After working on a painting as a kid, many parents would showcase the art by putting it on the fridge. Surprisingly, they never used any glue or tape, so how did the paper stick to the fridge? Magnets are tiny objects that can be used in a multitude of ways, including to hold papers on fridges, whiteboards, and more. They are rocks or metals that create an invisible field that attracts other magnets and certain metals. They have two ends called poles; one pole is called a north pole/north-seeking pole, while the other is called a south pole/south-seeking pole. The north pole of one magnet is attracted to the south pole of a second magnet while the north pole of one magnet repels the other magnet’s north pole. To remember this, think of “unlike poles attract, while like poles repel.” The magnet’s invisible field or area of magnetism around it is called a magnetic field. Most refrigerators have sheet steel doors and the magnetic field passes from the north poles of the sheet magnet to the south poles of the magnet sticking to the refrigerator door. Therefore, if you place paper between the magnets, the fields will still pass through it and be attracted to each other, holding the paper between the magnet and the fridge.
There are a lot more interesting facts about magnets! For example, if you cut a bar magnet in half, you will get two smaller magnets, each with its own north and south pole. If you rub a magnet a few times over an unmagnetized piece of magnetic material, you can convert it into a magnet through a process called magnetization. Magnets are found everywhere, including fans, washing machines, cars, and even compasses. In fact, the Earth itself has a magnetic field! The magnetic field of Earth is caused by currents of electricity that flow into the molten core. The core of the Earth has a powerful magnetic field that passes through the crust and enters space. Essentially the inner core region is surrounded by a molten outer core, and both contribute to Earth’s magnetic field. By the time the field has reached the surface of the Earth, it’s pretty weak. However, it is still strong enough to point the needles in compasses towards one of the poles: north or south.