When we first realized that the Earth had two poles and that each of them had different magnetic charges, it enabled us to invent the compass. First invented in China, it was found that a resting strip of magnetic iron atop a pin would spin until it matched the magnetic field of the Earth, thus enabling someone to navigate with great accuracy.
When we first realized that the Earth had two poles and that each of them had different magnetic charges, it enabled us to invent the compass. First invented in China, it was found that a resting strip of magnetic iron atop a pin would spin until it matched the magnetic field of the Earth, thus enabling someone to navigate with great accuracy.