to create magnetism and vice versa. Does this have anything to do with the sun’s ability to create x-rays, gamma rays, ultraviolet rays, light rays, and microwaves? We know the sun produces ultraviolet rays because of all the advertisements we see about protecting ourselves from sunburn with sunscreens. Does the sun produce rays that are more dangerous to the astronauts that may follow the lines of the Sun’s and Earth’s magnetic fields?

What is most interesting, and of great concern to the astronauts on Space Station Alpha is the fact that, just like the iron filings, dangerous high-energy wave/particles (photons), namely x-rays and gamma rays, tend to follow magnetic field lines as well.

Don’t forget to return all the exploratory materials safely back to your teacher. Clean your desks. And SAVE your notes on magnetism.