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IT’S A KIND OF MAGIC
A lodestone
attracting nails
Photo: Teravolt
It’s all because of what we call
electromagnetism. Once scientists
would have said that magnetism
was the strange, invisible force of
attraction between certain materials
- today, we can explain it as a
force created by either magnets, or
electricity.
People have known about magnets
for thousands of years. The ancient
Greeks and Romans knew that
lodestone (an iron-rich mineral) can
attract other pieces of iron to it, while
the ancient Chinese were making
magnetic compasses hung on strings.
Sailors also used to use the lodestone
and a magnetic needle that swung
on a point although they believed
it worked by magic! In those days
no-one knew about how a magnet’s
structure causes its magnetic
properties.
One of the most amazing things
about magnets is the way they can
attract other magnets (or other
magnetic materials) "at a distance",
invisibly, through what we call
a magnetic field. A giant storm
travelling from the sun was pushed
away from the Earth because our
planet’s magnetic field did the
pushing.
Small planet Earth, on the right, is protected from the
storm by magnetic field lines shown in blue and purple.
(In reality, the sun is much further away than this.)
WATCH A VIDEO OF A
MAGNET EXPERIMENT:
http://tinyurl.com/zlrtqq8
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