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Ordinary light and monochromatic light

  1. Apr 15, 2016 #1
    What are these?
    My notes give definitions of the two as follows
    Ordinary light: Ordinary light consists of rays of different wavelength, vibrating in all possible planes, perpendicular to the direction of propagation of light.

    Monochromatic light: Monochromatic light consists of rays of single wavelength, vibrating in different planes perpendicular to the direction of propagation of light.
    I am unable to comprehend .
     
    Last edited: Apr 15, 2016
  2. jcsd
  3. Apr 15, 2016 #2

    Borek

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  4. Apr 15, 2016 #3
    What about

     
  5. Apr 15, 2016 #4

    BvU

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    You can split up ordinary light (sunlight, for example) with a prism because there are a lot of wavelengths present (a spectrum). Monochromatic light only gives one angle of deflection (the spectrum is a single line).
     
  6. Apr 15, 2016 #5

    FactChecker

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    Light can have different colors (frequencies) or can vibrate in different directions (planes perpendicular to its direction of propagation). "mono" means one and "chromatic" means color, so "monochromatic" means one color. "monochromatic" does not mean that all the light is in the same plane.
     
  7. Apr 15, 2016 #6

    jtbell

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    That's about unpolarized versus polarized, not about whether the light is monochromatic or not.

    Ordinary light is polychromatic (= not monochromatic) and unpolarized. You can also have light that is monochromatic and unpolarized, polychromatic and polarized, or monochromatic and polarized.
     
  8. Apr 15, 2016 #7
    What does it mean to have rays of different wavelength?
     
  9. Apr 15, 2016 #8

    BvU

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    Check your colour TV: there are small green, blue and red light sources. White light you get if all three light up, yellow if green and red, etc.
    In short: different wavelengths = different colours
     
  10. Apr 15, 2016 #9
    That's okay. But what I don't understand is the light composition. Is light made up of different rays or waves? Are rays and waves one and the same thing? Because as far as I know wavelength is the distance traveled by wave in Time period.
     
  11. Apr 15, 2016 #10

    blue_leaf77

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    A light beam, or a ray of light may contain more than one wavelength. That's very common around us, in fact you can never have light which only contains a single wavelength. However monochromatic a visible light may look like to our eyes, it actually has a range of wavelengths.
    I would describe the "ordinary" light you copied into your note as the natural light under which our body is exposed to every single second, this light is not monochromatic and not polarized.
     
  12. Apr 15, 2016 #11
    Do all types of light i.e rays of light show vibration?
     
  13. Apr 15, 2016 #12

    BvU

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    There's nothing that vibrates, so: no.
     
  14. Apr 15, 2016 #13
    I am confused:frown:
     
  15. Apr 15, 2016 #14

    BvU

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    Mysterious, isn't it. OK, something vibrates far away -- at the origin of the light ray, so to speak.
    What oscillates (yes, you could use the word vibrates instead, but it confuses some folks) are the electric and magnetic fields.
    Electromagnetic radiation is propagated through the vacuum with the speed of light (Vacuum = nothing :smile:).
    I liked the video here and the picture here then there is this video and the next and a near infinity of more of them.
     
  16. Apr 15, 2016 #15
    Reading title "physics for kids!" brought a broad smile on my face
     
  17. Apr 15, 2016 #16

    BvU

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    I liked it.
     
  18. Apr 15, 2016 #17
  19. Apr 15, 2016 #18
    This one is really exciting. But sadly I am not able to understand it.
     
  20. Apr 16, 2016 #19
    Light is made up of rays and rays in turn is made up of waves. Right?
     
  21. Apr 16, 2016 #20
    Is direction of propagation of light same as direction of propagation of waves the light is made up of?
     
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