The behaviour of a compass shows that the Earth has a magnetic field. The Earth’s core, which is made from iron and nickel, produces this magnetic field.

Detecting magnetic fields A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet on a pivot so that it can rotate.

Biologists find captive sharks can sense magnetic fields. Finding adds evidence sharks use an internal compass to navigate across oceans. CBC News · Posted: Dec 15, 2004 1:35 PM EST | Last ...

The claim: A compass wouldn't work if Earth is spherical Earth is surrounded by a magnetic field generated by electric currents from within the planet. Compasses take advantage of this field to ...

The result that magnetic-field detection might have evolved separately for the map and compass senses bolsters growing evidence for dual magnetoreception systems in other vertebrates 1, 3.

The compass consists of a domino-sized chip filled with rubidium-87 atoms heated to exactly 113 degrees. These magnetically sensitive atoms orient themselves in certain ways when in the presence ...