wind turbine kit,
blood type test,
In art, color is very important. The color wheel is often used to explain the relationship of different colors to one another. In this way, artists know what colors look good with each other, and how to mix paint to produce more colors. All possible color combinations can be made by mixing just three primary colors with white and black. Artists use a color wheel that has the three primary colors - red, yellow, and blue - and three secondary colors - orange, green, and violet - as well as the tertiary colors that are in between, such as blue-green.
In this project, see the bright colors of the rainbow
disappear right before your eyes as you learn about the properties of
light and how we see color.
What you will need:
2 white paper plates
Cereal bowl or coffee can lid
Thumbtack or pin
Red, yellow, and blue paint*
Glass of water
* Use watercolor in a tube, wet or dry tempera, or any kind of acrylic paint
for this project. If using watercolor, choose colors marked with true red, yellow, and blue, or cadmium yellow, cadmium red, and ultramarine or cobalt blue. These colors will allow you to mix every color of the rainbow. If using acrylic or tempera, select very bright primary colors.
What to do:
Use the cereal bowl or plastic lid to trace a circle onto one of the
paper plates, then cut it out with scissors.
Using the protractor, draw seven equal sections onto the circle. This part is tricky!
First find the center of the circle and draw a dot there. Then draw a straight line from the center to the edge of the circle. Next, align the straight edge of the protractor with the
line you just drew, placing the end of the protractor right on the center of
your circle. On the curved edge of the protractor, look for a number that is close to 52 degrees, and mark it
with a dot. It doesn't have to be exact, but make it as close as you
can. Now, use the straight edge of the protractor to draw a straight line from the center dot to the dot you
just made, going to the edge of the paper circle. The angle you drew is
1/7 of the circle! Continue doing this until you have measured all of the sections. (Each section should be about 52 degrees, since a complete rotation around any circle is 360 degrees,
and this circle needs to be divided into seven parts. 360/7= 51.4).
Now, mix the paint to create every color of the rainbow: red, orange,
yellow, green, blue, indigo, and violet. Use the second paper plate as a
palette for mixing colors. Start with quarter-sized blobs of red,
yellow, and blue paint, and add more as you need it. You might need to use a little water to thin the paints
to get even consistency. Wash your brush by swirling it in the cup of water every time you switch colors. You may need to change the water in the cup after a while.
To make green, mix equal parts yellow and blue.
To make the green a bit darker, add more blue and to make it lighter add a
little yellow. Orange is made by mixing equal parts of red and yellow.
If you want a darker orange, add more red. Violet (purple) is made of equal
parts red and blue. The last color you will need is indigo, which is a
sort of dark, bluish purple. Add equal parts of purple and blue to
Now that you have mixed the paint you need, paint the sections in order
from red to violet. While painting, dip your brush in the water often to
keep the paint smooth and even in consistency. Once you have finished
painting, let your color wheel dry for a few hours.
Using a thumbtack and pair of scissors, make a
hole in the center of your color wheel big enough for a pencil to fit
Push the pencil through the hole, and spin it quickly (on a table) to watch
the colors disappear!
Light is made of all the colors in the rainbow. When it hits a colored
object, most of it is absorbed and only one color is reflected. A red
object, for example, absorbs almost the full spectrum of light, reflecting red
Our eye is able to see because of light-sensitive photoreceptor cells called
rods and cones that are in the retina, or layer of tissue in the back of the
eye. Rods and cones sense the different light waves reflected off
surfaces, then send signals to the brain. If no light is reflected, but
all colors are absorbed, that surface will look black. If no light is
absorbed, the object will look white.
When the color wheel was spinning, the colors changed faster than the
photoreceptors could communicate with the brain, so the reflection of the colors
blended and you saw white light!
Colored Light = White?
Artists mix the primary colors of red, yellow, and blue, but scientists use a different set of primary colors when talking about the visible light spectrum: red, green, and blue. These colors can be used to explain how the entire spectrum of colors mixed together makes white light. To see how this works, experiment with three flashlights and red,
blue, and green cellophane. Attach a different color of cellophane to
each of the flashlights with a rubber band. You may need someone to help
you shine all of the flashlights onto a plain white surface such as a wall,
sheet, or poster board. Position the green flashlight so that it is shining
directly onto the white surface, and hold the blue light below it, at an equal
distance away from the white surface, so that it overlaps the area that the
green flashlight is shining on. Then hold the red flashlight above the
green one, at an angle so that it lights up the same area as the green and blue
lights are shining on.
A bright white light should appear on the surface where the colors overlap. You may need to adjust the flashlights a little bit for this to happen. Try sticking your hand
between the surface and the colored lights. How many different colors do
you see? All of those colors are created by the three primary