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Discover the various types of electromagnetic waves, from low-energy radio waves to high-energy gamma rays, and their uses in communication, medicine, and more.
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Chapter 4 The Electromagnetic Spectrum Part 2
Radio waves • Low energy waves with long wavelengths and low frequencies. • Includes FM, AM, radar and TV waves • Used in many devices such as remote control items, cell phones, wireless devices, etc.
Microwaves • Shorter than radio waves. • First used in radar, now used in communication (wireless LAN networks), and consumer use (microwave ovens). • medical applications in cancer treatment (destroy tumors by heating them). • Most radio astronomy uses microwaves • “Active Denial System” – the “Pain Ray”
Infrared radiation is popularly known as "heat" Used in heat lamps, de-icing systems and thermomedic therapy. Higher energy than microwaves but lower than visible light Missile guidance systems, short range communication systems Can be detected with special devices such as night goggles Weather satellites Infrared Waves
Visible Light • The portion of the electromagnetic spectrum that human eyes can detect • ROY G BIV (red, orange, yellow, green, blue, indigo, violet) • Red is the lowest frequency and violet is the highest frequency
Visible Spectrum We perceive electromagnetic energy having wavelengths in the range 400-700 nm as visible light.
Ultraviolet • Higher energy than light waves • Can cause skin cancer and blindness in humans • Used in tanning beds and sterilizing equipment • UV watermarks • UV identification
X-Rays • Shorter higher energy waves than ultraviolet. • Used in medicine.
Gamma rays • Highest energy and most dangerous type of radiation. • Can cause cancer through damage to DNA. • Blocked from Earth’s surface by atmosphere. • Used in medicine and irradiation.
Homework • Chapter 4: Worksheet 2