The little ornaments holding pictures to your refrigerator and the giant cranes picking up cars in a junkyard are all using magnets. Magnets attract objects made of certain metals. They can also push away, or repel, other magnets.
The Mini Page talked with an expert from the National Science Foundation to learn more about this force of attraction.
Matter is the stuff all around us: people, animals, paper clips, magnets, air and this paper you’re reading. Matter is made up of tiny atoms, which are made up of even tinier particles: protons, electrons and neutrons.
Protons have a positive charge, and electrons have a negative charge. (Neutrons have no charge.)
Magnetism is closely related to electricity. Scientists often refer to the two forces together as electromagnetism.
Magnetism comes from moving electrical charges. An electrical current running along a wire produces magnetism.
It works the other way too. If a wire is moved near a magnet, the magnetic force produces an electrical current. It makes electrical charges move.
A pole is the area in a magnet where the magnetism is the strongest. A magnet always has two opposite poles, a south pole and a north pole. The south pole is at one end, and the north pole is at the other.
Like, or similar, poles repel each other, and opposite poles attract each other. The south pole in one magnet attracts the north pole in another magnet. The south poles of two magnets repel each other. The north poles of two magnets also repel each other.
When magnetic forces from the sun and the Earth cross, they create a great burst of energy. NASA plans to launch four spacecraft in the fall of 2014 to study this system, in the Magnetospheric Multiscale (MMS) mission.
Technology called magnetic resonance imaging, or MRI, can take special pictures of the insides of our bodies, as with this person’s brain. An MRI machine surrounds the patient with magnets, producing conditions that allow experts to see what’s going on inside.