Magnets

1
Magnets If your refrigerator is like mine, it is
covered by notes and pictures and drawings. But,
how do all of these things stick to the front of
my refrigerator? I bet you guessed! Magnets!
Lets investigate! Magnets are so neat, but
where did they come from? Well, magnets were
discovered thousands of years ago by the ancient
Chinese. These ancient people found a special
kind of rock in their fields. This rock could
pull small pieces of iron towards it and the iron
would stick to the sides of the rock like magic.
Well, it seemed like magic to the ancient
Chinese, but we know that what they really
discovered was a special rock called a lodestone.
This kind of rock acts just like our
refrigerator magnets. Today many magnets are
man-made by scientists. Magnets have been
around for a really long time, but what are they
and how do they work? A magnet is an object that
is able to pull other objects towards it. If the
object is pulled too close, it will stick to the
magnet. This pulling is called attraction.
Magnets are attracted to other magnets and some
metals like iron.
2
Just like the Earth, every magnet has two ends
called poles. One end of a magnet is called the
north pole and the other end is called the south
pole. If you put two magnets beside each other
on your desk, the north pole of one magnet will
try to stick to the south pole of the other
magnet. They are attracted to each other. But,
if you try to stick the south pole of one magnet
to the south pole of the other magnet, they will
push away from each other. The same thing will
happen if you try to stick the north pole of one
magnet to the north pole of the other magnet. If
magnets push away from each other, we say they
repel. Did you know that magnets are all around
you? In addition to the magnets on your
refrigerator, the following objects also contain
magnets chalkboard letters, paperclip holders,
cabinet door latches, toys that run on batteries,
and compasses.
3
Do you know what a compass is? Soon after the
ancient Chinese found the magnetic lodestone
rocks in their fields, they discovered that if
they rubbed a metal needle against a lodestone,
the needle would turn into a magnet. They then
discovered that if they tied a string around the
middle of the needle magnet and let it hang down
from their hand, one end of the needle always
pointed north and the other end always pointed
south. They had invented the compass! People
soon began to use compasses to travel from place
to place. By using compasses, people could
figure out in what direction they were headed.
Christopher Columbus used a magnetic compass to
cross the huge Atlantic Ocean and discover
America. Wow! Arent you glad that the Chinese
invented the compass? Christopher Columbus might
not have discovered America without it!