Earth's Magnetic Field:
* The Earth acts like a giant magnet. It has a magnetic field that extends out into space.
* The magnetic field lines: These lines of force flow from the Earth's magnetic south pole to its magnetic north pole.
* Magnetic poles vs. geographic poles: Importantly, the magnetic poles and the geographic poles (where the Earth's axis of rotation intersects the surface) are not in exactly the same place.
How a Compass Works:
* A compass needle is a small magnet. It has a north-seeking pole and a south-seeking pole.
* Like poles repel, opposite poles attract. When a compass is free to rotate, its north-seeking pole aligns with the Earth's magnetic field lines, pointing towards the Earth's magnetic north pole.
Why North?
* The compass needle points towards the Earth's magnetic north pole, which is currently located near the geographic North Pole. However, the Earth's magnetic field is dynamic and changes over time.
In summary: A compass points north because the magnetic field lines of the Earth's magnetic field flow from the south pole to the north pole, and the compass needle aligns itself with these lines.
