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Course: Exploratorium > Unit 2
Lesson 5: Colored Shadows- Colored shadows: Introduction
- Build your own colored shadows: Materials & steps
- What's going on: Light travels in straight lines
- What’s going on: Human color perception
- Yellow and cyan challenge
- Yellow and cyan solution
- Further explorations with colored shadows
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Colored shadows: Introduction
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- At0:09how is there colored shadows, but also black shadows, for his arm?(8 votes)
- Because his arm is thick enough to block out the light from all three colored bulbs all at the same time. If you draw a straight line from each light through his arm and directly unto the white board behind, you will see that neither colored light can reach that space, an thus, the shadow is black there. Note that around the edges of the shadow of his arm, there are different colors. This is because, at those spaces, his arm is blocking the paths of only one or two of the colored lights (not all three).(11 votes)
- How does the green, red, and blue lights together make the color white?(1 vote)
- The combined color makes it white. When two lights make a non-white color, it is because when they mix, they cancel each other out (or the opposite?) to make white.(3 votes)
- Is something like this used for 3D movies?
or is it something else?(2 votes) - Brown and dark blue what colours gain(1 vote)
- Why is the green light bulb black when only the red light is on?(1 vote)
- How do you now the Colored of Shadows is blue,Green,red(1 vote)
- Why are the primary colors of light red, blue and green, while the primary colors of pigment are red, blue and yellow?(1 vote)
- printers are based on cyak or subtractive coloring. so cyan magenta yellow take away colors(1 vote)
- why his hand is lokking like megenta and blue color(1 vote)
- Do coloured lights form coloured shadows? Describe how you would find out for yourself.(1 vote)
- Perfect answer to your question.
http://www.exploratorium.edu/snacks/colored-shadows(1 vote)
- Is white light made out of red, cyan, and blue?
and is cyan acually yellow, so they are the three primary colors?(0 votes)- I'm sorry but white light is not made up of red, cyan and blue. People say that it's made of Red, Green and Blue, but it's actually made of ALL of the colours of the rainbow because it contains all wavelengths! And also, cyan isn't yellow! I don't know who told you that but it's wrong! Cyan is a mixture of equal amounts of blue and green light! Yellow is a mixture of equal amounts of red and green light! Remember: paint mixing and light mixing is totally different!(3 votes)
Video transcript
- [Voiceover] We have red,
green, and blue lights. Why are these shadows
not red, green, and blue? We have our three lights,
red, and green, and blue shining on the board. It looks white. When I put the pencil in and cast shadows, the shadows are yellow, magenta
in the middle, and cyan. To understand how that happens,
we can turn off the lights one at a time, so that only
the red light shines on the board making it red. Now when I cast a shadow,
it's a dark shadow, it's the one place on the board
where there is no red light. So we can think of the shadow
as subtracting red light from the board, in the position of the shadow. To understand our colored shadows, I'm going to start by
turning off the green light. This leaves a red light,
separated from a blue light by about eight inches. That'll be important to
understand the shadows. When the red light and the
blue light shine on the board they scatter off the board
and you see a megenta color. When I make my shadow, I
see two different shadows. The light from the red light
goes in a straight line and it makes a shadow here. watch that shadow as I turn
the red light on and off. So this is the shadow of the red light. And over here, this is the
shadow from the blue light. The blue light is in a different
position so it fills in the shadow from the red light. And the red light fills in the
shadow from the blue light. That's why we have red and blue
shadows in a magenta board.