By Noah Evans
What is an Electromagnetic Wave?
An electromagnetic wave is formed by a vibration in electric and magnetic fields. The wave will carry on travelling in it's original direction at the speed of light until contact with another form of matter. The difference between an electromatic wave and a mechanical wave is the medium. Electromagnetic waves travel through a vacuum while mechanical waves need a physical medium to pass through. Another difference is speed. An electromagnetic wave is faster than any known mechanical wave.
There are Many Kinds of Electromatic Waves...
Visible light is in the exact middle of the spectrum. It's waves carry an even amount of energy, an even frequency, and a balanced wavelength. Visible light is also the only electromagnetic wave form we can see. It is divided into seven colors: Red, orange, yellow, green, blue, indigo, and violet. Many things emit visible light. Light bulbs and stars are examples of such. (Pink Floyd proved their knowledge of visible light with their famous album cover, Dark Side of the Moon!)
Ultra-violet rays are one step above visible light. They have more energy, a higher frequency, and shorter wavelength. Ultra-violet rays can be very harmful to skin, as they are emitted by the sun and can cause sunburn. Ultra-violet rays are also used in blacklights. They are called blacklights because we can't see the ultra-violet light that is emitted from it.
X-rays are the second on the spectrum for most energy. They have more energy, longer wavelength, and higher frequency than ultra-violet rays, but less than gamma rays. Of course, the most common use of the X-ray is in the X-rays that doctors use to see a patient's bones, but did you know they are also used to measure atoms? Scientists can measure the distances between atoms with a process called X-ray diffraction.
At the highest end of the spectrum, we have gamma rays. Gamma rays have the highest amounts of energy, the shortest wavelength, and the highest frequency than any other electromagnetic wave. Gamma rays are emitted in very short and quick bursts. They can come from strikes of lightning and nuclear explosions.
Still confused? Check out this video!
The Electromagnetic Spectrum