The Compass
How the compass works, how to trust your phone compass, and how to find your way when you have neither.
The needleHow a compass works
The Earth is a giant, weak magnet. A magnetised needle that can turn freely lines up with its field and points to magnetic north. The first magnetic pointers appeared in China about two thousand years ago; by around the year 1100 Chinese sailors were steering by them.
Magnetic north is not true north. The difference is called declination. In Greece today it is only a few degrees east, small enough for walking; for long distances and maps, correct for it.
In your pocketYour phone compass, done right
- Calibrate it. If it seems wrong, move the phone slowly in a figure-eight a few times.
- Keep it away from metal and magnets: cars, rails, magnetic phone cases and speakers all pull the reading.
- Hold it flat and away from your body, and wait a second for it to settle.
No compass at allFind your way by the sky (northern half of the world)
- The Sun rises in the east and sets in the west. Around midday it stands due south.
- The North Star. Find the Big Dipper. Follow the two stars at the end of its "cup" upward, about five times their distance: the steady star you reach is Polaris, almost exactly north.
- The watch method. With a watch with hands, point the hour hand at the Sun. Halfway between the hour hand and the 12 is south. In summer time, use the 1 instead of the 12.
These methods are good enough to keep a direction, not to aim for a small point. In real danger, stay where you are and call 112.
Go deeperSources
Everything on this page was written for you here. These are the places we drew from, if you want to walk further on your own: