Begin with the Exploration
Here you will rediscover an amazing property of magnets discovered by the Chinese and the Europeans just under a thousand years ago. All magnets line up along a North-South line.
Continue with the Exploration
Where you will find that two north poles will repel and two south poles will repel but a north pole and a south pole will attract.
This is the origin of the phrase like poles repel and unlike poles attract.
Finish the first part of this lesson with the Exploration
We can use the attraction and repulsion of magnets to model the structure of the earth's atmosphere.
The exploration of attraction and repulsion can be extended to magnets interacting edge to edge not pole face to pole face.
Up to now we've been using a simple model in which poles attract or repel. Now, here are some activities which require a more complicated model of magnetism. To understand magnetic oscillators you need to use the concept of magnetic fields.
Here are a few optional explorations which you can do to learn more about magnetism.
Circles of Magnetism snack, electric currents create magnetic fields.
Diamagnetism Snack, Besides ferromagnetism there are other forms of diamagnetism such as diamagnetism exhibited by sugar water inside grapes. Which are attracted to magnets.
Eddy Currents snack, When a magnet moves near a metallic conductor eddy currents flow in the metal and make it an electromagnet which exerts forces on the magnet.
Magnetic Lines of force snack iron filings, Iron filings line up with the magnetic field lines of magnets.
Magnetic Shielding, Iron and other ferromagnetic materials will interact with magnetic fields so that the fields go into the iron. The fields will thus not penetrate the iron and so the iron becomes a magnetic shield.
Strange Attractor, snack. A magnetic pendulum exhibits chaos. The pendulum is attracted to the magnets, people are attracted to this exhibit.
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Scientific Explorations with Paul Doherty
30 May 2000