Two slit experiment at home and interference

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Discussion Overview

The discussion revolves around the feasibility of conducting the double-slit experiment at home and the nature of light interference patterns observed in such setups. Participants explore the conditions necessary for interference, the role of coherence, and methods to manipulate the wave patterns produced by lasers.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant questions the ability to observe wave patterns at home, suggesting that interference may be influenced by wavelength and the coherence of light sources.
  • Another participant explains that interference patterns are not visible with ordinary light due to the lack of coherence, emphasizing that lasers provide coherent light necessary for such experiments.
  • A participant seeks clarification on how to disturb the interference pattern while using a laser and two slits, expressing confusion about observing distinct light spots instead of a wave pattern.
  • One reply suggests that achieving the necessary which-path information without absorbing light is a challenge, indicating that this may require advanced equipment typically found in a college physics lab.
  • Another participant proposes a method of blocking one slit with a sharp edge to interfere with the wave pattern, although this is not the intended method of interference discussed.
  • There is a mention of the delayed choice experiment as a related concept, with a participant expressing skepticism about the feasibility of replicating such an experiment at home.
  • A later reply provides a link to a resource that may help demonstrate the effects of which-way information, although it clarifies that it is not specifically about the delayed choice experiment.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the manipulation of interference patterns and the conditions required for observing distinct outcomes. There is no consensus on the methods for achieving this at home, and multiple viewpoints on the feasibility and requirements remain present.

Contextual Notes

Participants highlight limitations related to the availability of appropriate detectors and the challenges of obtaining which-path information without affecting the light. The discussion also reflects uncertainty about the practical execution of advanced quantum experiments in a home setting.

jimmylegss
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Why is it possible to do this experiment at home and still see light as a wave? Isn't there loads of interference? Or does this have to do with wavelength? If you use a laserpen and 3 needles you can basically do it at home without shielding off anything...
 
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The reason is that those neat interference patterns can't be seen using any kind of light. The condition for interference to happen is that the two waves being interfered should be coherent. All of those other lights in the room don't satisfy this and so can't interfere in some way that disturbs your experiment. But two waves coming from a single point source, are indeed coherent. For extended sources, the source should be of special kind, which a laser is!
 
Im sorry, I did not phrase that very well.

I mean how can I observe and disturb that pattern? Since you can easily do this outside a vaccuum? basically I got a laser, shine it through 2 slits, and it shows a wave pattern. But how can i interfere and disturb that wave pattern and make them go through either one of the slits (and not see the wave pattern on the other side, just two blots of light).
 
jimmylegss said:
Im sorry, I did not phrase that very well.

I mean how can I observe and disturb that pattern? Since you can easily do this outside a vaccuum? basically I got a laser, shine it through 2 slits, and it shows a wave pattern. But how can i interfere and disturb that wave pattern and make them go through either one of the slits (and not see the wave pattern on the other side, just two blots of light).

You can't do that easily at home. The challenge is that you need detectors that will produce the necessary which-path information without absorbing the light (or you'll get no spot at all). Google around and you'll find some writeups of how it can be done with the resources of a (better than average) college physics lab.
 
jimmylegss said:
But how can i interfere and disturb that wave pattern and make them go through either one of the slits

Mount the slits firmly, then very carefully move a sharp edge like a razor blade behind them, so it blocks one of the slits.
 
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haha no i meant interfering with the wave pattern before it hits the screen with both slits open.
 
Last edited:

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