Colors of Light Notes
Vocabulary:
White Light- is not a single color. It is made of a mixture of the 7 colors of the rainbow
Wavelength- light travels in waves, different colors have different wavelengths- how
long or short they are
Prism- a tool that uses refraction to spread out the different wavelengths that make up
white light
Refract- the bending of light
Reflect- to bounce off
Absorb- to take in
Primary Colors of Light- Red, Blue, Green
LIGHT
The major source of light on earth is
the sun. Other sources are fire, light
bulb (flashlight & lamp), light filtered
with other colors (ex: red light bulb,
red lamp shade, red tinted glasses)
COLOR
The sun gives off white light. White light is a
combination of the 7 colors of the rainbow:
ROYGBIV
Other types of lenses
that refract light:
eyeglasses,
sunglasses,
telescopes,
microscopes
A prism can be used to refract
(bend or split) the white light
into the 7 colors.
What We See
• The color an object
appears depends on the
color the object reflects.
Example: a red book ONLY
reflects red light, so we see
the book as being RED
• White objects
reflect ALL colors of
light because when
they are all mixed
they make up all
colors.
• Black objects absorb
all colors of light
because we don’t
see any color.
Red
notebook
We see the color of
something because
that color is
reflected (bounced)
into our eyes. All
the other colors of
white light are
absorbed (taken in)
into the object so
we don’t see those
colors.
More about Lenses
•
•
•
•
•
•
•
•
•
A lens is a curved piece of glass or plastic designed to refract light in a specific
way.
Lenses are used in glasses and contacts to help correct vision.
They are used in telescopes to help view items that are far away.
They are used in microscopes to help view very small items.
Another way to classify lenses is by the curve of the glass on each side of the
lens.
There are terms used to describe each side. Then the two sides are combined to
come up with the name of the lens.
Convex - A convex lens is one where the center of the lens is thicker than the
edges.
Concave - A concave lens is one where the center of the lens is thinner than the
edges.
One way to remember the difference between the two lenses is to think of
"caving in" with the concave lens
Refraction
•
•
•
When a light wave moves from one medium (like air) to another medium (like
glass) the light rays are bent. This is called refraction.
By using refraction, lenses can bend multiple light rays.
Most of the lenses we use in everyday life are designed to bend light rays to a
specific focal point where items will be in focus (clear).