Elenco LIGHT - Manual (Page 12)

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Light in Our World
When light hits a glass surface at a wide
enough angle, all the light is reflected. Fiber
optic cables have arrays of flexible glass fibers.
In these cables, light rays move through by
bouncing along the inside walls at wide angles,
and can travel great distances. Light moves
through the cable even if it is bent a little, but if
there is a tight bend then most of the light will
be absorbed instead of reflected forward.
Translucent materials, such as the tower and
egg LED attachments in this set, allow some
light to pass through but scatter it around.
Color
The things around you have different colors
because they reflect the colors that you see,
while absorbing the other colors. Light
produced by the sun or a light bulb is called
white light. White light is not really a color itself,
but is a mixture of all the colors seen in a
rainbow.
White light shines on an orange. All colors in
the light are absorbed except orange, which is
reflected off. The reflected orange light
reaches our eyes, so we see it as having
orange color.
White light can be split up into its different
colors. This happens when light passes
between different materials, and the different
colors in it are bent by different amounts. You
can see this by viewing white light through
prismatic film, as you do in project 67.
Sometimes water in the air can bend sunlight
by just the right amounts, and make a rainbow.
Color filters allow one color to pass through,
and absorb the other colors. When you look
through a red filter, everything looks red (or
black, if there isn’t any red in what you are
looking at). This set includes red, green, and
blue filters, so try looking through them.
Any color of light can be made, by mixing
different amounts of red, green, and blue light.
Mixing equal amounts of these colors
produces white light. If you look at a TV screen
with a magnifying glass, you will see it actually
consists of tiny red, green, and blue lights,
using different intensities to make all the
colors.
This set includes several LEDs (D1, D6, D8,
and in U22) with different colors. The color
emitted by an LED depends on the material
used in it. LEDs are more energy-efficient than
incandescent light bulbs, can be made smaller,
and last longer.
The LED in the color organ module (U22)
contains separate red, green, and blue LEDs.
The color organ can combine these colors to
make yellow, cyan, purple, and white, as
shown in project 6. The color organ does not
allow you to adjust the amount of each color.
In project 49, several colors are mixed together
on a spinning disc.
Red
Green
Yellow Magenta
Blue
Cyan
White
Orange
Orange reflected light
White light beam
White light beam
Red filter
Red light beam
Cable slightly bent
Cable with
tight bend
Light beam
(full strength)
Weak light beam