Have you ever heard the phrase opposites attract? This concept is well demonstrated by a simple
pair of magnets. Flip them one way and they snap together, but turn them over and suddenly they
push away from each other. This happens because every magnet has a north pole and a south pole,
and opposites attract. The north pole of one magnet will attract the south pole of
another magnet. But put two north poles or two south poles together and the magnets repel each
other. However, magnets aren't just for hanging your artwork on the refrigerator. Magnets are an
integral and necessary component of our modern world. The first magnets ever discovered were
a type of natural magnet called lodestone or magnetite. Long ago, people discovered
that lodestone would always point north. This discovery led to the invention of early
compasses. Compasses work because the Earth is, in a way, a giant magnet with its own magnetic
north and south pole. The design of the compass has changed very little over thousands of years
and compasses are still used for navigation and location purposes today In today's world,
the use of magnets is still fascinating. This impressive-looking machine is called an MRI
or magnetic resonance imaging device. It is a non-invasive way for doctors to get a look at what
is happening inside a patient's body. An MRI uses a strong magnetic field along with radio waves to
produce clear images of tissues and organs inside the body. Because magnets are used in
these machines and metal is attracted to magnets, people who have implants that have metal in them
like pacemakers or Cochlear implants cannot have an MRI. Magnets are also responsible for
some of the fastest trains in the world. This maglev train has no wheels or rails.
Maglev is short for magnetic levitation. Instead of wheels, a set of strong magnets
along the bottom of the train and another set on the track repel each other and lift the train up
so it levitates or floats above the track. Other magnets move the train forward or backward. With
no friction from wheels, these trains can move at amazing speeds up to 375 miles per hour.
This junkyard is using a special kind of magnet called an electromagnet to separate
valuable metal scraps from the rest of the garbage. It also uses the magnet to move
large items around. An electromagnet uses electricity to create a strong
magnetic pull that can be turned on and off. Electromagnets are a huge part of the everyday
life. You can find them in anything that has a motor from cars to power tools,
from TVs to elevators. You can even find them in commonplace items like headphones, doorbells,
and computers. Humans find so many ways to put magnets to use from the magnet that holds your
refrigerator shut to the magnetic screwdriver that can hold its own screws. Electromagnets
power your car as it drives down the road and help produce the music that comes out of your
radio speakers. Everywhere you look, it's clear that we all live in a magnetic world.