BellworkBellwork What is a photon?What is a photon?* Turn in the EM Vocab * Turn in the EM Vocab

Assignment *Assignment * A wave packet of an EM A wave packet of an EM

radiation.radiation.

Today’s AgendaToday’s Agenda Light Polarization NotesLight Polarization Notes Lab ExtensionLab Extension Color NotesColor Notes

Light PolarizationLight Polarization Light PolarizationLight Polarization: The : The

alignment of EM waves where alignment of EM waves where their electric fields are their electric fields are parallel parallel

Note: This is different from Note: This is different from electrical polarization electrical polarization (sticking a balloon to the (sticking a balloon to the wall)wall)

Light PolarizationLight Polarization

Polarized Light

Light Polarization• Lightbulb – Nonpolarized• Smart Board – Split polarized• Monitor – Polarized

Lab Extension: The Lab Extension: The PrismPrism

Shine sunlight through the prism 50 Shine sunlight through the prism 50 cm off the ground on to a white cm off the ground on to a white sheet of paper placed on the ground.sheet of paper placed on the ground.

Draw the colors and bandwidths of Draw the colors and bandwidths of each coloreach color

Make Make fivefive observations of your observations of your findings. (colors, orientation, findings. (colors, orientation, relative band widths, etc.)relative band widths, etc.)

Colors4/28/14

Are you ready for a pop test?

Types of Color Blindness

Type DenominationPrevalence

Men Women

Monochromacy Achromatopsia (B/W) 0.00003%

Dichromacy

Protanopia (R/G) 1.01% 0.02%Deuteranopia (R/G) 1.27% 0.01%Tritanopia (B/Y) 0.0001%

Anomalous Protanomaly (R/G) 1.08% 0.03%Trichromacy Deuteranomaly (R/G) 4.63% 0.36%

Tritanomaly (B/Y) 0.0002%

Different forms of color vision deficiency

Normal, Red/Green (2), Blue/Yellow

The Color Spectrum• R – Red (longest wavelength / lowest frequency)• O – Orange• Y – Yellow• G – Green• B – Blue• I – Indigo• V – Violet (shortest wavelength / highest frequency)

White Light • White Light: Is the combination of all of

the colors of light (sunlight)

The Color Spectrum

Pigments

• Pigment: A material that selectively absorbs colors of light

Color by Transmission• Some light is

absorbed while other light is transmitted

Color Addition (Light)• Primary colorsRed, Blue, and Green• Combining colors (adding the primaries

together)Red + Green = YellowRed + Blue = MagentaBlue + Green = CyanRed + Green + Blue = White

Color Addition

Color Subtraction (Paints)• Primary colorsYellow, Red (Magenta), Blue (Cyan)• Combining colors (adding the primaries

together)Yellow + Red = OrangeYellow + Blue = GreenBlue + Red = Purple

Color Subtraction

Reflection• White –

reflects all light

• Black – absorbs all light

Color by Reflection

Color by Reflection• Illuminated with

white light • The object absorbs

all of the colors and reflect only yellow or green

Addition and Subtraction

Light Scattering• Light Scattering: the

deflection of a light ray from a straight path

(Rayleigh Scattering)

Light Scattering• Why is the sky blue and sunset red?

Blue Sky

Sunsets