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Light. Review…. We already know that each color of light has its own wavelength & frequency. Refraction…. Each color refracts at a different angle. Heinrich Hertz. Proved the theory that violet light contains more energy than red light. Heinrich Hertz’s Experiment.
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Review… • We already know that each color of light has its own wavelength & frequency.
Refraction… • Each color refracts at a different angle.
Heinrich Hertz • Proved the theory that violet light contains more energy than red light.
Heinrich Hertz’s Experiment • When red light was shined upon the plate, few particles were emitted from the plate.
Incandescent Light • The bottom line…. The filaments in these bulbs get so hot they glow & produce light. • Details…. The filament is made of a metal called tungsten. When turned on, the electrons in the filament vibrate very quickly, creating heat. It creates so much heat that it begins to glow. A toaster works the same way!
How it works: • There is a tube, filled with low-pressure gas. • There are electrodes at each end of the tube. • Electricity passes from one electrode to the other, exciting the gas as the electricity passes through it. • The gas glows, but gives off UV light. • The phosphorus coating on the tube absorbs the UV and converts it into visible light.
Advantages Incandescent Fluorescent Very energy efficient Cheaper on the energy bill • Gives off full spectrum (Roy G. Biv) • Feels “homey.”
Disadvantages Incandescent Fluorescent Can cause eye fatigue Can lead to mental distraction Harsh colors (not homey or cozy feeling) • 90% of energy is lost as heat • Expensive energy bill