十万个为什么·科学启蒙30篇（1）
5 / 30
正在校验访问权限...
How Do Magnets Work?
磁铁是如何工作的？
-
Magnets create invisible fields of force that attract certain metals like iron, nickel, and cobalt.
-
Every magnet has two poles: north and south—and opposite poles pull toward each other while like poles push apart.
-
These magnetic forces come from the motion of electrons spinning and orbiting inside atoms of magnetic materials.
-
In unmagnetized iron, these tiny atomic magnets point in random directions, canceling each other out.
-
When exposed to a strong magnetic field, many of those atomic magnets line up and reinforce one another.
-
Earth itself acts like a giant magnet, with its magnetic field stretching far into space and protecting us from solar wind.
-
Compasses work because their magnetized needles align with Earth’s magnetic field lines, pointing toward magnetic north.
-
Heating or hammering a magnet can scramble its aligned atoms and weaken or destroy its magnetism.
-
Some animals, including pigeons and sea turtles, have tiny magnetic crystals in their bodies to help them navigate long distances.
-
Unlike electric charges, magnetic poles always come in pairs—you cannot isolate a single north or south pole.