Why do magnets stick together

When touching, however, it is equal to Pull Force Case 1. Using magnets to repel each other is one way to try to achieve a frictionless bearing. In practice, it can be difficult to remove all friction. While a pair of magnets will repel each other, they are not stable in this condition. One magnet won't simply float forever above another magnet. The picture on the product page for our RX magnet illustrates this point.

It shows one ring magnet floating over another, with one key detail: The pencil sticking through their holes provides the needed stability. You might mimic this setup in your own levitation projects. But what about if I add another magnet in another position, to make a magnetically stable "pocket" for the floating one to sit in? Sorry, it doesn't work that way. As you add more and more magnets, the magnetic fields interact in complex ways that are hard to summarize with simple rules of thumb.

What's more, Earnshaw's theorem states that no matter what way you orient the magnets, you can't make it stable with stationary magnets alone. See the section in that article about loopholes if you're trying to get around this!

When considering the repelling force between two magnets, you must consider the distance between them. The farther two magnets are apart from each other, the weaker the repulsion force will be. Our Repelling Force Magnet Calculator offers a way to quantify these forces online. For example, a pair of RX magnets will repel each other with about 25 lb when touching, but only 5. A steel object such as a screwdriver can retain a small amount of magnetism after a neodymium magnet is taken away.

It won't last forever, but you can temporarily magnetize it. Here's how:. For example:. Many of today's electronic devices require magnets to function. This reliance on magnets is relatively recent, primarily because most modern devices require magnets that are stronger than the ones found in nature. Lodestone , a form of magnetite , is the strongest naturally-occurring magnet. It can attract small objects, like paper clips and staples.

By the 12th century, people had discovered that they could use lodestone to magnetize pieces of iron, creating a compass. Repeatedly rubbing lodestone along an iron needle in one direction magnetized the needle.

It would then align itself in a north-south direction when suspended. Eventually, scientist William Gilbert explained that this north-south alignment of magnetized needles was due to the Earth behaving like an enormous magnet with north and south poles.

A compass needle isn't nearly as strong as many of the permanent magnets used today. But the physical process that magnetizes compass needles and chunks of neodymium alloy is essentially the same. It relies on microscopic regions known as magnetic domains , which are part of the physical structure of ferromagnetic materials , like iron, cobalt and nickel. Each domain is essentially a tiny, self-contained magnet with a north and south pole.

In an unmagnetized ferromagnetic material, each of the north poles points in a random direction. Magnetic domains that are oriented in opposite directions cancel one another out, so the material does not produce a net magnetic field. In magnets, on the other hand, most or all of the magnetic domains point in the same direction. Rather than canceling one another out, the microscopic magnetic fields combine to create one large magnetic field.

The more domains point in the same direction, the stronger the overall field. Each domain's magnetic field extends from its north pole into the south pole of the domain ahead of it.

This explains why breaking a magnet in half creates two smaller magnets with north and south poles. It also explains why opposite poles attract -- the field lines leave the north pole of one magnet and naturally enter the south pole of another, essentially creating one larger magnet.

Like poles repel each other because their lines of force are traveling in opposite directions, clashing with each other rather than moving together. To make a magnet, all you have to do is encourage the magnetic domains in a piece of metal to point in the same direction. That's what happens when you rub a needle with a magnet -- the exposure to the magnetic field encourages the domains to align. Other ways to align magnetic domains in a piece of metal include:.

Two of these methods are among scientific theories about how lodestone forms in nature. Some scientists speculate magnetite becomes magnetic when struck by lightning. Others theorize that pieces of magnetite became magnets when the Earth was first formed. The domains aligned with the Earth's magnetic field while iron oxide was molten and flexible. The most common method of making magnets today involves placing metal in a magnetic field.

The field exerts torque on the material, encouraging the domains to align. There's a slight delay, known as hysteresis , between the application of the field and the change in domains -- it takes a few moments for the domains to start to move. Here's what happens:. The resulting magnet's strength depends on the amount of force used to move the domains. Its permanence, or retentivity , depends on how difficult it was to encourage the domains to align.

Materials that are hard to magnetize generally retain their magnetism for longer periods, while materials that are easy to magnetize often revert to their original nonmagnetic state. You can reduce a magnet's strength or demagnetize it entirely by exposing it to a magnetic field that is aligned in the opposite direction. You can also demagnetize a material by heating it above its Curie point , or the temperature at which it loses its magnetism.

The heat distorts the material and excites the magnetic particles, causing the domains to fall out of alignment. Large, powerful magnets have numerous industrial uses, from writing data to inducing current in wires.

But shipping and installing huge magnets can be difficult and dangerous. Not only can magnets damage other items in transit, they can be difficult or impossible to install upon their arrival. In addition, magnets tend to collect an array of ferromagnetic debris, which is hard to remove and can even be dangerous. For this reason, facilities that use very large magnets often have equipment on site that lets them turn ferromagnetic materials into magnets.

Often, the device is essentially an electromagnet. If you've read How Electromagnets Work , you know that an electrical current moving through a wire creates a magnetic field. Moving electrical charges are responsible for the magnetic field in permanent magnets as well. But a magnet's field doesn't come from a large current traveling through a wire -- it comes from the movement of electrons. Many people imagine electrons as tiny particles that orbit an atom's nucleus the way planets orbit a sun.

As quantum physicists currently explain it, the movement of electrons is a little more complicated than that. Essentially, electrons fill an atom's shell-like orbitals , where they behave as both particles and waves. The electrons have a charge and a mass , as well as a movement that physicists describe as spin in an upward or downward direction.

You can learn more about electrons in How Atoms Work. Generally, electrons fill the atom's orbitals in pairs. Stephen G Bosi does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

This is an article from Curious Kids , a series for children. All questions are welcome — serious, weird or wacky! Hi my name is Dean and I am 7 years old. My question is: How and why do magnets stick together?

Every magnet has two sides: a north pole and a south pole. If you hold two magnets the wrong way around, they push apart - they repel!

In other words, if you hold two magnets together so that like-poles are close together two norths OR two souths , they repel. Try it! It feels like the magnets are surrounded by an invisible rubber layer pushing them apart. This is similar to electric charges. Like charges repel, and unlike charges attract. Since a free hanging magnet will always face north, magnets have long been used for finding direction. Thousands of years ago Chinese sailors used a magnetized needle floating in water to tell direction.

This made a simple kind of compass. Columbus as well as other explorers also used magnetic needles as a compass to help them across the Atlantic Ocean. The earth is like a giant magnet, but unlike two free hanging magnets, the north pole of a magnet is attracted to the north pole of the earth.

The earth is the biggest magnet on the earth itself. It is made up of mostly iron and nickel. The outer core is made up of melted, molten rock, which has metal in it. The center or inner core of the earth is made up of metal too. When the inner core moves against the outer core, this makes earth turn into one huge magnet. Introduce lesson by reviewing what we already know about magnets. Give each pair an experiment sheet to complete.