Transcript Diffraction-

DiffractionThe bending of a
wave around the
edge of a
barrier/spreading of
light waves
Remember:
Constructive Interference: IN PHASE brighter
Destructive Interference: OUT OF PHASE-dimmer
Interference
Fringes
patterns of bright and
dark bands on a screen
resulting from
constructive and
destructive interference
of light waves.
Clear, distinct interference fringes only
occur when the light wave is:
a. coherent- phase difference is constant
(same frequency)
b. monochromatic- light of only one color
(same wavelength size)
ex-laser
Multiple Slit Diffraction-occurs with
diffraction gratings which contain a large
number of parallel, closely spaced slits,
which disperse (separates) the light based
on wavelength.
Why Do We See
the Colors We See?
Reflection
Interference
Refraction
Color and Wavelength
The color of the light depends on its wavelength.
Red= longest , lowest f and energy.
Blue = shortest , highest f and energy.
The speed of light is the only factor that is NOT different
when comparing the different colors of light.
What Color We See Depends On…
• The light incident upon an object.
•The frequencies reflected and absorbed by the
object.
Color applet
Primary Colors-any three colors of light
which produce white light when combined with
the correct intensity (brightness).
Magenta
Primary Blue
Primary Red
Cyan
Yellow
Primary Green
Mixing Light is called: Color Addition
Red Light + Blue Light = Magenta Light
Red Light + Green Light = Yellow Light
Green Light + Blue Light = Cyan Light
Red + Blue + Green = White
Secondary Colors-produced by
addition of equal intensities of
TWO primary colors.
Color Subtraction:
How Would a Red Apple Appear Under….
White Light?
Red + Blue + Green = White
Apple reflects red, so will appear red.
Blue Light?
Apple reflects red, so will appear black.
What color would your opaque magenta shirt appear
to be under the following colors of light?
White
Red
Cyan
Green
Yellow
White = Magenta
Red =Red
Cyan (Green & Blue) = Blue
Green = Black
Yellow (red & green) = Red
Magenta = reflects
red & blue
absorbs green