Unit 11 Module 1: Magnets

What IS magnetism, anyway? You can feel how two north sides of a magnet push against each other, but what IS that invisible force, and why is it there? And how come magnets stick to the fridge and not a soda can? We’ll about to dive deep into the mysterious world of magnetism. Although scientists are still trying to puzzle out some of its secrets, I’m going to get you up to speed on what they do know today. Are you ready?

Why do magnets stick together? And why does breaking one in half create a new set of poles? We're going to explore these and other weird things about magnets. Are you ready? This video will get you started on the right foot for your study into with oddball world of magnets as you detected the earth's magnetic pulse, discover magnetic levitation, uncover weird eddy currents that counteract gravity, and discover how a grape is magnetic. Let's get started:

You can get started by watching this video, and afterward either read more about it or start your experiments!

Scientific Concepts:

Magnetic fields are created by electrons moving in the same direction.
Electrons can have a “left” or “right” spin.
If an atom has more electrons spinning in one direction than in the other, that atom has a magnetic field.
If an object is filled with atoms that have an abundance of electrons spinning in the same direction, and if those atoms are lined up in the same direction, that object will have a magnetic force.
There’s still a lot about fields that is unknown. Fields are an exciting area of physics where a lot is still left to be discovered.
A field is an area around a electrical, magnetic or gravitational source that will create a force on another electrical, magnetic or gravitational source that comes within the reach of the field.
In fields, the closer something gets to the source of the field, the stronger the force of the field gets. This is called the inverse square law.
A magnetic field must come from a north pole of a magnet and go to a south pole of a magnet (or atoms that have turned to the magnetic field.)
All magnets have two poles. Magnets are called dipolar which means they have two poles.
The two poles of a magnet are called north and south poles.
The magnetic field comes from a north pole and goes to a south pole.
Opposite poles will attract one another. Like poles will repel one another.
Iron and a few other types of atoms will turn to align themselves with the magnetic field.
The Earth has a huge magnetic field.
The Earth has a weak magnetic force.
The magnetic field probably comes from the moving electrons in the currents of the Earth’s molten core.
The Earth has a north and a south magnetic pole which is different from the geographic north and south pole.
Compasses turn with the force of the magnetic field.
Over time iron atoms will align themselves with the force of the magnetic field.

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	Special Science Teleclass: Magnetism This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! Discover how to detect magnetic fields, learn about the Earth’s 8 magnetic poles, and uncover the mysterious link between electricity and magnetism that marks … Continue reading "Special Science Teleclass: Magnetism"
	Which way is North? I can still remember in 2nd grade science class wondering about this idea. And I still remember how baffled my teacher was when I asked her this question: “Doesn’t the north tip of a compass needle point to the south pole?” Think about this – if you hold up a magnet by a string, just … Continue reading "Which way is North?"
	Bouncing Magnets Want to see a really neat way to get magnetic fields to interact with each other? While levitating objects is hard, bouncing them in invisible magnetic fields is easy. In this video, you’ll see how you can take two, three, or even four magnets and have them perform for you. Are you ready? Materials: 3 … Continue reading "Bouncing Magnets"
	Magnetic Fields This is a quick and simple experiment to answer the question of magnetic field strength: Do four magnets have a stronger magnetic pull than one? You’ll find the answer quite surprising… which is: it depends. Here’s what you need to do to see for yourself:
	Magnetic Sensors Wouldn’t it be cool to have an alarm sound each time someone opened your door, lunch box, or secret drawer? It’s easy when you use a reed switch in your circuit! All you need to do it substitute this sensor for the trip wire and you’ll have a magnetic burglar alarm. The first thing you … Continue reading "Magnetic Sensors"
	Magnet Boats We took our first step into the strange world of magnetism when we played with magnetizing a nail. We learned that magnets do what they do because of the behavior of electrons. When a bunch of those crazy little guys get going in the same direction they create a magnetic field. So what’s a magnetic … Continue reading "Magnet Boats"
	Simple Magnet Experiments Let’s play around with the idea of lining up all the mini-magnets inside an object to magnetize it. You’ll need a steel nail (steel is a combination of iron and carbon), a magnet (the stronger the better), and a few paper clips. Here’s what you do:
	Magnetic Grape Every atom has electrons, and electrons both go around the core and also spin. Depending on how they spin and how much energy the atom has will determine what kind of magnetic properties your atom will have. Iron is ferromagnetic, which means it’s attracted to both poles of a magnet – bring a nail close … Continue reading "Magnetic Grape"
	Ferrofluid A ferrofluid becomes strongly magnetized when placed in a magnetic field. This liquid is made up of very tiny (10 nanometers or less) particles coated with anti-clumping surfactants and then mixed with water (or solvents). These particles don’t “settle out” but rather remain suspended in the fluid. The particles themselves are made up of either … Continue reading "Ferrofluid"
	Eddy Currents and Magnetic Brakes Eddy currents defy gravity and let you float a magnet in midair. Think of eddy currents as brakes for magnets. Roller coasters use them to slow down fast-moving cars on tracks and in free-fall elevator-type rides. Here’s what you need to do this activity:
	Curie Heat Engine Magnetic material loses its ability to stick to a magnet when heated to a certain temperature called the Curie temperature. The Curie temperature for nickel is 380 oF, iron is 1,420oF, cobalt is 2,070 oF, and for ceramic ferrite magnets, it starts at 860oF. We’re going to heat a magnet so that it loses temporarily … Continue reading "Curie Heat Engine"
	Linear Accelerator There are two ways to create a magnetic field. First, you can wrap wire around a nail and attach the ends of the wire to a battery to make an electromagnet. When you connect the battery to the wires, current begins to flow, creating a magnetic field. However, the magnets that stick to your fridge … Continue reading "Linear Accelerator"

Scientific Concepts:

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