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Thread: Prisms

  1. #1 Prisms 
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    hello

    Im new and well just wondering is there a perfect 100%? prism shape?

    most designs like triangles ect.. do not look like efficient shapes

    http://www.mathsisfun.com/geometry/prisms.html

    even a octagon squared doesnt seem good

    I would think a sphere but im reading you need straight sides?


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  3. #2  
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    What do you mean by “efficient”? :?

    A prism in mathematics (geometry) is different from a prism in physics (optics). The webpage you are looking at is about mathematical prisms. In optics, however, a prism is simply any transparent object with a high refractive index used to refract light; what shape it is depends on what you want it to do with your light.

    So yes, an optical prism can be spherical if you like. But you did not say what your experiment wants to achieve with light, so I can’t say what the “ideal” shape of prism for your purpose might be.


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  4. #3  
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    Quote Originally Posted by JaneBennet
    What do you mean by “efficient”? :?

    A prism in mathematics (geometry) is different from a prism in physics (optics). The webpage you are looking at is about mathematical prisms. In optics, however, a prism is simply any transparent object with a high refractive index used to refract light; what shape it is depends on what you want it to do with your light.

    So yes, an optical prism can be spherical if you like. But you did not say what your experiment wants to achieve with light, so I can’t say what the “ideal” shape of prism for your purpose might be.
    I believe though that they mean ideally when talking in optics that you are dealing with a bar of clear light transmitting substance, with a perfect triangle shape.

    There are other definitions that could apply but ideally when you say prism in optics you are talking about a perfect triangle shaped object.
    But you are correct we use the word prism to identify many light refracting objects effects on light, not in a perfect triangle shape. However I believe we use the word prism to describe the effects the object has on light, not the shape of the object.

    It is like the word special. If I said "Jane you are special", you would assume that you are unique and gifted. But definitions of special exist that could mean I think you are weird or peculiar. Like the kids on the special bus.

    But if I used it or meant it in that sense, I would be committing a low blow, or being deceitful, or cowardly. If I did not highlight, that I meant it that way.

    What bus did you take Jane? Ha-ha.


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    William McCormick
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  5. #4  
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    Please don't use seriously meant questions for your petty personal crusades.

    Indeed, in optics, prisms are defined according to their usage, not their shape. Here is an example that is not triangular at all. Also note the references mentioned there: Nicol prism
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    Quote Originally Posted by Dishmaster
    Please don't use seriously meant questions for your petty personal crusades.

    Indeed, in optics, prisms are defined according to their usage, not their shape. Here is an example that is not triangular at all. Also note the references mentioned there: Nicol prism
    That is my idea of camaraderie, I live and work with a tough group.

    Why do you think I would want to attack someone? I like Jane. She is more fun when she has a problem.

    The prism was originally a three sided object in optics. A perfect triangle in bar form. The same effects were noticed in other shapes, and these effects were prismatic effects. I would be the first to admit that many call any shape with equal parallel sides a prism. But in optics a prism was a prism. If you were talking about an octagon prism then you would say an octagon prism. You could only assume the triangular prism.






    But in optics if things have changed, I can too.


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    William McCormick
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  7. #6  
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    Take a look at something.

    http://microcosmos.uchicago.edu/micr...troduction.htm


    Now take a look at Wikapedia on prisms. That is your link below.

    http://en.wikipedia.org/wiki/Nicol_prism

    Someone is a little off their time line.


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    William McCormick
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  8. #7  
    Moderator Moderator Dishmaster's Avatar
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    So, what is your point? A prism can achieve many things. One is to split up polychromatic light into monochromatic portions. This can be done with one prism, yes. The further diversification into different polarisations is another thing. This can be done best with monochromatic light using e.g a Nicol prism. Both rays still have the same wavelength, but different polarisations.
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  9. #8  
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    Quote Originally Posted by Dishmaster
    So, what is your point? A prism can achieve many things. One is to split up polychromatic light into monochromatic portions. This can be done with one prism, yes. The further diversification into different polarisations is another thing. This can be done best with monochromatic light using e.g a Nicol prism. Both rays still have the same wavelength, but different polarisations.
    They were claiming that the first prism was in 1829, that is not so.

    They have been using prisms long before Newton. A normal perfect triangular prism does polarize light to some degree. It removes certain zigzagging white light and creates separate rays of different color light. You can also spread out a single color light with a prism as well.

    That "Nicole prism" is not even a prism. That is a multi density device not at all a prism. That is just more bad science.

    But my point was that an optical prism was the perfect triangular shaped bar.

    A polarizing device can slow up and speed up light rays, creating light, or different light, then the source rays. Source rays that are often not light.
    Polarizing devices are like a prism but not a prism. Polarizing devices usually have the light shot down the long tubular structures of the polarizing device.
    Very different then a prisms use. Where you send the rays across the walls or the tubular, bar shape.


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  10. #9  
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    thanks for the good feedback guys 8)

    I ment 100 % efficient at containing light and keeping it in(oh and yes i understand exactly 100% is not possable on many things)

    I dont want to tranfer the light but build on it x2 ect :wink:

    even geeks do the bashing now days too?

    wears flame suit 8)
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  11. #10  
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    That's basically how a laser works, although they use a pair of mirrors. [url=http://en.wikipedia.org/wiki/Laser_construction]Wikipedia article[url]
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  12. #11  
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    Quote Originally Posted by Dishmaster
    So, what is your point? A prism can achieve many things. One is to split up polychromatic light into monochromatic portions. This can be done with one prism, yes. The further diversification into different polarisations is another thing. This can be done best with monochromatic light using e.g a Nicol prism. Both rays still have the same wavelength, but different polarisations.
    Not to be a pain or stickler or anything. However I was thinking about it. And I am sure that they created a polarizing device long before 1829.

    You can get those same effects with two bars of translucent material up against one another. The slight air gap between them will cause, the light to look as if it is bouncing off the walls of the bar, you are emitting light into. And yet because of the proximity create a refracted beam of light into the adjoining bar.

    They have had me hoping, lately. I just have not had a chance to get some experiments going. I have a list in my mind. I just cannot get down there to do them. I will do some experiments with adjoining translucent bars. They create that "ordinary, extraordinary" beam.

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    William McCormick
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  13. #12  
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    These are some quick shots I took just so you can see that this is nothing Newton did not experiment with. And to be honest I doubt if Archimedes did not work with this.

    These guys were making light go around in circles. Changing it from white to colored light. I am sure they put two prisms together and created "ordinary and extraordinary" light rays.

    It all depends upon the angle you can make the rays equal or you can favor either ray. To make it the dominant ray.








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    William McCormick
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  14. #13  
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    thanks again

    I dont think people understand what im hinting but thats ok I want to take credit if my idea of unlimited clean power the likes no one has seen can come true

    maybe prisms are not the ideal thought here

    oh and im sure achamedies made highly polished brass to redirect and refract light thousands of years ago :wink: ,people have been quiet smart since walking powers :wink:

    or even with crystals they found

    but a prism doesnt have to be traslucent right? :?

    thanks william ,im not sure im hinting too spectrums :wink: but thanks
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  15. #14  
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    I think your point was answered by someone.


    The property you want is best represented by a laser.


    Here is a link:
    http://en.wikipedia.org/wiki/Laser#Design


    On the other hand, refraction is related to the frequency of light.

    "The frequency of light" determines the color of light. Checkout the frequency spectrum.

    Refraction is related to the speed of light in two media. As its formula dictates. We can go mathematical if you need to see the relationship.
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