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Confusion About the North Magnetic Pole
by Ron Kurtus (updated 30 May 2023)
There is often confusion concerning the magnetic polarity of the Earth's North Magnetic Pole compared with the north pole of a magnet or compass. This has to do with the historical naming of both entities.
Since opposite magnetic poles attract, and the fact that the N pole of a compass points north, the magnetic field from the North Magnetic Pole must really be a south magnetic field.
A good way to avoid confusion is to called the poles of a magnet or a compass as the north-seeking pole and south-seeking pole.
Questions you may have include:
- How were the compass poles named?
- How were Earth's magnet poles named?
- What is the prevailing naming convention?
This lesson will answer those questions. Useful tool: Units Conversion
Naming compass poles
The compass was invented in China the early eleventh century. It consisted of a floating magnetic needle or a suspended magnet that would rotate and point in the north and south directions. It was later used in navigation.
For a long time, it was thought that the compass pointed toward the North Star. That end or pole of the compass was called the north pole of the magnet. Often the north pole of the magnet was colored red and marked with "N".
This naming convention for magnets has thus been in effect for hundreds of years.
Discovering Earth's Magnetic Poles
It wasn't until the 1600s when astronomer William Gilbert discovered that the Earth had a magnetic field coming from an area near the North and South geographical poles. It was assumed that the Earth was like a huge magnet and those areas were named the Earth's North and South Magnetic Poles.
They have had those designations since then.
Naming convention
However, since opposite poles of a magnet attract each other, and the fact that the N pole of a magnet or compass points toward the Earth's North Magnetic Pole, one of them has been incorrectly named. The magnetic fields or poles must be opposite in order to attract each other.
Earth's magnetic fields
Since the north pole of a compass is attracted to the North Magnetic Pole, then the polarity of the North Magnetic Pole must really be south! This can be seen in the illustration below:
Earth's magnetic field designation
Image from Physics.org - Courtesy of Wikimedia Commons
This was confusing, but scientists felt that it was easier to say the Earth's internal magnet had its south pole facing the North Magnetic Pole than to try to change the way the public called their magnets.
Note: This situation is similar to that in electricity, where by convention electrical current goes from positive (+) to negative (−), but electrons move in the opposite direction in a wire. Once things were designated and in common use, they could not be readily changed.
Suggested designation
A suggested solution to this problem is to use the designation of the poles on a magnet or compass as north-seeking pole and south-seeking pole.
Summary
The confusion about the names of the Earth's Magnetic Poles and the poles of a compass or bar magnet come from the historical naming of the poles.
Since the north (N) pole of a compass is attracted to the Earth's North Magnetic Pole, that pole must really be the south pole of the magnetic material within the Earth.
To avoid confusion, the best route is to be careful with your terminology. It is best to call the ends of a compass or bar magnet the north-seeking pole and south-seeking pole.
Try to use logical conventions
Resources and references
The following are resources on this subject.
Websites
North Magnetic Pole - Wikipedia
Earth's Magnetic Poles - Windows to the Universe
History of geomagnetism - Wikipedia
What Are Magnetic Poles? - Study.com
William Gilbert - astronomer - Wikipedia
Why the North pole is actually a South seeking pole - Physics.org
Books
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Students and researchers
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www.school-for-champions.com/science/
magnetic_pole_confusion.htm
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Confusion About the North Magnetic Pole