How does a compass?

A compass is an important means of orientation and is part of several modern navigation devices. It owes its effect to the presence of the earth's magnetic field and points to most places on earth the geographic north, the Arctic, to. Read more below about the history of a compass, the operation of a compass, using a compass and its accuracy.
Compass 
A compass is a device that is used to display the current direction relative to the north, to be determined. A compass always points north. This one can orient and determine the direction to go. It is already in the 12th century for the first time the concept of 'compass' spoken.

Earth's magnetic field 
The earth's magnetic field plays an important role in the operation of a compass. The Earth's magnetic field is the magnetic field around the earth is. Roughly speaking, the Earth's magnetic field to be described on the basis of a magnetic south pole is situated in the north and a north pole mach ethical which is located in the south. This description is called the geomagnetic dipole field called.
How does a compass? 
In the compass needle. This needle is magnetic, because the earth is also magnetic. A magnet has the property that opposites attract each other and the same poles repel. A north pole of a magnet emits just a north pole of another magnet off. A north pole of one magnet and the south pole of a magnet attract each other, however. Now imagine the Earth as a big bar magnet of the geographic North Pole to the geographic South Pole is running, then the south pole of the magnet at the North Pole and the North Pole to the South Pole of the magnet. Furthermore, given that the needle in your compass as end has a north pole. This means that the magnetic south pole and the north pole of the needle of your compass attract each other. Since the magnetic south pole is located at the North Pole, the magnetic needle of your compass always points north.
Use of a compass 
Since the advent of modern navigation systems is the use of the compass drastically reduced. Individuals make much less use of the old-fashioned, physical compass and increasingly have a compass built into their mobile phone or navigation system. In the shipping and air compasses are also no longer used to set the course, but they are still obliged to serve as a navigation aid in times of emergency.
Accuracy 
A compass is not on earth the same accuracy. Here in the Netherlands, the exemption currently about half a degree, making a compass almost always exactly the geographic north. In other parts on earth could a compass more than a degree or even tens of degrees differ. Close to the Arctic and Antarctic is a compass to not use.