The Types of Electromagnetic Waves

How do electromagnetic waves differ from each other?

EM waves that have different wavelengths can travel at the same speed, but their frequencies must also be different.




Radio waves and Microwaves

• Radio Waves

These waves cover a wide section of waves in the electromagnetic waves (EM) spectrum. Radio waves at most times have the longest wavelengths and the lowest frequencies of all types of EM waves. Any wavelength of an EM wave that is longer than 30 cm is considered a radio wave. 

Radio waves are used foe broadcasting radio signals. Radio stations compute sound information into radio waves by differing the waves' amplitude or their frequencies.Changing amplitude or frequencies is called modulation.

There are AM and FM radio stations. AM stands for "amplitude modulation" and FM is "frequency modulation".

Television signals are also carried by radio waves.

• Microwaves

Microwaves have shorter wavelengths and higher frequencies than radio waves do. You know when a wave is a microwave because their wavelength are between 1 mm and 30 cm. Microwaves are used to send information over long distances.
Microwaves are also used in radar. Radar (radio detection and ranging) is used to detect and see the speed and location of objects.




Infrared Waves

• Infrared Waves

Infrared waves have shorter wavelengths and higher frequencies than microwaves. The wave lengths of these waves differ between 700 nanometers (nm; is equal to 0.000000001 m) and 1 mm.
The sun is one source of infrared waves. Our skin absorbs these waves when they strike our body (from the sun). The energy from these waves causes particles in our skin to vibrate more, which cause our temperature to rise.
The amount of infrared waves an object repels and gives off depends on the object's temperature. Warmer objects give off more infrared waves. While cooler objects give off less.
Infrared waves are not visible to us. But some devises detect these waves.



Visible Light and Ultraviolet Light

• Visible Light

Visible light is the very narrow range of wavelengths and frequencies in the electromagnetic spectrum that us, humans, can see. Visible light waves have longer wavelengths and higher frequencies than infrared waves do. There wavelengths of these waves are between 400 nm and 700 nm.
Energy from the sun that reaches earth can be visible light. This visible light from the sun is white light. White light is visible light of all wavelengths added together.

• Ultraviolet Light

Ultraviolet light (UV light) is another type of electromagnetic wave produced by the sun. These waves have shorter wavelengths and higher frequencies than visible light does. The wavelengths of ultraviolet light waves differ between 60 nm and 400 nm. This light affects our bodies in both good and bad ways.
Some bad effects include sunburns. These types of waves can cause skin cancer, wrinkles, and damage to the eyes.
Some good effects include the killing of bacteria on food and surgical tools. Skin cells produce vitamin D when the skin is exposed to this light.


X rays and Gamma Rays

• X rays

X rays have wavelengths between 0.001 nm and 60 nm. They are able to pass through many materials. Though X rays are helpful, to much exposure to these waves can damage or even kill living cells.

• Gamma Rays

Gamma rays are electromagnetic waves that have wavelengths shorter than 0.1 nm. They are able to make a hole in most materials very easily. These rays are also used to kill harmful bacteria in foods, like meat and fresh fruits. They do not harm the food or stay in it.

Ryann Cornelius