Radios

Long before the internet, scientists found a way to send messages across the world. Energy waves that move within a certain range called the radio frequency spectrum can carry sound. They are called radio waves. Energy waves are best known for their use in communication technologies such as telephones, radios, satellites, navigation, and even cell phones. These devices receive radio waves and convert them to mechanical vibrations in the speaker to create sound waves.

In 1885, Heinrich Hertz proved that radio waves exist. This discovery quickly changed how people communicate. Because ships had no way to reach people on land, they were the perfect place to try early radio transmitters.