MAGNETISM Many people believe magnets merely hold pieces of paper up on the fridge and do not realise the importance of magnets in our lives today. But the impact that magnetism has had on society today is far reaching. The "simple" magnet has led to great scientific discoveries including that of electromagnets which are found everywhere in day to day life. This report looks at the history of magnetism by describing how the understanding of magnetic theories has developed over time, and the impact it has had on society and scientific thinking today. Humans have known about magnets since the ancient times but it has not been until several hundred years ago that magnetism began to be scientifically studied. Since 600 B.

C, the Greeks and Chinese used hard black stones called Lodestones to attract iron objects. But it was not until the 1200 s (AD) that a Frenchman called Petrus Peregrines began to study magnetism. His studies helped us understand how magnets work. Because all substances are made up of atoms that are freely floating around, when a magnet comes within range the atoms become magnetised meaning they are pulled into organised rows.

This is because each atom has a moving cloud of spinning electrons around it which creates an invisible magnetic field. Therefore the magnets created, are polarised. A magnet has a north and south pole. Atoms also have a north and a south pole.

Opposite poles (north and south) attract and like poles (north and north, or south and south) repel. A piece of magnetised iron will attract a piece of unmagnetised iron (e. g. an ordinary nail) because the magnetism causes a growth in size of the Magnetic domains (clusters of aligned atoms) that are oriented in the direction of the magnetic field. When the nail is pulled off the magnetised iron the domains will return to the random arrangement. Why magnets attract other objects was not understood until 1925 when two American physicist, Samuel Abraham Goudsmit and George Eugene Uhlenbeck showed that electrons spin..