2.10 : Know Your Compass

Know Your Compass

A compass is a simple but essential tool for finding directions. It works by pointing toward Earth’s magnetic north. The needle inside the compass is magnetized and always aligns with Earth’s magnetic field. This makes a valuable compass for travelers, explorers, and scientists who need to find their way without using GPS.

Science and Engineering Practices (SEP - Engaging in Argument from Evidence)

Is a compass better than GPS for finding directions? You can explore this by learning how compasses have been used throughout history and comparing them to modern navigation tools.

Activity:

• To see magnetism in action, make your own compass using a needle, a magnet, and a small dish of water.
• Test an accurate compass in different places to see if buildings, power lines, or other objects affect its operation.
• Compare compasses and GPS to determine which is more reliable in different situations.

Think about these questions:

• How does a compass help people find their way without technology?
• What are the advantages and disadvantages of using a compass instead of GPS?
• Can things like metal objects or electricity affect how a compass works?

Crosscutting Concept (CCC - Scale, Proportion, and Quantity)

Earth’s magnetic field is vast, but even small changes can affect navigation. In some places, a compass doesn’t point exactly north due to magnetic declination, which is the difference between magnetic north and true north. Pilots, sailors, and hikers must adjust their readings to stay on course.

Different compasses are designed for different types of navigation:

• Hiking compasses help travelers navigate through forests and mountains.
• Marine compasses are used on ships to maintain direction across oceans.
• Aviation compasses assist pilots in-flight navigation.

This shows how scale and proportion play a significant role in real-world navigation.

Even though most people use GPS today, compasses remain essential, especially for outdoor adventures, flying airplanes, and sailing ships. You can understand its role in navigation by learning how a compass works and testing one yourself. Whether hiking, sailing, or just curious about Earth’s magnetism, compasses are a valuable tool for exploring the world.