This presentation of magnetism has been assembled to help aid in teaching the concepts of magnetism to classes between grades 8 and 12. No equations have been used and the main concepts are described though the demonstrations.

The materials for this presentation can be ordered for usage, by contacting the UBC Physics & Astronomy Outreach Program or the materials can be assembled for less than $200, by using items found at the hardware store, grocery store, and science teacher websites (such as Educational Innovations ).

List of items in the presentation:

8 red/blue ceramic magnets
1 30 x 30 cm magnetic field viewer film
6 15 x 15 cm magnetic field viewer films
1 eddy current tube (1 m x 2.5 cm ID copper pipe with 2.5 cm wide strip of magnetic viewing film)
1 2.5 cm x 2.5 cm cylindrical stainless steel
1 2.5 cm x 2.5 cm cylindrical neodymium magnet
1 odd shaped neodymium magnet
1 2 cm spherical neodymium magnet
1 2.5 cm disk neodymium magnet
100 1 cm disk neodymium magnets
1 8 x 8 cm copper coil (100 turns)
1 9 volt battery
1 floating ring magnet set
1 levitron top (very difficult to master)
1 lodestone
1 500 ml of olive oil
1 9 cm cork disk
2 3 cm compasses
2 2D magnetic field viewers (made of 2 salad container tops with a tea spoon of iron filings inbetween)
1 3D magnetic field viewer (made of 1 clear rectangular container filled with baby oil and 2 tea spoons of iron filings)
1 container of iron filings
1 package of overheads of the pictures used in the presentation

Please Note:

The larger neodymium magnets are extremely strong, caution must be heeded as they are capable of bone crushing forces!

Pass out a couple of magnets (blue/red or the 1 cm disk neodymium magnets) for self exploration.

Definition of a Magnet
- OBJECT: Piece of metal that attracts metal. A piece of metal that has the power to draw iron or steel objects toward it and to hold or move them (msn Encarta).

Definition of Magnetism
- ACTION: The force exerted by a magnet. The phenomenon of physical attraction for iron, inherent in magnets or induced by a moving electric charge or current.
- Force of magnetic field: the force exerted by a magnetic field (msn Encarta).

This is the coolest demonstration of the presentation's collection.

- Click on the image to play the movie clip.

- Start with the magnetic viewing film not showing.
- Ask the class how fast objects fall due to gravity (9.8 m/s). Objects should fall though the tube (1 m) in less than 1 sec.
- Drop the stainless cylinder through the tube to confrim this fact.
- Before droping the neodymium cylinder: ask the class whether it drops faster, slower or stops through the tube, then drop it. It will take about 9 secs to fall.
- Ask why the magnet might move slower through the tube (remember gravity affects ALL OBJECTS equally) and the copper tube is not paramagnetic (uneven spins, which permanent magnetic material must have) but diamagnetic (paired spins).
- Try different magnets, each one will have a different magnetic shadow and fall at different times.: sphere: 4 sec., disk: 16 sec., odd shape: 3 sec.
- Ask why the different magnets might fall through the tube at different times (It has to do with shape and size). The tighter the fit in the tube the slower it will travel through it.
- Also notice that instead of the magnets falling at a constant acceleration, they are falling with nearly constant velocity, which means a repelling force is involved which is negating the force of gravity.
- More principles of magnetism need to be explored before an answer can be fully formulated.

Pass out magnet and viewing film.

- The magnets handed out can be either the red/blue or the 1 cm disk neodymium magnets.
- The magnetic viewing will not show a shadow for any other material, it only works with magnetic materials.
- It is similar to iron filings in a gel, wrapped in two sheets of plastic.
- Please note: The film is not transparent and will not show up on the overhead.

Iron (26)

Iron is the most common metal used for making magnets. It is abundant and easy to magnetize.

Yes, its called Lodestone or Magnetite.

Pass out the lodestone. Notice the iron filings that stick to it.

Use the compass to find the rock's North and South pole.

Place the rock on the magnetic viewing film to see its magnetic shadow.

Lodestone is ferrimagnetic.

1. Electromagnetic

- When an electric current is passed through a wire, the current creates a magnetic field.
- The higher the current, the stronger the magnetic field created.
- The loops in the wire help focus and strengthen the field created by the current.
- Demonstate the coil on a piece of magnetic viewing film.

2. Super Conductive

Such magnets are used in MRIs.

The mouse and the large magnet can be used to show how magnets can be used for special effects, such as in movies, séances etc.
- Click on the image to play the movie clip.
- Demonstrate the mouse moving by placing a magnet under the table. Move the magnet under the mouse (rotate, turn etc) to see which way the mouse will move.

The magnetic top can be used to show how magnets can be used to push/pull (similar to the electromagnets of a Maglev), or how the idea of perpetual motion machines cannot exist (if the top cannot keep spinning indefinitely, which has the minimum of friction associated with it how can any other mechanism possibly be more efficient at using energy).
- Demonstration of this top requires much practise.

The lodestone would be placed on cork in a bowl of oil, where it would rotate until it was lined up with the Earth's magnetic field, showing the sailor's the direction of magnetic North.
- Click on the image to play the movie clip.
- Demonstrate the lodestone compass.

Their names are used for the measure of coils and capacitors respectively. This is the start of the era of electromagnetism.

Demonstrate the magnetic field lines with with the 2D viewer
- Before putting the 2D viewer over the magnet, try to spread the iron filings out by shaking the viewer lightly.
- Pass out the red/blue magnets and the 2D viewer.
- Ask the class if they know what the field lines look like when 2 magnets are placed pole to pole (North - South, North - North, etc).

Much of the explanation on how the eddy tube demo works has been covered in the above presentation; see if the class can come up with the solution.

Just like a current in a wire creates a magnetic force, the moving magnet creates a current in the copper pipe, which in turn creates a magnetic force in the opposite direction. Because the forces are in opposite directions, the magnet’s decent is slowed.

Ferro-fluid Photo

MIT: One inch wide drop of ferro-fluid on a glass slide atop a yellow post-it with a green card held up to reflect another colour. Three magnets are arranged beneath slide - Felice Frankel.

- From "Visions of Earth," National Geographic, November 2005

Aurora Borealis (Northern Lights)
- Occur when highly charged electrons from the solar wind interact with elements in the earth's atmosphere.
- They follow the lines of magnetic force generated by the earth and flow through the magnetosphere, a teardrop-shaped area of highly charged electrical and magnetic fields.
- All of the magnetic and electrical forces react with one another in constantly shifting combinations. These shifts and flows can be seen as the aurora’s "dance,"

- Both of these great photos of the Aurora Borealis were taken by Dick Hutchinson, and his website can be accessed by clicking on either picture.