Many people connect magnets in their minds to tiny items on a refrigerator or whiteboard, the guts of a compass, or perhaps a giant, red, horseshoe-shaped object used in cartoons. Many of us don’t know what makes up magnetic fields, or why they work, and believe that magnetism does not affect our daily lives. However, magnetism is essentially important, because electricity and magnetism are inseparable – they are two aspects of the same force. Magnets are everywhere – in fans, computers, washing machines, medical equipment, and have a large part in generating the electricity that comes into the home, enabling you to use your television, gaming system, refrigerators, and lights. Magnets quite literally light up our world, thanks to revolutionary scientists like Michael Faraday and Hans Christian Ørsted.Not to mention, we’re also on top of a giant magnet, as the Earth itself is geomagnetic and has a magnetic north and south pole, without which our atmosphere probably wouldn’t exist. They also enable the beautiful aurora to light up at the earth’s poles. Besides the Earth, the Sun, too, is a giant magnet, with huge, and more complicated magnetic forces that can cause the arch shape of many solar flares. Looking at our own solar system, there are most likely many other geomagnets in the universe, so it is rather impossible to know what the strongest one might be (a candidate for the strongest known magnet field in the universe is 20 trillion times more powerful than a refrigerator magnet).
Besides the world of the very large, the force also affects the world of the very small. According to the standard model of particle physics, the electromagnetic force is one of the four fundamental forces at work in the universe (the others being gravity, the strong force, and the weak force). Certain particles behave in the ways that they do in part because of magnetism. Matter appears in the universe in part due to this force.
If magnets have such an astounding effect on our lives, then what are they? A “magnet” usually refers to something with invisible magnetic fields, which contain positive and negative charges, repel likes and attract opposites. There are many different kinds of magnets, from “permanent” magnets, to “temporary” magnets, to electromagnets (which are largely man made), to superconducting magnets. But what is a magnetic field, then? The invisible force is created by unpaired electrons spinning in the same direction. The field’s strength is measured in gauss or tesla (with 10,000 gauss per tesla), and the magnetic lines of force are measured in webers. Field lines can be mapped like a topographic map of a mountain, and many of us have done this by using iron fillings on simple magnets with north and south poles.
Electricity and magnetism are related largely because they both relate to the movement and activity of electrons. For many years this fact eluded physicists, until Ørsted discovered that electric currents could affect a compass. Electric currents themselves create magnetic fields. Eventually scientists and inventors like Michael Faraday and Nikola Tesla would be able to manipulate magnets and electricity to form techniques and power systems that we use today. Later on, the atomic explanation of magnetism and electricity was established.
The reason why some materials, like a steel whiteboard, allow magnets to “stick” to them relates to their electrons. The atoms of these materials feature less pairs of electrons and more spare electrons than other materials. Pairs of electrons create no-fun atoms, as the spinning alternates in pairs and cancels each other’s out. Some metals are not really magnetic, like tin, lead or zinc, whereas other metals and alloys are more magnetic. Steel is comprised of a lot of iron, which is a magnetic metal with loose, spinning electrons. This is why factory-made magnets can stick to refrigerators, whiteboards, and other steel surfaces. These factory-made magnets alter the north and south poles all on one side, so that it can stick to steel.
Magnets range in size, shape, type, power, and use, from a small magnet on your whiteboard to the largest and most powerful man-made magnets in CERN. Without electromagnetism, life would likely not exist, the planet would not have an atmosphere, atoms would be structured differently, and matter as a whole would likely form another shape entirely. Our universe would be unrecognizable! Use the following resources to learn more about magnetism and its role in today’s technology:
- Magnets and Technology
- Q&A: What is a Magnet?
- Introduction to Magnetism and Induced Currents
- The Earth’s Magnetic Field
- Magnetic Field and Magnetic Forces
- Gravity Versus Magnetics
- Historical Beginnings of Theories of Electricity and Magnetism
- The Electromagnet