 Introduction

Radio waves are known to have the longest wavelengths1 and smallest frequencies2 in the electromagnetic system. Their wavelengths range from 30 cm to thousands of meters and their frequency can range from as low as 3 Hz to 1 GHz (equivalent to 1 x 10^9 Hz). To visualize the vast size of radio waves, radio waves can be seen to range from the size of a football field to being larger than our planet comparatively.

Discovery

Radio waves were first mathematically predicted by Scottish physicist James Clerk Maxwell. This mathematical theory is now termed as “Maxwell’s equations,” and it predicted that electric and magnetic fields could travel through space together as “electromagnetic waves.”

This idea was later proven to exist by German physicist Heinrich Rudolph Hertz in the late 1800s through a series of experiments. After reading Maxwell’s papers, Hertz experimentally tested Maxwell’s theory using a spark gap that was attached to an induction coil and then to a separate spark gap on a receiving antenna. Through this experiment Hertz found that radio waves exhibited the same wave properties of light (for example structure, polarization, diffraction, etc).

Uses

Telescopes

Since many astronomical objects in the universe emit radio waves, radio telescopes were developed to be able to create images from detecting the radio waves emitted by these bodies. Studying the radio waves being emitted by astronomical objects allows astronomers to be able to learn about the specific objects’ composition, density, structure, and motion.

Television

Very similar to the radio, radio waves can be used in television to receive and then broadcast signals onto the screen after being transformed to visual images.

Conclusion

Radio waves are a very important part of the electromagnetic spectrum that is utilized in everyday life often. Known for having a long wavelength and short frequency, radio waves are able to be implemented into uses such as telescopes, radios, and televisions to just name a few.

1 A wavelength is defined by the distance a wave takes to complete one cycle (NASA, 2022)

2 Frequency is the number of cycles a wave repeats in a second (NASA, 2022)

References