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Thread: Optical Density

  1. #1 Optical Density 
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    We've all learned in school how refraction of light takes place when it enters a medium which has relatively different optical density than the medium which it leaves.

    I've a question which hasn't been answered: What is the cause of optical density?
    Please answer.


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  3. #2  
    Forum Junior Zitterbewegung's Avatar
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    Electron density of the material as well as the nature of the chemical bonds.


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    It is also a matter of effective cross sections for the photons to hit the particles. So, it is a combination of the 2-dimensional distribution of particles that photons can hit, where they are absorbed, and the thickness of the medium.
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    Quote Originally Posted by Dishmaster
    It is also a matter of effective cross sections for the photons to hit the particles. So, it is a combination of the 2-dimensional distribution of particles that photons can hit, where they are absorbed, and the thickness of the medium.
    Thickness? Like in "Dicke"? This is important for the absorption but how does thickness play a role in the index of refraction?? Absorption yes, but refractive index................
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    Quote Originally Posted by Zitterbewegung
    Quote Originally Posted by Dishmaster
    It is also a matter of effective cross sections for the photons to hit the particles. So, it is a combination of the 2-dimensional distribution of particles that photons can hit, where they are absorbed, and the thickness of the medium.
    Thickness? Like in "Dicke"? This is important for the absorption but how does thickness play a role in the index of refraction?? Absorption yes, but refractive index................
    I was talking about the question on "What is the cause of optical density?"
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    I dont think that a small glass shard has different optical density than a glass slab.

    Anyways, I want to know how snell's law can be derived using the data about electron density and effective cross section. Well, I had guessed Zwitterbewebung's answer myself.
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  8. #7  
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    Hello? any answers?
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    Quote Originally Posted by PritishKamat
    Hello? any answers?
    It is the shape of the shard that matters. Just like the shape of lens matters.

    Look at how lenses work. The thin part of the lens repels light rays to the thicker part of the lens.


    The thinner part of the lens has more surface to volume. The innards of the lens accelerate the ambient radiation passing through. The surface slows them. The electrons move to volume of accelerating material.

    Where ambient radiation is moving fast, you have less, repulsion. Each electron is there for a shorter period of time. Leaving less and less of its repulsive charge. Where you have voltage or an abundance of electrons you get a slowing, of ambient radiation and each electron has more time to leave its repulsive charge.



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  10. #9  
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    I'm actually looking for the reason for refractive indices and not the factors affecting the end results of refraction
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    Quote Originally Posted by PritishKamat
    I'm actually looking for the reason for refractive indices and not the factors affecting the end results of refraction
    I gave it all to you. The whole picture of lenses.

    Did you ever see a beveled mirror. That is pretty wild. It makes you wonder. Because when you look into the mirror at something behind you. You see, that the object turns into two objects, near the bevel.

    The glass acts like a lens and pulls the light into the deeper portion of the glass. You should experiment with that. It opens up some cool questions about ambient radiation.

    http://www.Rockwelder.com/WMV/coinwaferhq.wmv

    Look at a mirror and how it absorbs light. Or accelerates light.

    That wafer is also invisible to dark heat. It passes right through the wafer. It is pure silicon though. That is what pure silicon is known for. That is why they use quartz in radiant heater elements.

    A radiant heater, will not heat the silicon wafer, however you can feel the radiant heat through the wafer, a foot away from the wafer almost burning your face. I thought that was pretty wild. The wafer stays ice cold.

    A friend of mine that worked for a computer company came over the house and brought the latest stuff that they were engineering. Many years back. In computer technology. He brought the micron blow ups of the chips. So that you could see the individual transistors. It was interesting. He let me keep a wafer. It is wild.

    He does specialized correctional engineering on the processes. They only yield a percentage of the chips form a large wafer. Sometimes only 30 to 40 percent of the chips are any good.








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  12. #11  
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    You still didn't get my question. Ok, agreed, that in glass the velocity of light is less than in air and that is what is applied in lenses. I'm asking, why does glass refract light ? Is it some internal property? what is that internal property? How can I deduce Snell's law of refraction from that?
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    Quote Originally Posted by PritishKamat
    You still didn't get my question. Ok, agreed, that in glass the velocity of light is less than in air and that is what is applied in lenses. I'm asking, why does glass refract light ? Is it some internal property? what is that internal property? How can I deduce Snell's law of refraction from that?
    In glass the velocity is higher then in air. The thicker part of the glass accelerates ambient radiation.

    The problem with sending light through glass over a distance is that it is like in the depths of the ocean. Light is accelerated to a faster then light speed, and disappears. You can also have over a distance, in optic fiber, an opacity problem, that you do not get with a single quality lens, under an inch thick.

    So you either have to over saturate the glass like in fiber optics, or you do not get it to go very far. I believe Verizon went with an Ultra Violet light, approaching the x-ray band. But for short runs they probably could have gotten away with any light.

    Air on the other hand tends to slow light or rays capable of being seen as light, once slowed. Air refracts light nicely, like on a desert. Or over a hot road.
    When you see a mirage you see a density of air different then what is surrounding it. It acts like a glass lens.

    It is the surface voltage of each different object. Even if the object is just a super hot gaseous area. When ambient radiation hits the surface, it turns to the least abundant with electron area. It takes the easiest path. That can often be the most dense area, within the new object it hits.

    You can take a flat window pain and look through it on a diagonal. And you do not see any distortion. So we know it is not the angle that light hits the glass alone that counts. But the density of the glass.

    But you cannot rule out the two differing angles of the glass, on that alone.


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  14. #13  
    Forum Junior Zitterbewegung's Avatar
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    In glass the velocity is higher then in air. The thicker part of the glass accelerates ambient radiation.
    WOW!! I did not know that glass can accelerate light. Thank you for this fantastic insight.
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  15. #14  
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    In glass the velocity is higher then in air.
    Are you crazy? Sorry for being direct, but, are you crazy?
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    Quote Originally Posted by Zitterbewegung
    In glass the velocity is higher then in air. The thicker part of the glass accelerates ambient radiation.
    WOW!! I did not know that glass can accelerate light. Thank you for this fantastic insight.
    I do not know if you are being facetious or not?

    However if you look at it honestly. Glass and water are very much alike. And you may note that water has an unbelievable ability to absorb light. Some may say disperse. Some may say, opacity.

    I say, that water accelerates light just like a solid object. A solid object that does not let light pass through, like a steel plate accelerates light, to a black or dark undetectable radiation, by human standards.

    Go deep enough into the ocean and all the light disappears. It has just accelerated to a speed that is not light. But rather dark radiation.

    Night vision works on this principle. It slows down the dark radiation, that carries with it a picture of what is there.

    Acceleration is what makes light go away. You stop light enough it will create a laser, and blow a hole through metal.



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  17. #16  
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    I do not know if you are being facetious or not?
    [frantically looks for the "sarcasm"-tag, doesn't find it, gives up]

    Nooooooooooooooooooooo.................. I was just kidding.

    Jesusfrigginchristsittingonahotplate I never, ever before heard such a giant, nonsensical load of bullsh!t.

    Consider yourself ignored in the future..................
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