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B Can a light beam stop in air?

  1. Oct 28, 2018 #1
    is it possible, i mean can we hold it at a certain distance we want ?
     
  2. jcsd
  3. Oct 28, 2018 #2

    BvU

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    Hello Ramazan, :welcome:

    What kind of air are you thinking of ?
     
  4. Oct 28, 2018 #3
    i consider it inside of the atmosphere, on earth. But in vacuum i guess it doesnt matter. Light can travel in both mediums, right?
     
  5. Oct 28, 2018 #4

    BvU

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    Yes, it definitely can.
    My question was more if you consider fog and rain as air.

    Light gets scattered by air molecules, but that's not really 'holding it at a certain distance'.

    Actually stopping a ray of light isn't really possible without putting something in its way, to absorb it.
     
  6. Oct 28, 2018 #5
    How can you say that isnt really possible ? what do you relly on ? can you show me any proof of it..thank you btw
     
  7. Oct 28, 2018 #6

    Nugatory

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    Light is an electromagnetic wave that behaves according to Maxwell's equations. These equations do not allow "standing still" as a solution.
    (There is such a thing as a "standing wave", but that doesn;t sound like what you're thinking of).
     
  8. Oct 28, 2018 #7

    Dale

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    We receive light from galaxies billions of light years away, and the CMBR from even further.

    We see it as long as there isn’t anything between us and the distant galaxy to absorb the light, as @BvU stated
     
  9. Oct 28, 2018 #8

    Mister T

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    We're relying on the laws of physics, which are consistent with every observation made and every experiment ever performed.

    If you were to ask this question in some place other than a physics forum you may get a different answer. But when you ask in a physics forum the answers are based on physics.
     
  10. Oct 28, 2018 #9

    ZapperZ

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    What I want to know is if you are simply focusing on just regular, ordinary, atmospheric air, or do you also include ANY gas phase. Lene Hau has stopped light in Na gas back in... what, 2001? Not only that, she managed to hold it for some time, and then "released" it back!

    Or did you miss this news?

    Zz.
     
  11. Oct 28, 2018 #10
    Just let the air move with the corresponding speed in the opposite direction in this distance.
     
  12. Oct 28, 2018 #11

    phinds

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    Well, the problem with that is that you can't get the air to move at the speed of light.
     
  13. Oct 29, 2018 #12

    jbriggs444

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    The speed of light in air is slightly less than c. So the possibility exists to get some "air" moving very close to c one way and shoot light through it in the opposite direction.

    Easier yet, shine a flashlight at the wall and adopt a frame of reference in which the Earth is already moving near c. Bingo, light stopped in air.
     
  14. Oct 29, 2018 #13

    BvU

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    @Ramazan Duzgun : does any of this help you ? (other than showing multi-interpretability of your original question :wink: )
     
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