The average person uses a lot of electricity in the many things they do every day. We are used to being able to turn on a light, watch the television, use our mobile devices, and stream music or videos. Because electricity is so much a part of our lives, we should know something about it.
You have probably played with magnets at least one time. When you did you probably noticed that the magnet pulled itself towards other objects.
You might have an example of this on your refrigerator with magnets sticking and holding pieces of paper or drawings. In these cases, you need the magnets to hold them up because some materials such as plastic or paper aren’t affected by the magnetic pull.
The mystery of magnets
While magnets might seem like magic, they aren’t. Most magnets are made up of the metal iron or another mix of metals that have lots of iron in it.
The “pull” of a magnet happens when each object has opposite polarity: a negative and a positive. When two objects have the same polarity (positive and positive) they “repel” or push each other away.
A majority of the magnets that we see are mainly man-made by using electricity. There are also a lot of different types of magnets including electromagnets, Air-core magnets, and permanent magnets.
However, on the Earth’s surface we find a lot of rocks that are naturally magnetic. These are called “lodestone” and throughout history people would rub them on iron to create a magnet. The rubbing process pulled all of the electrons so that they were in the same direction.
Our ancestors thought that this invisible force was some kind of magic, but we know it’s really science.
What is magnetism?
The definition of magnetism is an invisible field or force caused by the unique properties of certain materials. To understand this idea we have to know that in almost all objects, electrons spin around in random directions.
This includes your pencil, a regular rock, or even your computer. The randomness of the spinning of electrons cancel each other out over time. But magnets are a completely different story.
In their case, the molecules are positioned so that their electrons all spin the same direction. By lining the atoms up like this it creates two “poles” of a magnet: a North-seeking pole and a South-seeking pole.
The magnetic force of the North-seeking pole and a South-seeking pole creates a magnetic field around the magnet. You can test the field out by trying to push two North-seeking or two South-seeking poles together.
They “repel” or push each other away and as you try to push you see a gap between the ends. This is the magnetic field that is being created. If you switched them around with North and South poles facing each other, you would see that they are attracted together.
Our Earth is one big magnet
The Earth’s center is mostly made up of iron. The outer section of the core is liquid iron that spins and this action has turned our Earth into one big giant magnet.
Our north and south poles are positive and negative and this is incredibly useful for traveling and using a compass to find our way. Some bird and animals also use the magnetic field to navigate their migrations and in search of food and water.
The magnetic field created by the Earth protects us as well. The field extends beyond the Earth and into space. It’ presence repels the harsh and dangerous solar wind and radiation that constantly hits the Earth.
Without the magnetic field there might not be any life on Earth. While the magnetic field is invisible, you can see the reaction of the solar wind hitting the field in the Aurora Borealis.
Electric magnets and motors
People can make magnets by wrapping wire around an iron bar and then running electrical current through the wire. This process is called electromagnetism and magnets of all sizes and powers can be made.
Some of these magnets are super-magnets, so strong that they could lift a car off of the ground; and others are used for smaller applications. One of the most important uses today is the electric motor.
Fun Facts about magnetism
- If you want to “see” a magnetic field you can place iron filings around a magnet.
- The best metals or magnetic attraction include iron, nickel and cobalt.
- Reverse magnetism (north to north or south to south) is used in high speed trains.
- Many materials are not attracted to magnets or “conductive” and can include wood, plastic, and glass.
What is the definition of magnetism?
an invisible field or force caused by the unique properties of certain materials
What can you do to see a magnetic field that surrounds a magnet?
Use iron filings all around the magnet
How are manmade magnets created?
wrap wire around an iron bar and then running electrical current through the wire
What is at the center of the Earth that creates the Earth’s magnetic field?
Spinning liquid iron
Magnets can do what two actions?
attract and repel
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