EMSpectrum - Microwaves and radio waves are used for...

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Electromagnetic Spectrum Maxwell’s theory predicts that electromagnetic waves travel at a speed of c = 300Mm/s and differ only in frequency and wavelength. The visible spectrum of light is only a tiny portion of the total electromagnetic spectrum . The figure to the right shows much more. Our eyes detect light over about one doubling or octave , and mix three basic reception ranges, red , green , and blue to form every color we can distinguish. Since violet light has twice the frequency of red light, it seems to go well with it counting every other wave pulse, just as middle C on a piano sounds very good with the next C above it. Many insects and birds can see into the ultraviolet region. Our skin will tan or burn from exposure to some kinds of it. Our skin can also sense heat in the infrared region, and there are reptiles that have special detectors for it.
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Unformatted text preview: Microwaves and radio waves are used for industrial and communication purposes, while increasingly high frequencies from x-rays through gamma rays can be very dangerous with more than minimal exposure. In theory, the EM spectrum continues much farther on both ends, but our knowledge of it is very limited. f λ Octaves 1ZHz 300fm __ __ 300EHz 1pm __ __ __ 30EHz 10pm __ __ __ __ __ 1EHz 300pm __ __ 300PHz 1nm __ __ __ 30PHz 10nm __ __ __ __ __ 1PHz 300nm __ 380-760nm __ 300THz 1 µ m __ __ __ 30THz 10 µ m __ __ __ __ __ 1THz 300 µ m __ __ 300GHz 1mm __ __ __ 30GHz 10mm __ __ __ __ __ 1GHz 300mm __ __ 300MHz 1m __ __ __ 30MHz 10m __ __ __ __ __ 1MHz 300m __ __ 300kHz 1km __ __ __ Gamma Rays X-rays Ultraviolet Visible Light Infrared Microwaves Radio Waves Long Waves Microwave Oven 2.45GHz FM Radio AM Radio Heat Vision Radar Dental X-rays UVA...
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This note was uploaded on 04/05/2012 for the course PHYS 131 taught by Professor Tibbets during the Spring '11 term at Cuyamaca College.

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