Light

Light is a wave! The Nature of Light What is Light? Light can 1. travel in straight lines 2. reflect 3. refract 4. transmit energy Light is a wave!

LIGHT WAVES Electromagnetic Waves—Do not need a medium Transverse wave Oscillating electric and magnetic fields

c = λf Speed of Light All EM waves travel at the speed of light (c) c = 3.00 X 108 m/s (in a vacuum) Wave speed equation is still valid: c = λf What happens to the wavelength if frequency is increased?

Decreasing Wavelength  Increasing Frequency 

Frequency, Wavelength, & Energy As the frequency of a light wave increases, so does its energy. Gamma rays are dangerous to us because they have high energy and a short wavelength (smaller than our cells!) Radio waves are harmless to us because they have low energy and long wavelengths

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Visible Light Spectrum: Visible light is the portion of the electromagnetic spectrum which stimulates the retina of the human eye. Visible spectrum wavelengths range from about 400 nm (violet) to 760 nm (red). Visible Light Spectrum: ROYGBV

Intensity of Light The inverse square law The brightness of the light decreases by the square of the distance . Like sound waves light spreads 3-D

POLARIZATION Manipulating a wave so that it only oscillates in only one plane of direction.

POLARIZATION Two ways to Polarize Light: Reflection Polarizer- blocks out all but one direction that light can travel

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POLARIZATION What is happening to the light? Explanation Fun with polarized light

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