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Results and Observer

  1. Mar 29, 2009 #1
    During a quantum experiment there is an observer and you get a result. You perform the same experiment without an observer and get another result. Is this true?

    The link below is very good at explaining, it's animated too but that's good, it is fun to watch.

    Again, can an observer by observing change the outcome of the experiment or not?
    Last edited by a moderator: Apr 24, 2017
  2. jcsd
  3. Mar 29, 2009 #2


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    Unfortunately, this video is from a very dubious movie.

    To address your question, say you put a photographic film as the detector screen, but you don't observe the result. Do you think it makes any difference in the result you see on the film just because you observe it later?

    What you are confusing with, I think, is an observer or the ability to observe of the exact path through the double slit. This is a different question than what you asked. I would suggest that you browse through the various threads in here because this issue has been discussed ad nauseum.

  4. Mar 29, 2009 #3
    Okay but it is a good illustration.

    That is not what I meant. I mean that you observe the slits, what is happening to the electron? You shoot one at a time. You saw in the movie, shoot one at a time and you get an interference pattern but if you observe what is happening at the slits then it behaves like a particle.

    That's right, sorry for me confusing you. I have read about this and seen different movies. Maybe you have heard of the theoretical physicist Michio Kaku. He showed this experiment once. He used a laser. He took dust, or something resembling to dust, and powdered the air, don't know how to say it.
    Anyway, it showed that before the slits the photons behaved as particles and after the slit it behaved as waves. How did he know that? The dust in the air made it possible so see the laser beam before the slits but not after. We can't see waves of light and the pattern was an interference pattern.

    I will search on the forum about this. Thanks for your help.
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