1. ### De Broglie Wavelength problem

I tried using lamba = h/p as follows: (6.626 * 10^-34 J *s) / (8 m.s * 0.6 kg) = 1.38041667*10^−34 and then using the small angle approximation sin(alpha) = lamba/d as follows: (1.38041667*10^−34)/(0.6m) = 2.30069444 * 10^−34 then converting to radians with the following: (2.30069444 *...

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3. ### B Detecting a photon passing through a slit without destroying it?

I cannot see how a photon can be detected and yet remain the same photon. I am thinking that the description "If a detector is place at each slit so that we know which slit the photon passsed through, the interefence patten does not form" is sloppy and in error.
4. ### I Double slit and detector

Suppose we have a double slit and we fire a photon through it with no photon detector at either slit. We get a interference pattern. Now we put a photon detector at the left slit. The interference pattern is destroyed, right? In this last setup, the photon can be located at the left slit. So...
5. ### I Double slit displaying anti-fringes?

The conventional Young double slit experiment displays the interference fringes with the first intensity maxima at the center of the detection screen ('center' means aligned with the center between two slits of equal aperture). These are simply called 'fringes'. However, I'm wondering if and how...
6. ### A The different interference patterns in the double-slit experiment

I've read on page 107 of the pdf http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=617AE275E5CECF5F0AFD69ACBC52141B?doi=10.1.1.205.6529&rep=rep1&type=pdf that . Thus it seems that there are three different interference patterns. 1: We do not try to detect the electron passing through the...
7. ### I Compound double slit with measurement on only one

This question relates to the double slit experiment where measurement affects whether an interference pattern is generated. If an experiment were performed where electrons were sent through a double slit with another double slit behind the first double slit, and the measurement device measured...
8. ### I Send the measurement device through a double slit

Hi. Double slit experiments are being performed successfully with increasingly large molecules. Some physicists (e.g. Anton Zeilinger) believe it might work with viruses as well. Assuming it works with a system that qualifies as a measurement device (be it a virus or something else complex...
9. ### I Use spacetime perturbance to figure out which way

Hi. Would it be possible (at least in principle) to use the spacetime perturbance caused by the energy-momentum of a photon (or any other particle) to figure out which way it took in a double slit experiment? Can this question even be answered in today's attempts at quantum gravity?
10. ### Double slit intensity question

Homework Statement Homework Equations (1) Φ = 2π*(dsinθ/λ) (2) Itotal = I0 cos2(Φ/2) (3) Itotal = I0 cos2(πdy/λR) λ = 585 * 10-9 m R = 0.700 m d = 0.320 * 10-3 m y = ? The Attempt at a Solution a) I used eqn (1) and divided the total oscillations by a complete oscillation to find the...
11. ### B Why doesn't the plate interact with the particle in double slit?

When particles are shot at the plate/screen in the double slit experiment, why doesn't the particles interact with the screen? Shouldn't the plate act as an observer and "collapse" the wave function into one or the other slit? Why does it take a measuring apparatus to know which slit the...
12. ### Double Slit Wave Interference - what is m?

Hi, I'm doing a very simple problem, but I don't understand the diagram provided (see image below). What is m here? I know that m is the order with respect to the central bright fringe, but there isn't a central bright fringe (assuming those circles are the bright fringes)? Homework...
13. ### I Delayed Choice with both slits closed, What happens?

I am reading about this most famous experiment in physics, the double-slit experiment. My question is very simple: in the "Delayed Choice" version, have they done the test where they close BOTH SLITS (at once) after the photon has passed the slits?? If so, what have been the result? Can you...
14. ### B The Conscious Observer

How exactly does the mere act of observing collapse the wave function of, say, photons? I don't quite understand that one. And Richard Feynman's question related to Young's double slit experiment and the fact the electron went through both slits, as well as neither, and just one slit, and just...
15. ### A Decoherence in the double slit experiment

I have two questions about the following type of scenario: We have a laser sending photons through the usual double slit apparatus giving us the usual interference pattern, except that now we introduce some physical matter (that are not photons) that the photons will interact with before going...
16. E

### Interference Pattern problem

1. The problem statement, all variables, and given/known data The problem is attached. Homework Equations I do not know any relevant equations to this matter but I believe that a maximum has the length of λ and a minimum has the length of λ/2. The Attempt at a Solution I see one maximum and...
17. R

### B Double slit question

Apologies if this is a ridiculous question (I have zero scientific education). I recently watch a video about retrocausality and thought that this may be an explanation for the wave properties of a single photon fired in the double slit experiment. My scientific ignorance will be on full show...
18. ### I Interference of a single photon in an interferometer

I think we can all agree that when we are shooting many photons one by one, through an interferometer, we can eventually land up with the interference pattern. This can be explained by saying that two photons combining in some areas to give four photons and in some places annihilating each...
19. ### B Double Slit Experiment: Timing & Reflection Interference

Dear All, I have a couple questions on the double slit experiment I hope you can help shed some light (or photons) on. =) Arrival Timing of Photons In a normal double-slit experiment like the above setup, do photons always arrive at the detector at a constant speed (basically, speed of light)...
20. ### B Double slit probability question

Consider the double slit experiment; if we position a detector at, say, the left slit, will a single particle, say, an electron, when fired at the slits, always be detected at the left slit, or will it be detected at the left slit 50% of the time? (so that it is 50% of the time at the right slit)
21. ### B Basic question about double slit interferance

I am new here so I will start with a warming up question :) My question is very trivial here we go: In double slit experiment when shooting one photon at a time, we get interference pattern. Then when we put a sensor at one of the slits the interference pattern disappears because we now know...
22. ### B Interference pattern after a particle is detected?

Say we have a particle, like an electron in a double slit experiment. And say that we have a measuring apparatus to detect it right after its fired out of the electron gun. And after that it goes through the double slit and hits the detector plate. Would we see an interference pattern? If the...
23. ### I How does MWI deal with the destruction of interference?

How does MWI deal with the destruction of interference in the double slit experiment when a detector is placed at the slits? Since the wave function never collapses, and the universe doesn't actually split in MWI, how does the interference go away? Does the measuring device at the slits reshape...
24. ### I Relativity's "time dilation" or clock accuracy alteration

i've seen the double slit experiment and the delayed choice . my mind rejected the conclusion, but the experiment setting and configuration of delayed choice is rational and holds water so i accepted the experiment outcome even if it means the world isn't real. i had to give that intro that...
25. ### B Does the Uncertainty Principle work through barriers?

I'm currently designing an experiment on Double slits for a high school science fair, but I'm not sure whether it's plausible or not. I'll be spending some of my savings for this, that's why I would like to hear some feedback from more-knowledgeable people first. In this experiment, I am trying...
26. ### B Double Slit detectors question

My question about the double slit experiment is this: why is it that nobody suspects that the detectors used to detect particles as they pass through the slits in the double slit experiment aren't causing some interference with the experiment which makes it seem as though they are acting like...
27. ### A Double slit construction

How are the double slits constructed? If you use electrons or photons then they should interact with that material or what?
28. ### Double Slit: Separation and Path Length

Homework Statement A double slit apparatus is held 1.2 m from a screen. (a) When red light (λ = 600 nm) is sent through the double slit, the interference pattern on the screen shows a distance of 12.5 cm between the first and tenth dark fringes. What is the separation of the slits? (b) What...
29. ### I Quantum tunneling questions

Hello guys, I have few questions about the well-known quantum tunneling. I'll start off with the animation from wikipedia So question #1 why doesn't the barrier collapse the wave function, is that even possible? What's the difference between the barrier and the measurement screen in double...
30. ### B Entangled photons thought experiment

Following scenario: One million entangled photon pairs are created and are sent to Alice's and Bob's laboratory such that Alice receives 1 million photons(or any other large number) of which each is entangled to one of the million photons Bob receives, their laboratories being at a distance to...