Light waves are all around you.
In this lesson, you will learn about different kinds of light waves, how they work and how they are used every day. Explore this lesson to discover some surprising facts about light waves.
What Are Light Waves?
Did you know that light waves are all around you, even when it’s dark? You use light waves all the time, like when you play video games with wireless controllers and change the channel on your television using a remote control. How do light waves help you do these things? Well, light waves carry messages from one device to another, so they tell your game console or television what button you’re pushing.
So what are they? Light waves are forms of moving energy made of tiny microscopic particles called photons. Scientists usually refer to light waves as electromagnetic waves, because they make up what is known as the electromagnetic spectrum. (The term ‘electromagnetic’ means the waves are both electric and magnetic.)
Types of Light Waves
The electromagnetic spectrum is made up of seven types of waves, and where they sit on the spectrum depends on the size of the wave and how fast the wave vibrates, which is referred to as its frequency:• Radio waves have the longest waves. They’re used to send data, like from a broadcasting station to your radio or from cell towers to your cell phone.
; Microwaves are the second longest. We use these to create heat (that’s why we call the appliance we use to zap food a ‘microwave’) as well as to send information.• Infrared waves come in two different types: near and far. Near infrared waves send data (they’re the waves that make your game controller and remote control work), while far infrared waves create heat. In fact, your own body gives off far infrared waves.; Visible light is just what it sounds like–the light waves you can see with your eyes.; Ultraviolet waves get their name from the fact that they’re just beyond violet–they’re just past the last color our eyes can see on the color spectrum.
These come from the sun and help plants grow and humans produce vitamin D. They can also cause a lot of damage to your skin, which is why we wear sunscreen!; X-rays are very important to the medical field. These light waves can pass through human tissue, among other substances, allowing doctors to get an inside peek at your body.
; Gamma rays are the shortest waves of all. Because of their high frequency, they hold a lot of energy. That energy can be used to kill cancer cells, create atomic bombs and even preserve foods.Most of these waves can’t be seen by the human eye. In fact, visible light waves are the only kind you can see.
Let’s explore visible light in more detail.
How Do Visible Light Waves Work?
Visible light contains all the colors on the color spectrum, and the visible light waves work by reflecting or absorbing light to produce different colors. Each color has a different frequency–violet has very short, quickly vibrating waves (high frequency), while red has long, slowly vibrating waves (low frequency).
This determines how the color looks. Certain objects absorb some waves and reflect others depending on this frequency.
For example, when you see a red apple, the low-frequency red wavelengths are being reflected back to your eyes, while the other wavelengths are being absorbed by the apple. Visible light also explain why some objects can be black–all of the waves are absorbed and there are none reflected back.
Light waves, also called electromagnetic waves, are forms of moving energy made of tiny microscopic particles called photons. They make up the electromagnetic spectrum, which consists of radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays and gamma rays.