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Compass

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A compass is a tool used for navigation and finding directions. It helps people know which way is north, south, east, or west.

walkers compass arp
walkers compass arp

Most compasses use a magnetized needle to show the way. This needle is able to pivot or turn very easily. It points toward magnetic north to help travelers find their path. Some modern tools use other ways like GPS or gyroscopes to find location. Knowing your direction is a very important skill for many people.

Compasses orienteering
Compasses orienteering

How does a compass work so well? The Earth has a magnetic field that surrounds the whole planet. This field exerts a torque, which is a turning force, on the needle. This force pulls the north end of the needle toward the Earth's North magnetic pole. It pulls the other end toward the South magnetic pole.

Cammenga-lensatic-compass-model-27
Cammenga-lensatic-compass-model-27

To make it work, the needle sits on a low-friction pivot point. In better compasses, this is called a jewel bearing. When you hold the compass level, the needle settles into place after a few seconds. The liquid inside many modern compasses helps stop the needle from wobbling too much.

People have used magnets to find direction for a very long time. The Greek philosopher Thales of Miletus wrote about lodestone in the 6th century BC. Lodestone is a natural magnet made of iron ore.

Model Si Nan of Han Dynasty
Model Si Nan of Han Dynasty

In China, the magnetic compass was first used for divination during the Han dynasty. This was as early as 206 BC. Later, during the Song dynasty in the 11th century, Chinese people used it for navigation. The first records of compass use in Europe and the Islamic world appeared around 1190. These early discoveries changed how humans traveled across the world.

There are many specific facts about how we use compasses today. Directions are often shown in degrees to show an angle. North is 0 degrees, east is 90 degrees, south is 180 degrees, and west is 270 degrees.

Measuring azimuth with a compass
Measuring azimuth with a compass

Maps often show magnetic declination, which is the angle between true north and magnetic north. This angle changes depending on where you are on Earth. Some compasses even have special glowing parts to help you see at night. They might use phosphorescent paint or even tritium, which is a radioactive isotope of hydrogen. Tritritium provides light without needing to be recharged by the sun.

Compasses are linked to many things you might see in your daily life. You might see a compass used by a hiker in the woods.

Brunton
Brunton

Geologists use special versions, like the Brunton compass, to study the Earth. Even the military uses them to help soldiers find their way. Some compasses are filled with liquids like mineral oil or alcohol. These liquids help the needle stay steady even if the compass moves. Whether on a boat or a mountain, the compass remains a vital tool for finding the way home.

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🖼️ Images & Media (14)
File:2016 Busola.JPG
2016 Busola.JPG
File:Model Si Nan of Han Dynasty.jpg
Model Si Nan of Han Dynasty.jpg
File:walkers compass arp.jpg
walkers compass arp.jpg
File:Cammenga-lensatic-compass-model-27.jpg
Cammenga-lensatic-compass-model-27.jpg
File:CompassWick.jpg
CompassWick.jpg
File:מצפן.jpg
מצפן.jpg
File:Northerly and southerly turning errors.png
Northerly and southerly turning errors.png
File:Compasses orienteering.jpg
Compasses orienteering.jpg
File:Brunton.JPG
Brunton.JPG
File:Boussole fantassin russe.jpg
Boussole fantassin russe.jpg
File:MuseeMarine-compas-p1000468.jpg
MuseeMarine-compas-p1000468.jpg
File:CompassUseMapMarked.jpg
CompassUseMapMarked.jpg

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