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Total Internal Reflection. Refraction Review. Refraction means bending. How does light go through glass anyway? Does NOT go through! Absorbed & Re-emitted countless times. Glass Molecules. Photon of light. Gulp!. Gulp!. Gulp!. Gulp!. BURP!. BURP!. BURP!. BURP!.
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Refraction Review • Refraction means bending. • How does light go through glass anyway? • Does NOT go through! • Absorbed & Re-emitted countless times.
Glass Molecules Photon of light Gulp! Gulp! Gulp! Gulp! BURP! BURP! BURP! BURP!
Total Internal Reflection: Shine a light upwards out of water: • Some light will leave the water, • Some light will reflect back downwards at an equal angle.
Total Internal Reflection • At a certain angle... • Light doesn’t go through the surface of the water anymore! • Demo...
Occurs when: ni > nt andΘi > Θc
ni > nt : Θi > Θc : “Occurs when:ni > nt andΘi > Θc”What does this mean?
Finding the critical angle: • Sound familiar: • ni sinΘi = nr sinΘr • WhenΘr = 90, TIR occurs. • sin(90) = ___? • So........... • sinΘc = nr/ni • (Does everybody know where the sin-1 button is on their calculators?)
Total Internal Reflection HW • Read p. 403-405 • Do p. 410 # 10, 11, 16, 22, 23, 50-53