What tool uses a magnetic needle that points north?

What tool uses a magnetic needle that points north? A compass. Its magnetized needle rotates freely until it aligns with Earth’s magnetic field, giving the direction known as magnetic north.

The compass works because Earth behaves broadly like a giant magnet. The needle’s north-seeking end is attracted toward the planet’s magnetic north region, allowing travelers to determine direction without landmarks, the Sun, or stars. Most modern compasses also include a compass rose, degree markings, and a liquid-filled capsule that slows needle movement.

The magnetic compass has deep roots in China. Magnetic devices were used there for divination as early as the Han dynasty, around 206 BC, and were adapted for navigation during the Song dynasty in the 11th century. Knowledge of the compass reached Western Europe and the Islamic world by about 1190.

A common mix-up is saying that a compass points exactly to the geographic North Pole. It actually points toward magnetic north, which differs from true north by an angle called magnetic declination. That angle varies by location and changes gradually over time, so navigators and map users may need to account for it.