Electromagnetic+Spectrum+&+Light

=Summary= The spectrum is a range of frequencies of electromagnetic radiation, some frequencies are visible, some need objects to be seen and some cannot be seen at all. With waves that range between California to Alaska and some even with a range of one millimeter. Every part of the electromagnetic spectrum has frequencies of electromagnetic radiation. Electromagnetic radiation can also be described as streaming photons, which travel at the speed of light, therefore all the electromagnetic radiation waves travel at the speed of light. Also all parts of the electromagnetic spectrum are electromagnetic waves therefore they do not need a medium to transport their energy.

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=EM frequency trends=
 * //**Region**// || //**Frequency (Hz)**// || //**Wavelength (m)**// || //**Energy (eV)**// || //**Size Scale**// ||
 * Radio waves || < 10 9 || > 0.3 || < 7x 10 -7 || Mountains, building ||
 * Microwaves || 10 9 - 3x10 11 || 0.001 - 0.3 || 7x10 -7 - 2x10 -4 || People ||
 * Infrared || 3x10 11 - 3.9x10 14 || 7.6x10 -7 - 0.001 || 2x10 -4 - 0.3 || A Bee ||
 * Visible || 3.9x10 14 - 7.9x10 14 || 3.8x10 -7 - 7.6x10 -7 || 0.3 - 0.5 || Bacteria ||
 * Ultraviolet || 7.9x10 14 - 3.4x10 16 || 8x10 -9 - 3.8x10 -7 || 0.5 - 20 || Viruses ||
 * X-rays || 3.4x10 16 - 5x10 19 || 6x10- 12 - 8x10 -9 || 20 - 3x10 4 || Atoms ||
 * Gamma Rays || > 5x10 19 || < 6x10 -12 || > 3x10 4 || Nuclei ||

= = =Speed of light= The speed of light is 299,792,458 meters per second (m/s) or 186,282 miles per second. The sun is 150 million kilometers from earth. if light from the sun travels at 300,000 kilometers per second, therefore it takes around 8 minutes from light produced from the sun to travel to earth. The speed of light only travels 300,000 kilometers per second because when speaking of the speed of light, we mean the speed of light in a vacuum, therefore light travels much slower when in a medium. Albert Einstein's theory is correct in which he said nothing can go faster then the speed of light with mass or a medium.

=All parts of the Electromagnetic Spectrummedia type="youtube" key="al7sFP4C2TY" width="382" height="315" align="right"=

Radio
The first mathematical theory of the existence of radio waves was discovered in 1965, and the first radio transmission was made in 1894. This radio transmission created a radio wave which past many planets and stars around the universe. In 1903 the wave past sirious, in 1919 it past vega and in 1971 it past regulus. Radio waves are usually crated by antennas which use the effect of **resonance.** These antennas are used to transmit data and these may be phones, wireless networking and television.

The radio waves have very long wavelength therefore they may travel far distance but with low frequency and low energy and possess's the longest wavelength on the EM spectrum.

Microwaves
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[[image:http://www.darvill.clara.net/emag/images/IRremotePhoneCam.jpg align="right"]]
Infrared lies between the visible and microwaves in the electromagnetic spectrum. This means that infrared waves have shorter wavelength, higher frequency and higher energy then microwaves and longer wavelength, lower frequency and lower energy then visible waves. Infrared waves are used also in the modern era for many purposes such as remote controls for televisions. Infrared is also useful for detecting temperatures on cameras and satellites. Using Infrared as technology is useful even for military purpose such as night vision and thermal scopes.

Visible light
Our eyes are only able to see little part of the electromagnetic spectrum. This is called visible light. Seeing the sun has sent so much light, humans were able to evolve to sense the world around us which is a theory why humans can only see this part of the electromagnetic spectrum. Visible light can be created from light bulbs, the sun, stars and many other objects. The speed of light may travel within a vacuum of 299,792,458 m/s (meters per second).

Ultravioletmedia type="youtube" key="vA9Ik1BDpJw" width="381" height="315" align="right"
Ultraviolet (UV) radiation is invisible to the human eye, although we know of it commonly because of sunburn. Humans are able to make ultraviolet rays with special lamps or special lightings. In some nightclubs there are lamps that produce ultraviolet waves which make peoples clothes and drinks glow in the dark. This happens because ingredients in washing powder glow when UV light strikes them.



X-rays
media type="youtube" key="0oy0fYeV764" width="382" height="315" align="right" X-rays are very high in frequency and energy, therefore they have enough energy to pass through objects. X-rays have wavelengths that range to 0.01 to 10 nanometers. In our modern society X-rays contribute to health issues, such as detecting which bones are broken. X-rays with higher frequencies and energy are also used for radio therapy for reducing size of cancer tumors.

**Gamma Rays** Gamma rays on the electromagnetic spectrum have the highest energy, highest frequency and shortest wavelength known to man on the electromagnetic spectrum. Gamma rays are extremely dangerous and are used for radio therapy . Gamma rays are created by atomic substances (see diagram with the atomic atom creating a gamma ray). A gamma rays frequency is 10 to the power of 19 Hz (10,000,000,000,000,000,000) therefore it creates 10 to the power of 19 waves per second. The amount of energy these waves possess enough to destroy the atmosphere. =media type="custom" key="10183261"=