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3answers
212 views

How to observe a particle with indefinite position?

As I understand it, when physicists talk about something behaving both like a particle and a wave, what they mean is that it has momentum like a particle, but its position is determined ...
2
votes
1answer
138 views

Deducing from the double slit experiment that electrons mostly behave like particles

I saw this video of a lecture by Feynman where he said that electrons behave like particles when there is a photon source to detect which slit they pass through. Does this imply that electrons mostly ...
2
votes
2answers
348 views

What is the relationship between distinguishability and probability in Quantum mechanics?

Firstly I am sorry for any awkward English expressions. Recently I'm reading "Feynman Lectures on Physics - Quantum Mechanics" and come to have a single question. In the book Feynman explains, "You ...
3
votes
1answer
111 views

How would a semi-classical particle react to the double slit experiment?

As far as I know, there is a smooth transition between quantum and classical regimes, so that even classical particle like a massive object has a wavefunction associated with it. However, the double ...
3
votes
2answers
366 views

What happens in this revised double-slit experiment?

Put the classical electron-emitting double-slit apparatus in a sealed box. At each slit there's a counter to check whether an electron has passed it or not, so had the apparatus been left in open, we ...
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1answer
2k views

what is phase angle of wave function $\phi \,$?

this is wave function: $$\Psi{(\vec r, t)}=\Psi_0 e^{i(\vec k \cdot \vec r-\omega t)}$$ $$\Psi{(\vec r, t)}=A e^{i(\phi + \vec k \cdot \vec r-\omega t)}$$. what is phase angle $\phi$ of wave ...
0
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1answer
427 views

How does the Fraunhofer irradiance distribution look for a double slit aperture of different lengths?

How does the Fraunhofer irradiance distribution look for a double slit aperture with $d$ = integer multiples of $b$?
2
votes
1answer
62 views

Does classical physics predict the effects of shining a laser at a hair?

The discussion on this webpage mentions that shining a laser beam at a hair produces an effect like that of the double-slit experiment. Does classical physics predict the effect you observe when you ...
1
vote
1answer
516 views

How Light or Water Intensity is equal to square modulus of wave function of Light or Water Waves $I=|\psi|^2 \,$?

I've seen the Wave Function as a psi $\Psi$ $\psi$. And always heard that the wave function is the Complex Number as Imaginary and real number. But I've never seen it I've never seen components of ...
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3answers
2k views

The Double Slit Experiment and the changing of electron behaviour

As you will all know, when one tries to detect which slit an electron has gone through with close up observation, it changes from behaving like a wave and producing an interference pattern to behaving ...
4
votes
4answers
234 views

Slit screen and wave-particle duality

In a double-slit experiment, interference patterns are shown when light passes through the slits and illuminate the screen. So the question is, if one shoots a single photon, does the screen show ...
3
votes
1answer
191 views

Can spatial coherence be maintained in fiber optic cables over time?

I am doing research with a double slit experiment, using a beam splitter and 2 lengths of fiber optic cable, whose ends brought close together form the effective double slit. I notice that the ...
5
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1answer
272 views

How does the Double Slit Experiment work in detail?

What is the best detailed description/visualisation of the experiment available? Describing what is actually measured, how the data is analysed, correlated and interpreted when for example large ...
3
votes
2answers
287 views

Decoherence when no one is looking?

I understand that in the single-electron-at-a-time double slit experiment, if a detector is placed before the slit, the interference pattern vanishes. Suppose I left the detector on, but put a bag ...
1
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4answers
693 views

Questions on wave-particle duality

Wave-particle duality states that a particle has both wave properties and particle properties when one is not observing it. 1) What is an observer? Need it be anything living or can other particles ...
2
votes
4answers
298 views

Double slit experiment and indirect measurements

In the classic Young double slit experiment, with slits labeled as "A" and "B" and the detector screen "C", we put a detector with 100% accuracy (no particle can pass through the slit without the ...
4
votes
4answers
1k views

Young's double-slit experiment with detectors

Related: Accuracy of various optical instruments In many books, it's written that knowing which slit a photon passes through (by placing a detector before the slit) in a Young's double-slit setup ...
5
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2answers
294 views

Accuracy of various optical instruments

I understand that this may not be the type of question allowed here, but I'm not sure. Feel free to close this if you feel that it shouldn't be here I'm planning on carrying out a certain set of ...
3
votes
2answers
426 views

Entanglement and the double slit experiment

Is the double slit experiment an example of entanglement when it seems as if the photon is going through both slits? Or put another way, is it at this stage when we attempt measurement we see a photon ...
4
votes
2answers
832 views

Double-slit experiment simulated with water waves?

We all know the explanation videos and other material using the water waves analogy to illustrate the propagation of electrons or photons and the interference patterns measured in the the single-slit ...
5
votes
1answer
171 views

Gauge invariance and Bohm-Aharonov effect

I am confused with the Bohm-Aharonov effect: though quantum mechanics is said to be gauge invariant, the presence of a solenoid imposes a gauge. I used to think that a phase shift did not change ...
2
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0answers
240 views

In Scully and Druhl delayed choice quantum eraser experiment, are there limits to the lengths of the delay?

I'm in humanities, not physics, so please bear with me. I am trying to understand this experiment and have a few unanswered questions. I have read the other posts on this site that discuss the ...
3
votes
2answers
134 views

In the dual-slit experiment, can the time it takes for a photon to arrive reveal the path it took?

It seems like this experiment is possible: Fire a photon, and start a timer The photon travels through the slit(s) The photon strikes a plate -- the timer is stopped. Based on where on the plate ...
1
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1answer
116 views

What kind of interactions denote 'observation'?

I'm quite perplexed by the notion of 'observation' in regards to the collapse of a particle's probability wave. Does a particle's wave only collapse when it is involved in a strong interaction (such ...
3
votes
6answers
430 views

Do we really know which slit the photon passed through in Afshar's experiment?

The plain old double slit experiment displays interference when we don't measure which slit the photon passed through, and no interference when it is measured. Let's turn our attention to the case ...
6
votes
4answers
952 views

Variation of delayed choice quantum eraser

Let me base the discussion on the pictorial description of the delayed choice quantum eraser experiment on wikipedia. First suppose that we do precisely the same thing with the lower parts of the ...
6
votes
9answers
1k views

What exactly is the 'observer' in physics and/or quantum mechanics? [duplicate]

Possible Duplicate: nature of an observer For instance, in the double slit experiment, what is exactly defined as an observer? I remember from somewhere, light is also an observer?
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6answers
3k views

Hidden observers in Double Slit experiments - Do they matter?

I'm still struggling a bit with some ideas around double slit experiments. One that keeps cropping up for me is the role of observers. Imagine a classic double slit experiment with a hidden observer ...
9
votes
1answer
1k views

What are the specific requirements for a do-it-yourself quantum double-slit experiment?

I was shocked to recently learn that the double-slit experiment is not only possible to do with completely ordinary equipment (with photons of course), but it actually looks rather easy. This is from ...
2
votes
2answers
1k views

Electron behavior changes when observed?

I saw this video of the double slit experiment by Dr. Quantum on youtube. Later in the video he says, the behavior of the electrons changes to produce double bars effect as if it knows that it is ...
2
votes
1answer
293 views

Quantum phenomena near black hole event horizon

I wanted to re-open the question of quantum measurements across event horizons. If I set up two slits or more generally a diffraction grating which crosses a black hole event horizon, and I shoot a ...
4
votes
1answer
241 views

Young's double slit

Am I right to think the (general) probability distribution of photon in a double slit experiment at the screen has the form $|\psi|^2 = c e^{\alpha x^2}\cos^2(\beta x)$? (Due to the superposition of ...
2
votes
3answers
2k views

Why is the central maximum the brightest?

This is a question directly from a homework sheet, however I can't find any decent answers online so hopefully someone can help! In single slit diffraction, why is the central maximum double the ...
1
vote
3answers
413 views

'Observer in double slit experiment' publications available?

I've just found Dr Quantum video sample where double split experiment is presented conducted out by researchers. Are there any papers published in peer reviewed journals on that experiment to read in ...
3
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3answers
540 views

Defining Measurement in Quantum Mechanics

I should begin by saying that I am a total newbie when it comes to Quantum Mechanics. Therefore my question might sound metaphysical to people who know their stuff. So please forgive. What I am ...
5
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1answer
669 views

Double slit experiment - how to see an electron going through a slit?

This is my first question here. Hope it not too dull to you guys :p I found this video on youtube. After 3:24 it says if there is an observer detecting which slit the electron goes through, there ...
0
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3answers
422 views

Quantum Mechanics

Quantum Mechanics. Could anyone help me to understand the concept involved? Double slit experiment can be easily understood by Wave nature of light, but while explaining it with photons, it required ...
1
vote
1answer
335 views

Double-slit experiment with alternating on-off switch

Suppose we perform a double-slit experiment with a detector placed at a position of minimum intensity (maximum destructive interference), off-center where the path lengths differ by half a wavelength. ...
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3answers
388 views

Is it possible to define a “it went through two slits” observable?

This concerns the famous two-slit experiment. Electrons or photons or your favorite particle, doesn't matter. As we all know, the attempt to detect which slit the quanta pass through leads to loss ...
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vote
2answers
243 views

Double slit experiment and perforated walls' properties

I have a doubt about how double slit experiment is made. Let's think about the perforated wall, what are the requirement for it? Can a photographic plate could be used as a wall ? I see a problem ...
1
vote
2answers
304 views

What's inside the slit in double slit experiment?

If double slit experiment is done in a environment with air, then slits could also contain air made up of (approx. 80% nitrogen, 20% oxygen), then there is not empty space inside the slit. How can it ...
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6answers
1k views

How is the double slit experiment modeled in contemporary physical theories?

Suppose I have the following double split experiment set up: a monochromatic electron source of low intensity, which we can model as emitting a single electron at a time with energy $T$. a ...
5
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4answers
594 views

Two slit experiment: Where does the energy go?

In Physics class we were doing the two slit experiment with a helium-neon red laser. We used this to work out the wavelength of the laser light to a high degree of accuracy. On the piece of paper the ...
5
votes
1answer
363 views

How to mathematically formulate the Two Slit Experiment in Special Relativity?

How to mathematically formulate the Two Slit Experiment in a Lorentz invariant framework. Is there a paper about this?
6
votes
2answers
426 views

Is Time Significant in the Double Slit Experiment

When doing the classic double slit experiment is the time between emitting photons significant at all? Say, a single photon is emitted, the scientist waits T seconds, then emits another photon. Are ...
7
votes
2answers
556 views

How do electrons interact if one of them had just exited the two slits of the double-slit experiment?

Consider the following experiment: a double-slit set-up for firing electrons one at a time. Let's now add a second electron (orange), which is fired parallel to the first one, but in the opposite ...
11
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5answers
845 views

Double slit experiment near event horizon

What happens if you perform a double slit experiment near an event horizon, if one of the slits is outside, one is inside the event horizon?
12
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6answers
693 views

Particle wavefunction and gravity

Suppose a particle has 50% probability of being at location $A$, and 50% probability being at location $B$ (see double slit experiment). According to QM the particle is at both $A$ and $B$ at the same ...
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votes
4answers
4k views

Is Dr Quantum's Double Slit Experiment video scientifically accurate?

I'm fascinated by the fundamental questions raised by the Double Slit Experiment at the quantum level. I found this "Dr Quantum" video clip which seems like a great explanation. But is it ...