How do magnetism work

These particles become tiny magnets, each with north and south poles. Technically, all matter is subject to the magnetic forces that pervade our universe. Some of these effects are more obvious than others, according to the BBC. Have you checked twitter today?

Driven in a car? Binged a new show lately? The world we live in is powered by these electromagnets. Often, the magnetic fields generated by these particles are random, meaning their north and south poles cancel each other out.

Some objects—from hunks of iron ore to the alphabet magnet stuck to your fridge—have magnetic fields that are arranged in the same direction. The magnetic fields of these objects become stronger as the velocity of these electrically charged particles increases, according to Live Science.

Magnetism is a mysterious force in this universe. These objects become permanently magnetized, through a process called hysteresis. Early iron compass needles were magnetized by lodestone, or magnetized magnetite minerals, pulled from the Earth. This is the only magnetic force that humans can tangibly feel. Ferromagnetism may be the most noticeable form of magnetism, but electromagnetism is arguably the most important.

Electricity and magnetism are closely intertwined, and their respective fields feed off of and interact with one another. Every electron generates a magnetic field, but they only generate a net magnetic field when they all line up.

Otherwise, the electrons in the human body would cause everyone to stick to the refrigerator whenever they walked by, Walker said. Currently, physics has two explanations for why magnetic fields align in the same direction: a large-scale theory from classical physics, and a small-scale theory called quantum mechanics.

According to the classical theory, magnetic fields are clouds of energy around magnetic particles that pull in or push away other magnetic objects. But in the quantum mechanics view, electrons emit undetectable, virtual particles that tell other objects to move away or come closer, Walker said. Although these two theories help scientists understand how magnets behave in almost every circumstance, two important aspects of magnetism remain unexplained: why magnets always have a north and south pole , and why particles emit magnetic fields in the first place.

We don't really know why. This forms the magnetic domains discussed in the previous section. You may have noticed that the materials that make good magnets are the same as the materials magnets attract. This is because magnets attract materials that have unpaired electrons that spin in the same direction. In other words, the quality that turns a metal into a magnet also attracts the metal to magnets. Many other elements are diamagnetic -- their unpaired atoms create a field that weakly repels a magnet.

A few materials don't react with magnets at all. This explanation and its underlying quantum physics are fairly complicated, and without them the idea of magnetic attraction can be mystifying.

So it's not surprising that people have viewed magnetic materials with suspicion for much of history. You can measure magnetic fields using instruments like gauss meters , and you can describe and explain them using numerous equations. Here are some of the basics:. Every time you use a computer, you're using magnets.

A hard drive relies on magnets to store data, and some monitors use magnets to create images on the screen. If your home has a doorbell , it probably uses an electromagnet to drive a noisemaker.

Magnets are also vital components in CRT televisions , speakers , microphones , generators, transformers, electric motors , burglar alarms , cassette tapes, compasses and car speedometers. In addition to their practical uses, magnets have numerous amazing properties. They can induce current in wire and supply torque for electric motors.

A strong enough magnetic field can levitate small objects or even small animals. Maglev trains use magnetic propulsion to travel at high speeds, and magnetic fluids help fill rocket engines with fuel. The Earth 's magnetic field, known as the magnetosphere , protects it from the solar wind. According to Wired magazine, some people even implant tiny neodymium magnets in their fingers, allowing them to detect electromagnetic fields [Source: Wired ].

Magnetic Resonance Imaging MRI machines use magnetic fields to allow doctors to examine patients' internal organs. Doctors also use pulsed electromagnetic fields to treat broken bones that have not healed correctly.

This method, approved by the United States Food and Drug Administration in the s, can mend bones that have not responded to other treatment. Similar pulses of electromagnetic energy may help prevent bone and muscle loss in astronauts who are in zero-gravity environments for extended periods.

Magnets can also protect the health of animals. Cows are susceptible to a condition called traumatic reticulopericarditis , or hardware disease , which comes from swallowing metal objects. Swallowed objects can puncture a cow's stomach and damage its diaphragm or heart. Magnets are instrumental to preventing this condition. One practice involves passing a magnet over the cows' food to remove metal objects.

Another is to feed magnets to the cows. Long, narrow alnico magnets, known as cow magnets , can attract pieces of metal and help prevent them from injuring the cow's stomach. The ingested magnets help protect the cows, but it's still a good idea to keep feeding areas free of metal debris. People, on the other hand, should never eat magnets, since they can stick together through a person's intestinal walls, blocking blood flow and killing tissue. In humans, swallowed magnets often require surgery to remove.

Some people advocate the use of magnet therapy to treat a wide variety of diseases and conditions. According to practitioners, magnetic insoles, bracelets, necklaces, mattress pads and pillows can cure or alleviate everything from arthritis to cancer. Some advocates also suggest that consuming magnetized drinking water can treat or prevent various ailments.

Proponents offer several explanations for how this works. One is that the magnet attracts the iron found in hemoglobin in the blood , improving circulation to a specific area. Another is that the magnetic field somehow changes the structure of nearby cells. However, scientific studies have not confirmed that the use of static magnets has any effect on pain or illness. Clinical trials suggest that the positive benefits attributed to magnets may actually come from the passage of time, additional cushioning in magnetic insoles or the placebo effect.

In addition, drinking water does not typically contain elements that can be magnetized, making the idea of magnetic drinking water questionable. Some proponents also suggest the use of magnets to reduce hard water in homes. According to product manufacturers, large magnets can reduce the level of hard water scale by eliminating ferromagnetic hard-water minerals.

However, the minerals that generally cause hard water are not ferromagnetic. A two-year Consumer Reports study also suggests that treating incoming water with magnets does not change the amount of scale buildup in a household water heater.

Even though magnets aren't likely to end chronic pain or eliminate cancer , they are still fascinating to study. A magnet can have multiple north and south poles, and these poles always occur in pairs. There can be no north pole without a corresponding south pole, no south pole without a corresponding north.

Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Physical Science. How Magnets Work. Iron filings beautifully show off the opposing fields of the same poles of two bar magnets. Iron filings right align along the magnetic field lines of a cylindrical neodymium magnet. Iron filings right align along the magnetic field lines of a cubical neodymium magnet.

Ceramic magnets , like the ones used in refrigerator magnets and elementary-school science experiments, contain iron oxide in a ceramic composite.

Most ceramic magnets, sometimes known as ferric magnets, aren't particularly strong. Alnico magnets are made from aluminum, nickel and cobalt. They're stronger than ceramic magnets, but not as strong as the ones that incorporate a class of elements known as rare-earth metals.

Neodymium magnets contain iron, boron and the rare-earth element neodymium. Samarium cobalt magnets combine cobalt with the rare-earth element samarium. In the past few years, scientists have also discovered magnetic polymers , or plastic magnets. Some of these are flexible and moldable. However, some work only at extremely low temperatures, and others pick up only very lightweight materials, like iron filings.

Making Magnets: The Basics " ". In an unmagnetized ferromagnetic material, domains point in random directions.