Magnetism

Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. All materials are influenced to some extent by a magnetic field. The strongest effect is on ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves.

History of Magnetism

The history of magnetism dates back to earlier than 600 BC. The Ancient Greeks were aware of this property, which they discovered in naturally occurring lodestone.

Types of Magnetism

There are several types of magnetism, including:

• Ferromagnetism
• Antiferromagnetism
• Diamagnetism
• Paramagnetism
• Superparamagnetism

Magnetic Fields

A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials.

Magnetic Moments

The magnetic moment is a quantity that represents the magnetic strength and orientation of a magnet or other object that produces a magnetic field.

Applications of Magnetism

Magnetism has many applications in modern life. These include:

• Magnetic storage media
• Magnetic resonance imaging
• Magnetic levitation
• Magnet therapy

See Also

• Electromagnetism
• Magnetoreception
• Geomagnetism

References

• Metal shavings around bar magnet (close-up)
  Metal shavings around bar magnet (close-up)
• 
  Lodestone attracting nails
• Blacksmith at the anvil
  Blacksmith at the anvil
• A man is violently rubbed with magnets
  A man is violently rubbed with magnets
• 
  Magnetism
• Magnetic Domains 2
  Magnetic Domains 2
• Magnetic Domains 3
  Magnetic Domains 3
• 
  Antiferromagnetic ordering
• 
  Ferrimagnetic ordering
• Magnetic orders
  Magnetic orders
• Electromagnet
  Electromagnet
• 
  Magnet