Magnetism

Engineers apply their understanding of the phenomenon of magnetism to create devices that help improve everyone’s quality of life.

Between lifesaving medical devices, advancements in computer technologies, more sophisticated robots and other specialized electronics, engineers use magnets to develop groundbreaking technologies.

Magnetism is the physical phenomenon produced through the motion of electric charged particles, like electrons. Magnetism is a force that has the ability to repel or attract objects that contain magnetic material, such as iron, nickel, cobalt and some alloys of rare earth metals. The strength of the magnetic force depends on the distance or the amount of charge.
 

Everything around us is made up of atoms, and each atom has electrons — particles that carry electric charges. Most objects around us have electrons that spin in random directions, however the electrons in magnets spin in the same direction. This results in the creation of a magnetic field.

All magnets produce a field that has both a north and south pole. The poles are the strongest parts of the magnet. By holding two magnets close to each other, you can actually feel the magnetic force and experience that opposite poles (north and south) attract each other whereas identical poles (north and north or south and south) repel each other.

Three types of magnets are categorized by their magnetism source:

• Permanent magnets emit a magnetic field without any external source of electric power or magnetism. They do not easily lose their magnetism.
• Temporary magnets rely on outside forces and become magnetized when they are around a stronger magnet. They will lose their magnetism gradually when the other magnet and magnetic field is removed.
• Electromagnets are created when an electric current passes through a coil with a metal core, which is known as a solenoid. The strength of the magnetic field depends on the number of loops in the coil and the strength of the current.

Engineers use magnets in many ways. When designing information storage devices for computers—including hard drives and flash drives—they use strong magnets to read or write information to the devices. We see this everyday in credit cards, computers, and zip disks. Magnets are also used in motors and acoustics. Aerospace engineers apply their understanding of magnetic fields to design satellites that withstand the effects of the Earth's strong magnetic field, which can affect a satellite's orientation around the planet and disrupt sensitive electronics.

Magnetism is a highly-studied phenomenon because engineers use it to create electrical energy. The relation between magnetism and electricity is a key concept in science, and is the source of most of the energy we use today. This relationship has led to the operation of movable parts in nearly every electrical device, the ability to generate electricity for our homes, the wherewithal to perform non-invasive medical procedures, and more. Electricity and magnetism affect every modern industry, from communication to entertainment, medicine, warfare and manufacturing.