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Odal
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Is it possible to modulate light as it is to modulate sound.?That is, taking "white" light and changing its color without using a filter or another object like a prism?
Did you do a search on "Optical Modulators"? Does this question come from personal curiosity or did you have an application in mind?Odal said:Is it possible to modulate light
That's how a color LCD display works, but not how an LED display works...Odal said:That is, white light goes through these colored filters and get the color of the filter, and that is exactly what I find intriguing. Could it be possible, however that is done, to produce colors without those filters?
I am afraid I do not see how that is relevant. I do not know enough about the differences between both. Do you mean to say that LED screens already do what I am asking about? If so, I would be very curious how it is done.berkeman said:That's how a color LCD display works, but not how an LED display works...
Red, green and blue LEDs are used to generate the light. They do not start with white light and filter the light. So colored LEDs generate their colored light in a fundamentally different way compared to colored incandescent bulbs. And I thought that was what you were looking for...Odal said:I am afraid I do not see how that is relevant. I do not know enough about the differences between both. Do you mean to say that LED screens already do what I am asking about? If so, I would be very curious how it is done.
It is certainly very interesting, but what I make of it still does not answer my question. I may be wrong but this is how I understand electro-luminescence. Crystals when put under electric current produce colored light. The color is apparently linked to the kind of crystal. If I am right, then it is the same thing as having white light going through a colored filer, only in the case of leds, it is the filters themselves that give off light?berkeman said:
Odal said:Crystals when put under electric current produce colored light.
No, it is fundamentally different. Have you learned yet about how electron energy level transitions in atoms can give off photons?Odal said:If I am right, then it is the same thing as having white light going through a colored filer, only in the case of leds, it is the filters themselves that give off light?
berkeman said:No, it is fundamentally different. Have you learned yet about how electron energy level transitions in atoms can give off photons?
First can you say what you mean by "crystals"? Can you post some links to the reading you have been doing about crystals generating light? Thanks.Odal said:please let us keep to crystals
The Wikipedia article in your previous posts. Again I apologize for my imprecise terminology, it refers to different materials used in the diodes. Here is a quote from this article:berkeman said:First can you say what you mean by "crystals"? Can you post some links to the reading you have been doing about crystals generating light? Thanks.
Yes.Odal said:The theory says that white light (or sunlight if you prefer) is a mix of (all) colors.
Yes.Odal said:colors from a tv screen for instance, come from Red Green Blue
Yes.Odal said:we can change how a sound sounds
You are not seriously expecting an answer?rootone said:Yes.
Yes.
Yes.
And?
I was expecting a question,Odal said:You are not seriously expecting an answer?
I have trouble taking your remark seriously, and I would not know how to respond without rehashing the whole thread.rootone said:I was expecting a question,
Well, we are trying to help you, and trying to determine your background and level of knowledge.Odal said:You are not seriously expecting an answer?
I have been reading for years on the subject, even though the last time I had formal lessons in Physics was in High school, in the 60's and 70's.berkeman said:Well, we are trying to help you, and trying to determine your background and level of knowledge.
Please do some reading and then tell us why incandescent lights are fundamentally different from LED lights. That's a good start. Thanks.
Odal said:the last time I had formal lessons in Physics was in High school, in the 60's and 70's.
And I take you to use your logic instead of mindlessly repeating what is in textbooks. My question is very simple and you did not answer it.pinball1970 said:I want to take you to the start then
There is a difference between "colour" and "light" in the sense you are talking about - they are not the same thing. Colour is a process not a thing in itself.
A light source (say the sun) hits an object (say a flower) some of that light is absorbed and some is reflected into your eye which are received by specialized cells in your eye, this stimulation is relayed to the brain where a "colour" is assigned. You "see" it. There are many steps to get from the light source to the picture in your brain. White light is all the visible frequencies you are able to detect ROYGBINV. To change the "colour" of any individual light you would have to change the wavelength as has been mentioned
@Odal It may be a good idea for you to rewind and start again here. I know of no one on PF who's more helpful and co operative than @berkeman so I can assure you he is trying to help and not just to argue.Odal said:I have been reading for years on the subject, even though the last time I had formal lessons in Physics was in High school, in the 60's and 70's.
I have read the article you kindly linked and gave my opinion. I take your remarks very seriously, but I cannot take any remark seriously, not when it shows a complete disregard of what has been written in the thread.
That question is actually meaningless; you would need to make it much more clear what you actually want to know.. You are annoyed because you are dissatisfied with the answers you are getting.Odal said:You can chant all the conjurations you can think of, but here is again my simple question: is it possible to produce colored light without already colored objects or filters?
I am very grateful to you for answering my question directly instead of hiding behind common knowledge that is quite irrelevant to the issue here.sophiecentaur said:@Odal It may be a good idea for you to rewind and start again here. I know of no one on PF who's more helpful and co operative than @berkeman so I can assure you he is trying to help and not just to argue.
Your OP has only one real answer to it and that answer is no. That is not to say that there is not a process that takes light in of one frequency and dishes out the 'same' light with a different frequency (The word Colour only has meaning in the context of Human Vision; you have to use the words Spectrum, Frequency or Wavelength, which can a actually be measured.
Colored light refers to visible light that has a specific wavelength and appears as different colors to the human eye. On the other hand, colored objects are physical objects that reflect certain wavelengths of light, making them appear as a specific color.
Colored light plays a crucial role in how we perceive the colors of objects. When colored light shines on an object, the object absorbs certain wavelengths and reflects others, which we then see as its color. The color of the object can also appear different under different colored lights.
Yes, colored light can change the color of an object. When colored light shines on an object, the object will absorb certain wavelengths and reflect others. Depending on the color of the light, the object's color may appear different to our eyes.
We see colors through the process of light absorption and reflection. When light hits an object, the object will absorb certain wavelengths and reflect others. The reflected light enters our eyes and stimulates our color receptors, allowing us to see the object's color.
Objects appear black in the absence of light because they are not reflecting any wavelengths of light that our eyes can detect. On the other hand, objects appear white when they reflect all wavelengths of light, making them appear colorless to our eyes.