Page 28 - FOUNDATIONS FOR LIFE; EXPLORING GOD’S UNIVERSE

Science Y6 – Forces and Motion – week 2

Magnets and Lodestones (Creative Kinds at Home web page)

Lodestones are magnets that are found in nature. They are chunks of magnetite ( Fe3O4 ) that have been
exposed to the strong magnetic field from a bolt of lightning that has struck the earth. As early as 800BC,
both the Chinese and the Greeks have known about how pieces of iron will stick to lodestone. There are
references by the Greek historian Pliny to a herdsman named Magnes, who found that his iron shod staff stuck
to some of the stones where his herd grazed. Ancient Egyptians referred to lodestone as the bone of Haroeri,
grandson of the goddess of the earth.

Lodestones and Compasses

One of the earliest known recorded use of a compass is from China. There are records in ancient texts dating
from approximately 100AD of a “South Pointer”. This device was a lodstone spoon that was balanced on a
plate. The cup part of the spoon would point south, giving the Emperor the direction he needed so that he could
plough a ritualistic furrow to ensure the fertility of the earth.

There is also evidence of compasses being used in the laying out of some very old cities in the south of China.
For example, in the city of Kansu, there are traces of two different alignments. In the older part of the city,
the alignment runs almost North/South - in a newer section of the city the alignment runs 11 degrees to the
east of North/South. See some old pictures of this city.

Once the properties of magnets were explored more, compasses were developed. This allowed for much
greater exploration of the planet. In 1492, Columbus used a compass to allow his ships to continue on their
westward course on his quest to find India. Unfortunately Columbus found that the Americas were in the way.

Magnets Today

In today’s world magnets can be found everywhere. Wherever there is an electric motor such as in a fan, or an
electric generator you will find magnets. Every wire that has electricity running through it will also have its own
magnetic field around it. You can use this magnetic field to create an electro magnet of your own.

Maglev trains are one of the flashiest uses of magnets in today’s world. These trains have powerful magnets
underneath them and these magnets lift the train up off of the track. With no contact to the earth, these trains
can move incredibly fast and provide a very smooth ride for the passengers. Find out more about Maglev
trains.

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