Questions about the Double Slit Experiment

Click For Summary

Discussion Overview

The discussion revolves around the double slit experiment in quantum mechanics, exploring the implications of observing particle behavior and the effects of knowledge on interference patterns. Participants consider various scenarios involving observation and the potential outcomes of the experiment.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions what happens if the double slit experiment is conducted while recording which particles go through which slit, and whether looking at the results affects the observed pattern on the wall.
  • Another participant asserts that the interference pattern remains unchanged by the act of looking at the data, emphasizing that it is the modification of the experiment to record "which way" information that alters the interference pattern.
  • A third participant notes that interpretations of the double slit experiment vary based on different theoretical frameworks, such as Copenhagen or Bohmian interpretations, and expresses frustration over the inability to discuss their validity.
  • One participant argues that all interpretations agree that if which-slit information is leaked into the environment, the interference pattern will be lost, regardless of who observes the information or when.

Areas of Agreement / Disagreement

Participants express differing views on the effects of observation on the interference pattern, with some asserting that the act of looking does not change the pattern, while others emphasize the importance of how the experiment is modified. There is no consensus on the implications of knowledge and observation in the context of the double slit experiment.

Contextual Notes

Participants reference various interpretations of quantum mechanics, highlighting the complexity and nuances involved in understanding the double slit experiment. The discussion reflects a range of assumptions about the nature of observation and its impact on quantum behavior.

andrewshen123
Messages
1
Reaction score
0
As I'm not learning quantum mechanics formally in a classroom, I have no real experience with the matter, or a teacher to whom I can pose my questions. There are a few experiments I'd like to run as well, but no way to do so. In any case, I'm hoping that someone else has run these experiments, or at least has theories as to what will happen.

  1. What happens if you run the double slit experiment, recording which particles go through which slit, look at the back wall before looking at the results of the observations, then look back at the wall? Will it start off as an interference pattern, then become a clumping pattern, since your knowledge about the particles has changed? Will it "predict" that you will look at the data, and start off as a clumping pattern? Will the fact that you've already looked at the wall lock the particles in place, so even after you look at the data, their positions won't change because you know where they landed? Or something completely different?
  2. What happens if you run the experiment with two (groups of) people, one to look at the wall and one who may or may not look at the data. Will the results always agree with each other? Does it matter if you look at the wall or the data first, even if it's two different people doing so?

Thank you for reading, and hopefully for responding.
 
Last edited:
Physics news on Phys.org
The interference pattern doesn't change just because someone chooses to look or not look at the data about which slit the particles passed through. Modifying the experiment in order to record the "which way" information is what changes the interference pattern--whether or not anyone looks at that information.
 
"double slit experiment" interpretations depend on "school" you are belong to.
There are Copenhagen, Einstein, Bohmian,... or your own.
Physics Forum rules forbid even discussion of the validity of any of them :(((((
So i must close my mouth.
 
Don't all the interpretations agree that, as long as you modify the experiment in such a way that which-slit info is leaked out into the environment, you will not get the interference pattern. Shouldn't matter if or when or who looks at the which slit information, just that the which slit information is available is enough to remove the interference.
 

Similar threads

Undergrad Which-Path from Global Momentum Measurement in Double Slit
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Single vs. Double slit coherence clarification please
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Does a qubit break interference in the double slit experiment?
  • · Replies 10 ·
Replies
10
Views
2K
High School Yet another double slit thought experiment...
  • · Replies 20 ·
Replies
20
Views
2K
High School Double-slit experiment and time
  • · Replies 24 ·
Replies
24
Views
3K
Undergrad Double Slit Experiment: Measurement versus Observation
  • · Replies 3 ·
Replies
3
Views
2K
High School Double Double Slit Experiment -- Question about Variations
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Double slit experiment with observer
  • · Replies 14 ·
Replies
14
Views
4K
Undergrad Double-slit experiment, determining which slit an electron passed thru
  • · Replies 26 ·
Replies
26
Views
3K
Undergrad Why doesn't gravity cause double-slit decoherence?
  • · Replies 11 ·
Replies
11
Views
2K