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ELECTROMAGNETIC SPECTRUM. Objectives. The types of radiation Characteristics Wavelength Frequency Uses Hazards 3. Applications Understanding planetary images Understanding satellite photographs. Essential question.
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Objectives • The types of radiation • Characteristics • Wavelength • Frequency • Uses • Hazards 3. Applications • Understanding planetary images • Understanding satellite photographs
Essential question • What conditions on Earth would change if different wavelength of the EMS travelled at vastly different speeds? • What would we know about our universe if we did not understand the EMS? • How would life be different if humans could see all wavelengths?
Key question Compare and contrast the waves in the electromagnetic spectrum. * Construct a chart
Cornell Notes • Electromagnetic radiation is a form of energy that travels through space in waves. • Electromagnetic waves are transverse waves. • Properties of these waves depend on their wavelength. • Most electromagnetic radiation except visible light is blocked by Earth’s atmosphere.
Comparison of wavelength, frequency and energy Radio Microwaves Infrared Visible Ultra-violet X-rays Gamma rays Wavelength decreases • Frequency increases • Energy increases
Visible light is found in the middle of the Spectrum. Red ---- longest wavelength Violet ---- shortest wavelength
Radio Waves • Used for cell phones, TV, communication • In space radio waves are used to detect stars, galaxies, pulsars • Long wavelength, low frequency and low energy
Microwaves • Used on Earth to monitor melting of the polar ice caps due to global warming. • In space microwaves are part of cosmic background which gave clues as to the beginning of the universe. • Measure depth of seas/oceans
Infrared • Heat energy makes skin feel warm • Gives us clues as to the beginning of the universe. • In astronomy infrared radiation can penetrate dust and clouds enabling us to see newly forming stars. • Used to obtain temperature data of land, ocean surfaces and clouds.
Visible • EM waves that we can see • Used for viewing the sun, stars
Ultra Violet • Can cause sunburn/skin cancer in humans • In astronomy help to identify young and old stars. • Short wavelength, high frequency and high energy.
X-rays • Used for medical reasons • In astronomy x-rays help identify neutron stars and black holes. • Short wavelength, high frequency and high energy
Gamma rays • Used to kill cancer cells. • In astronomy help identify neutron stars and black holes. • Short wavelength, high frequency, high energy