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Rotating single slit and 2 single slits merging

  1. Feb 11, 2010 #1
    a link to my youtube page of a rotating single slit and 2 single slit's merging,comments welcome on what you think it shows,or dont show
     
    Last edited by a moderator: Sep 25, 2014
  2. jcsd
  3. Feb 11, 2010 #2
    What do you think it is or isn't showing?
     
  4. Feb 11, 2010 #3
    i know but it isnt for me to tell people,there is way to many people that have been told what to think and not how to think,iv seen way to many parrots just repeating what they have been told,and acting as if they know it all,very few seem to even bother to try there own experiment to back up or disprove the main idear,
    ps i hope i havent up set any parrots :)
     
  5. Feb 11, 2010 #4

    berkeman

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    Staff: Mentor

    I didn't see anything unusual, but I only watched parts of it. Could you please give a time stamp or two of anything happening other than simple superposition?
     
  6. Feb 11, 2010 #5
    No. You must have some motivation for doing this experiment. I see nothing extra ordinary.
     
  7. Feb 12, 2010 #6
    simple superposition
    (superposition)overlapping of waves,did any wave cancel any other wave, it was only 5.38 min long and you didnt watch it all :)
     
  8. Feb 12, 2010 #7
    motivation ? my motivation is to question things and experiment and look in to things,to think and to wonder (or ponder) if you see nothing extra ordinary then nothing more to say,thanks for your comment
     
  9. Feb 12, 2010 #8

    berkeman

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    Staff: Mentor

    You must have lots of free time, son. No, I have a very short attention span for forum posts, and a very high expectation of forum posters not to waste my time. Give me a time stamp in your silly video to look for something extraordinary, or your thread will be deleted with a misinformation infraction. I would definitely be interested if you have something to show us.
     
  10. Feb 12, 2010 #9
    We have no idea what it shows because you didn't bother to describe your setup or explain what you are doing to get the patterns. If you want some opinions you have to explain the experiments that are giving the patterns.

    Make a new video but start each part with the lights on and show the setup and explain what you are going to do to make the patterns. Then show the patterns that result. Then go on to the next setup and do likewise.
     
    Last edited by a moderator: Sep 25, 2014
  11. Feb 12, 2010 #10
    i thought it didnt need explaining 2 lasers 2 single slits (2 pebbles in a pond )one wave cancel out another,what is there to explain
     
  12. Feb 12, 2010 #11
    The interference pattern occurs on a per-photon basis. Photons do not interfere with one-another. So you would not expect interference between two lasers as the each photon still only passes through one slit.
     
  13. Feb 12, 2010 #12
    no it dont otherwise how does it do it with 1 laser and 2 slits,the first experement by young was with sunlight,it is all explaind with noncence,if you had 2 slits in water and a wave hits the slits they dont interfear,they re join as 1 wave you can see it happen with posts in water (a piear )funny thing is iv done the experiment with the lens removed from the laser (vid on youtube)and there is no expanding patterns,but banding inside the slit,iv got photos taken through a pin hole with 18 times zoom,to see the ring banding,photo through 2 slits 18 times zoom to get the lined banding,a few pic of laser with out lens through a macro mesh,
    http://www.flickr.com/photos/kevinstuartfr0st/
    thanks for your reply and time
     
  14. Feb 12, 2010 #13
    If you placed the double slit in water you would in fact see the interference, I have seen it as a classroom demonstration. It all depends on the wavelength compared to the slit size and spacing.

    1 laser and 2 slits interfere because the photon from the laser passes through both slits and interferes with itself. The same would be true from the sun, or any other source. If the photon can not travel through BOTH slits, there is no interference.

    I'm not sure of your point on lens on the laser.
     
  15. Feb 12, 2010 #14
    well you can eather look at my video of lasers with out lens,or if you want you can get a laser for a few £ or $ and try it for your self,
    (this is a video of a shallow slit and deep double slit only 6 min long but for any one that cant sit still that long 4.25 is where is starts with no lens on the laser.
    your not one of them that think that just looking affects it are you ?
    again thanks for your reply and time
     
    Last edited by a moderator: Sep 25, 2014
  16. Feb 13, 2010 #15
    So there is no two-slit interference when you take the lens off of the laser?
     
  17. Feb 13, 2010 #16
    yes there is no interference when you remove the lens,that on its own cast questions on it all,it is hard to explain but if you look at the pic on my photo page iv taken shots of laser with out lens through a macro mesh,(from a grinder)there is a grid (banding)pattern but inside the projected mesh holes,didnt want to post link again but will just for them pic
    http://www.flickr.com/photos/kevinstuartfr0st/sets/72157623369368368/
    the dark bands betwen the banded squares is the shadsdow from the wire frame of the mesh,
    again thanks for your reply
     
  18. Feb 14, 2010 #17
    I can't imagine what difference a lens makes. At most it will polarize the light, and it should work fine unpolarized. The only thing I can think of is if there is some inherent polarization in your laser based on the incident angle (and the laser was close enough to the slits), which would allow some way of detecting which slit a photon went through. That would destroy the interference patter.
     
  19. Feb 22, 2010 #18
    again thanks for your reply i have done a video because it is hard to explain but will try,get 2 newton's rings and squeese them together and the straigh lines that form is the banding,
    have to remember we are looking at a very small cross section of the whole picture,
     
    Last edited by a moderator: Sep 25, 2014
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