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Scientists claim that an object’s color is a result of the object absorbing all colors of the spectrum (a light being a source of the entire spectrum), except for one color, which bounces off, thus giving the object its color. (A white object does not absorb any color, a black object absorbs all colors.)[citation needed]
Now, you can see for yourself that it is not true. Ask an adult to help you take a thin sheet of colored plastic (for example, the cover of a plastic looseleaf) and hold it under certain light conditions. Observe the colored shadow on the floor. According to scientists, the floor absorbs that color, so it should not make any difference what is held on top of it. Tiyuvta!
That is called a reflection.
SDD,
The color you see is dependent on the wavelengths of light hitting the object. For example if you shine a “white light” which consists of Red, Green and Blue light onto a surface that absorbs red light the surface will reflect back green and blue and you will see the surface as purple. (Green + blue= purple I think) if you use a plastic filter that only lets green light through to the surface you will see that surface as green. No contradiction at all.
SDD,
What I was saying in my comment was that the premise your question was based on was false. The reason why we see an object as a certain color depends on both the Color of the light shining on it and which colors it reflects back.
For example the reason you see a purple object as purple when you shine a white light on it is because the object absorbs the red light and reflects back the blue and green. Blue and green mixed together makes purple. I you held a piece of plastic over the surface that only let’s green light through (like a transparent green folder) the light reflecting of the surface of the object will appear green.
Your question was assuming that in the case of a purple object the surface of the object was absorbing all of the colors that aren’t purple including green.
Red and blue make purple. Blue and green make turquoise.
The reason why light appears a certain color when it strikes a certain element is because electrons have energy levels which can be segregated by something called a “band gap”. the color of light is an indication of the energy level that its photons carry (measured in electron Volts or eV) as well as being directly correlated to its wavelength. When a material has a particular band gap the electrons in it absorb a specified amount of energy from the light and the rest of it is transmitted or reflected. You can predict what color an object will be, as well as if its crystalline form will be opaque or transparent based on its band gap classification. A laser beam works off of these principles. If it were not true, we wouldn’t have lasers.
Curiosity,
Thanks for the correction. So substitute turquoise for purple in my example or green for red. Point is that the observation made in SDD’s question does not contradict anything.
White light is made of the “primary colors”. What I’m saying is the reason why you see a purple surface as purple is not because purple light is being bounced back. Rather it is because green light is being absorbed so red and blue are bouncing back and red and blue makes purple. Therefore if you would shine a light through a filter that filters out everything except blue light then the blue light will reflect back and you will see a “blue shadow” under the filter. The surface wasn’t absorbing the blue light it was just mixing it with red so you saw purple. The premise that your question is based on assumes that the surface was absorbing the blue light.
You as not addressing his question at all. You are just washing it over with more scientific trivia.
The question is that he noticed a color reflecting off an object of a different color. The answer is that although an object absorbs all other colors it doesn’t completely absorb it. If you overload it with a color you will see that color. Even a black surface will shine with enough light shone on it. Black velvet is an exception, which is why or is used in photography.
HaLeiVi, black velvet is not the exception. Everything known to man, except a black hole, has some reflectiveness. The closest thing we have to an out right blackbody with zero emmisivity is Vantablack, which is made of vertically arrayed carbon nanotubes, but it still reflects 0.035% or so of light.
But velvet is less reflective than other fabrics.
Halevi,
You said “The question is that he noticed a color reflecting off an object of a different color. ”
And my answer was that the reason he saw the “other” color when he applied a filter was because the original color he was seeing (when he was shining unfiltered white light) was a mix of more then one of the “primary colors” that make up white light…. (in my example blue and red were being bounced back so he perceived it as purple he was assuming that the red and blue light was absorbed so if he shined a light through a blue filter he was surprised that blue light bounced back, but blue light was being bounced back all along. Now if he had tried to shine a green light on a purple surface the surface would appear more or less black.
It would be the same if you shined light of any one of two primary colors on an object that is the third color for example if you shine a green or blue light on a red surface the surface will appear black as well).
That’s why I was saying that the premise his question is based on is simply wrong.
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