# Electromagnetic Waves

## What kind of disturbance creates an EM wave?

In the electromagnetic spectrum, disturbances are generally caused by light. As you might already know, color is created when light, or lack thereof, bounces off of a medium and returns to the eye. Depending upon the amount of light that is reflected back to the eye, a different color will be seen. Since the electromagnetic spectrum is essentially the rainbow, the amount of light disturbance causes a different color to be seen. The speed of light is found by multiplying the frequency and the wavelength together.

## What is the Difference Between Electromagnetic Waves and Mechanical Waves?

While mechanical waves must have a medium to be able to function, electromagnetic waves do not. They can travel through what is called a vacuum. A vacuum is a place that lacks matter, therefore no sound can be produced inside of a vacuum. The electromagnetic wave has a much larger range of frequencies, whereas the mechanical wave does not have as large of a frequency range.

## What are the different ranges on the electromagnetic spectrum?

When using the electromagnetic spectrum, it is important to know that this spectrum is capable of using an enormous range of frequencies, much larger than the range of frequencies that a mechanical wave can reach. The range of the spectrum is broken into smaller components so it is easier to dissect. The longer wavelength and lower frequencies are located on the far left of the spectrum, and vice versa.

## Different Types of Waves on the Electromagnetic Spectrum and their uses

While your radio can capture radio waves to emit a series of frequencies and make music, stars in space also emit radio waves. Without radio waves, we wouldn't be able to watch TV. I'm sure you know microwaves do. They pop your popcorn and power your cellular phones! However, they are also used in the practice of astronomy to study nearby galaxies. Infrared waves are what is used in night vision goggles, which helps to pick up the infrared light on our skin. They are also used to power remote controls. Visible light is basically any kind of light that can be seen by the naked eye. Whether it's watching the stars or watching a sports team, you need visible light to make it happen. When you are on the beach, trying to tan, but you actually just burn, you may have taken in too many ultraviolet rays. Not only do they give you a tan, but they protect from the crime of forgery, because ultraviolet lights are used to detect fake money. Anything in space that produces masses of heat also produces ultraviolet rays. If you fall and hurt yourself, your doctor might give you an x-ray. Not only are they used to see through your bone, they are also used to produce photos inside the human body. Hot gasses in the sky also emit x-rays. Doctors use gamma rays to see inside of the human body, as well as used to kill cancer cells. The biggest creator of gamma rays is the universe itself.