Q:

How do I describe how a compass needle aligns itself?

A:

Quick Answer

A compass needle is made of magnetized material and points toward Earth's north magnetic pole no matter which direction the compass faces. Therefore, it is an excellent low-tech tool with which to find direction. Earth has a powerful magnetic field that emanates from the axis of rotation. Magnets are created from materials whose electrons all point the same direction and are attracted to an opposite charge.

Continue Reading
How do I describe how a compass needle aligns itself?
Credit: fstop123 E+ Getty Images

Full Answer

The Earth's magnetic field is thought to be generated mostly by the rotation of the liquid iron outer core around the solid iron inner core that produces the so-called "dynamo effect." Any magnetic material that rotates fast enough for its size begins producing an electric current. Because electricity and magnetism are linked, the current then produces a rotating field. Also, friction pulls electrons free and enables them to flow in a rotating current.

The magnetic field surrounding the Earth is tilted approximately 11 degrees from the rotational axis, so a compass cannot always reliably point true north. In addition, the field reverses polarity periodically. One popular theory stated that the magnetic poles were due to shift in 2012, causing mass havoc with electronics, communications and other technological devices. This phenomenon, however, did not occur.

Learn more about Magnetism

Related Questions

  • Q:

    How do magnetic compasses work?

    A:

    A compass works by aligning its magnetic needle with the Earth's magnetic field, which is created by the iron core deep inside the planet. A compass is exactly accurate since the Earth's magnetic north differs slightly from Earth's true north.

    Full Answer >
    Filed Under:
  • Q:

    What is a compass used for?

    A:

    A compass is a navigational tool that marks direction according to the earth's rotation cycle or its magnetic field. Compasses can be used for plotting and tracking journeys of predetermined direction on land or at sea.

    Full Answer >
    Filed Under:
  • Q:

    How is a compass used?

    A:

    Store-bought compasses have a lightweight and magnetized pointer fixed on a low-friction pivot; a small plastic cylinder filled with liquid seals the pointer. Settle the needle and rotate the compass card (the layer of plastic encasing the cylinder) until the needle lines up with the north/south axis label.

    Full Answer >
    Filed Under:
  • Q:

    Who invented the magnetic compass?

    A:

    The magnetic compass was invented by the Chinese around the 4th century B.C., and was originally used as a figurative aid to help manage their daily lives. It was introduced to Europe in the 14th century, where it was improved upon and used as a navigational aid.

    Full Answer >
    Filed Under:

Explore