History of radio waves <ul><li>Radio waves belong to a group known as the electromagnetic spectrum, they are longer than infra-red. </li></ul><ul><li>Radio owes it's development to both the telegraph and the telephone. It was originally know as 'wireless telegraphy.' </li></ul><ul><li>In 1915 speech was able to be transmitted from New York to San Francisco, making way for AM radio. </li></ul><ul><li>The television set became commercially available in the 1920s, another development for radio waves, and making them more commonplace in everyday life. </li></ul>
The Importance of Radio Waves <ul><li>An important, but often overlooked fact is that they silently transmit across the world. </li></ul><ul><li>An important component of most technological advances in the late 20 th century </li></ul><ul><li>Radio waves serve as the basis for for nearly all non-written types of communications, including but not limited to a phone call, radio and television. </li></ul><ul><li>Radio waves have the capabilities of carrying things like pictures, audio, data and conversations. </li></ul><ul><li>Radio waves can be found in toys as simple as remote controlled cars and can be found in the obvious things like AM and FM radios. </li></ul>
Frequencies. <ul><li>Radio frequencies start from as low as 3Hz (known as extremely low frequency) to 300GHz (known as extremely high frequency) </li></ul><ul><li>Different types of radio waves have different frequencies, for example television has a frequency range of 54 – 1600 MHz and a wavelength of 0.187m – 5.55m </li></ul><ul><li>Bluetooth as another example has a frequency range of 2400 – 2483.5 MHz and a wavelength of 10cm. </li></ul>
Wi-Fi (wireless networks) <ul><li>One of the newer uses for radio waves, but quickly became a prominent one. Wi-Fi is used in most homes and a lot of good coffee shops/restaurants/ pubs etc. </li></ul><ul><li>Because of radio waves managing to cover long distances and the internet becoming the most useful resource commercially available Wi-Fi is an important way to communicate/work on the go. Wi-Fi's frequency varies between 2.4 GHz and 5GHz and wavelength varies depending on the power of the device. </li></ul><ul><li>Some business offer free wireless, such as Wetherspoons, National Express, McDonalds, but others see it as a money making opportunity such as Starbucks and BT. </li></ul>
What else is it used for? <ul><li>Radio waves doesn't just have communication and entertainment uses, it expand into safety, medical and detection purposes, to name a few. </li></ul><ul><li>For example, police scanners and MRI machines. </li></ul><ul><li>While some radio signals can be turned off or changed, such as AM/FM radio or what you receive via your TV set, there are still thousands of radio waves darting past you, this could be in the form of police scanners. </li></ul><ul><li>MRI (Magnetic Resonance Imaging) produce internal images it is used in medicine to find problems such as cancer, broken bones and more. </li></ul>
Radio waves in Astronomy <ul><li>Humans possess this lust for knowledge which is the main catalyst behind any major development in history. One of the more perplexing things is space and the development of radio waves have helped Astronomy as well. </li></ul><ul><li>On the electromagnetic spectrum you'll notice visible light is mention, this is everything that we can see, if you look up to the sky, you can see the stars and if you're really lucky a planet or two, however, the used of radio waves help us to look further. </li></ul><ul><li>Using radio astronomy scientists can search for celestial objects that give off radio waves that would otherwise be invisible. </li></ul>
Other bits of information about Radio waves <ul><li>Natural radio waves are created by things like lightning and astronomical objects, this means that most radio waves are man-made and have been created for the purposes in which they are used. </li></ul><ul><li>Radio waves, like everything else on the electromagnetic spectrum travels at the speed of light, this is the reason we cannot see the radio waves, they are simply travelling too fast to comprehend with the naked eye. </li></ul><ul><li>Long waves can travel the earth quite consistantly, but shorter waves may reflect of the earth’s ionosphere and travel the world easily. </li></ul>
Conclusion <ul><li>Radio waves are commonplace everyday, thousands of radio waves are flying past you and I at this very moment. </li></ul><ul><li>Radio waves are used for all purposes, including entertainment, communication, medical, safety, discovery and so much. </li></ul><ul><li>Radio waves can have varying wavelengths and frequencies. Radio waves are at the end of the electro magnetic spectrum, after microwaves. </li></ul><ul><li>Radio waves travel too fast for people to see. Not only are they invisible but they are silent too. </li></ul>
Bibliography <ul><li>Curiosity.com, 2011 Importance of Radio Waves [online] Available at http://curiosity.discovery.com/question/what-importance-of-radio-waves [accessed 29/01/12] </li></ul><ul><li>About.com, 2012 The Invention of Radio [online] Available at: http://inventors.about.com/od/rstartinventions/a/radio.htm </li></ul><ul><li>Wikipedia.com, 2012 Radio Frequency [online] Available at: http://en.wikipedia.org/wiki/Radio_frequency [accessed 29/01/12] </li></ul><ul><li>Radio Police Scanners, 2008 Scanners Scanners Police Scanners [online] http://www.radiopolicescanners.com/ [accessed 29/01/12] </li></ul><ul><li>BBC Learning Zone, 2012 Radio Waves and MRI Scans [video online]http://www.bbc.co.uk/learningzone/clips/radio-waves-and-mri-scans-the-electromagnetic-spectrum/1457.html [accessed 29/01/12] </li></ul><ul><li>NRAO.edu, 2012 Radio Astronomy [online] http://www.nrao.edu/index.php/learn/radioastronomy/ </li></ul><ul><li>Wikipedia.org, 2012 Radio Waves [online]http://en.wikipedia.org/wiki/Radio_waves [accessed 29/01/12] </li></ul>
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