Ive been thinking a lot about Young's double slit experiment lately and have even considered attempting to reproduce some variant of it. Ive seen videos on youtube and feel like i have a good grasp of the experiment and how to create an interference pattern pretty simply at home, however i was curious to know if an observed-instance of this experiment was a reproducible effect, basically, is there a means of forcing the observational state where the photons would act as particles and create 2 lines instead of acting as waves? Ive seen plenty of videos showing the interference patterns, but literally none showing the detection at its particle state. The experiment states, and was proven, that both instances are a possibility correct? what variable effects this, can it be reproduced at home? (Ive been told observation, may even count as interaction with the air, or particles in it, so would performing the experiment under vacuum produce better results?)

Im willing to spend a fair amount here on making a demonstrative model. My basic setup was a laser spaced with a 2 slit light blocking surface, spaced from a high resolution camera with the pattern directed into the lens, my hope was to sort of map the light intensity the pixels were receiving. i own cnc mills, laser cutters and 3d printers, im fairly confident in my accurate build ability here.

Thanks in advance!

  • $\begingroup$ I'm not sure what you want. Take a look at Figure 1 in this paper. Is that the kind of thing you want to reproduce? $\endgroup$ – garyp Mar 25 '18 at 22:20
  • $\begingroup$ Well, i would like to reproduce that interfercne pattern, But also the pattern when the photons act as particles and not waves. i think this photo demonstrates both states. google.com/…: $\endgroup$ – Zack Riley Mar 25 '18 at 22:25
  • $\begingroup$ That's what I don't get. What do you mean by "photons acting as particles". They do just that in that paper. What is it that you would like to demonstrate? $\endgroup$ – garyp Mar 25 '18 at 22:29
  • $\begingroup$ in that paper they act like waves, which is why interference patterns are shown. I want to produce them as particles too. so i can see the 2 distinct segments chosen when fired at the two slits. $\endgroup$ – Zack Riley Mar 25 '18 at 22:30
  • $\begingroup$ If you're trying to do this with photons, you're out of luck. From the Wikipedia article: "Naive implementations of the textbook gedanken experiment [i.e. the particle-like pattern in the double-slit experiment] are not possible because photons cannot be detected without absorbing the photon." Usually this experiment is done with electrons, which can be observed without absorbing them. $\endgroup$ – probably_someone Mar 25 '18 at 23:22

Whether you are talking photons or subatomic particles, the knowledge I have is that you cannot observe both the particle nature and the wave nature at the same time. One of the fundamental principles of quantum mechanics is that the observer affects the event, i.e. "You get what you look for".

If you conduct the double slit experiment, you will get wave interference, meaning that you are observing the wave nature of light.

If you want to detect photons as particles, then you need to use a photon detector. Placing the photon counter behind the slits will not help you because the light behaves as a wave beyond the slits. You will not detect any 'photon events' through the photon detector.

In another futile effort, if you place the photon detector before the slits, the photon detector will detect photons but there will be no interference pattern beyond the slits. You have brought out the particle nature of the light.

More on the dual nature of 'quantic entities' here and here. The phenomenon of the effect of an observer on an event is explained here. These phenomena are among the reasons why we need quantum mechanics.

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    $\begingroup$ Thank you for your informational response, it was along the lines of what im looking for. I want to create the different states, at different times, with the option to switch the experiment to the other state. Could you perhaps elaborate a bit on the detectors, i am confident in my ability to produce a double-slit interference pattern and setup, I need to know more about how to make the detectors, and how they can be positioned/work without interfering with the photon its observing. if i am correct i change the detectors status (oberseve or not), in order to change the state? $\endgroup$ – Zack Riley Mar 26 '18 at 17:38

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