Choice Definition and 693 Threads

I heard many people saying that the delayed choice experiment means that future events can affect the past. I doubt it as I believe that the wavefunction of the particle collapses as soon as a measurement is made. It does not matter where the detector is placed. As long as there is a detector...

For someone who kinda likes all stems in general,this process of applying to the right course is very,ver messy.There's no place in internet (that I found) with a clear explanation of what each course gets you in terms of career and from which courses those careers get people To be concise...

Hello! Does anyone here have raw data from a delayed choice quantum eraser experiment that you wouldn't mind sharing? Ideally, data from all the detectors, not just coincidence counts that the analysis usually focuses on? Or, are you aware of any data repository where data from quantum physics...

In Delayed choice quantum eraser experiment (https://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser) entangled photons are sent on different paths. They reach their detectors at different times. The one arriving early is called a signal photon. The photon that arrives at its destination at...

Googling for some unrelated topic, I stumbled upon Quantum Mechanics in an Evolving Hilbert Space. A lot of the math in this paper is beyond my present level, but some of the more descriptive passages made intuitive sense to me. Based on this, my question is, is the formalism of an evolving...

As almost everybody knows, DCQE experiment only shows interference after the data analysis, never in the first instance, regardless of future events for idler photons. https://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser So, my question is, why you cannot see interference with this...

Hi all, I study Mathematics and Theoretical Physics at university. Next year, I'll have a choice between three modules; Thermodynamics and Statistical Physics Cosmology Fluid Mechanics My main interest is Condensed Matter Physics; therefore, thermodynamics and statistical physics is a given...

Consider the following facts: 1. For a particle with momentum ##k##, the two transverse polarization vectors ##\epsilon({\bf k}, \lambda_{1})## and ##\epsilon({\bf k}, \lambda_{1})## are purely spatial and orthogonal to ##\bf k##, that is, ##\epsilon^{0}({\bf k}, \lambda_{1}) = 0,##...

Did I make the right choice? I dropped my Physics course which was equivalent to PHY211 at Penn State. I dropped it because I had never taken a physics course in high school. I did a poor choice when scheduling my class for spring 2017. My college currently teaches General Physics 1 (algebra...

Homework Statement A circus cat has been trained to leap off a 12 m high platform and land on a pillow. The cat leaps off at v_0 = 3.5 m/s at an angle of 25 degrees. Where should the trainer place the pillow so that the cat lands safely? What is the cats velocity as she lands on the pillow...

Homework Statement A vacuum photodiode detector utilizes the photoelectric effect to detect light. The photoelectric effect causes electrons to be ejected from a metal plate when photons of light are absorbed by the metal. The energy of a photon is given by the equation E = hf, where h = 6.6 x...

Homework Statement A hydroelectric power plant is built next to a reservoir with a water turbine beneath a dam. In normal operation, which of the following conditions will increase the flow rate of water, in kg s^-1 ,through the turbine. (1) There are too much water in the reservoir. (2) After...

Hi. The Wikipedia article on the delayed choice quantum eraser is mostly about Kim's experiment where there's IMHO not really a 'choice' about the erasure of the path information, at least not by the experimentators. Have such experiments also been performed where this choice is more...

Would you please introduce me some textbooks that offer multiple choice or true-false questions at the end of each chapter so I can practice before my final exam? Basically, that class I am taking right now cover many central topics in Undergraduate Probability course such as: • Moments and...

I've been thinking about a communication system that could allow faster than light communication. The basic principle that would make this system work come from the double-slit experiment and Wheleer's delayed choice experiment, taking advantage of the different patterns that would appear on a...

This delayed choice quantum eraser experiment captured my attention and after deep thought about it, I find it really startling and totally punishing to my common sense. My question is: Can you predict the future, say, a human's mind, using the quantum eraser? I imagine a modified version of the...

I know that clarifications about delayed choice experiment was asked million times, and I understand the idea, but I was not able to find the discussion of this particular situation anywhere, though I tried hard. This setup is described in Brian Greene's Fabric of the Cosmos book (note my...

Let me introduce myself. I am a new graduate in mechanical engineering, with almost 2 years of co-op experience. I have been applying jobs for 2 months and had couple of phone interviews and one regular interview. To be honest, Canadian job market is not doing well for the new graduates and...

Idk if this is the forum to turn to or even if its the correct forum thread thingy. In that case i apologize in advance. I got no where else to turn to, and I really have hoped to gain some answers somewhere. I have a lot of problems with physics. I'm starting to only now get A's in most of my...

This is a proposed idea. Using the "Delayed choice" version of the double slit experiment, can you devise a way to send Information (in this case the winning lotto numbers) Into the past? I imagine that one could convert the winning numbers into binary, assigning a 1 for wave experiments, and 0...

Hello, friends! My textbook, Gettys's Physics, says that the Lorenz gauge choice uses the magnetic vector potential $$\mathbf{A}(\mathbf{x},t):=\frac{\mu_0}{4\pi}\int \frac{\mathbf{J}(\mathbf{y},t-c^{-1}\|\mathbf{x}-\mathbf{y}\|)}{\|\mathbf{x}-\mathbf{y}\|}d^3y $$and the electric potential...

Homework Statement The Force applied to an object is equal its mass times its acceleration Assume that the ball has a mass of 40g. What is the force due to gravity acting on the ball? Homework Equations F=ma The Attempt at a Solution F=(.04)(-9.81) I get a negative answer, does that mean...

Homework Statement Why does PET scanner use positron emitters? 1-positrons have more penetrating power than electrons 2-positron emitting isotopes are cheap and widely available 3-the location of emission can be located better because a pair of gamma rays get emitted from the body...

Homework Statement E is the "right answer" Homework Equations B around a long wire = mu * I / [2 * pi * r] The Attempt at a SolutionOK. I know that the magnetic field lines will travel in a clockwise direction around the wire from the viewer's orientation with the current going away from...

Hey, I was watching this video About the quantum eraser experiment (I suggest you watch too, so we would be speaking in the same terms). As I understand it, The experiment goes such that: first the photon enters through the slits as a superposition, then the photon gets measured to gain...

Hi, my supervisor has asked me to decide upon a suitable topic for research work in my thesis-based Masters. I have checked out his recent papers, and I find that I am interested in research topics that he used to work on 6 or 7 years ago, but does not work on anymore. Is it alright to ask him...

Hello. This topic seems to be discussed a lot of times before. But I still have some questions which was not clarified earlier and I will be grateful if someone will give me explanations :) First of all, to define a context, original experiment setup: (source...

What if our quantum eraser was a black hole? There's talk of event horizons preserving all the information that crosses them? Could we test this hypothesis by seeing whether or not black holes make good quantum erasers? Depending on the distance to the black hole - it might be hundreds...

Greetings. I've come with yet another issue which is causing me some distress. So I took everyone's advice and started self-teaching calculus (or at least I started trying... Limits are still confusing). However, my problem doesn't stem there. I decided to review my algebra before year 10...

So i am 18 years old , and i just graduated high school with a high score . recently i got accepted into medical school and my parents are pushing me hard to study there . aside from school work , i have been extremely interested in technology , i did some extensive research on programming...

I've been reading Brian Greene's "The Fabric of the Cosmos" and am currently at the description of the delayed choice quantum eraser experiment. My understanding is that this can be set up so that the idler photons can be measured (long) after the signal photons hit the detector screen. Under...

Is it possible that the reason the delayed choice two slit experiment outcomes occur is because for the photon, traveling at the speed of light, the past, present and future are all as one, and therefore it "knows" what is going to happen and therefore always "makes the right choice" at the...

Hi I have some questions and ideas regarding Bohr's double slit experiment which he extended with a Camera as an illustration of delayed choice. I read about it 40 years ago but can't find a reference to it, I'm hoping it wasn't apocryphal but it's consistent with Q-phys as I know it. The...

I have seen many times mention of measuring the 'speed' of state-change over quantum entanglement, and potentially measuring it. re: wave/particle 'duality' this paper explains everything extremely clearly and dispels such popular notions from my mind for a single particle...

I made some tweaks to the diagram you may have seen me post in threads about delayed erasure. Let me know what you think, what's confusing, etc. Here's the updated version: And the old version:

Double-slit experiments have been done to death, Obtaining and preserving which-path information (or otherwise) for a particle or photon causes its entangled partner to show the probability distribution with or without the interference pattern, violating Bell's inequality and thus proving...

Hi! I already posted something here, but I think there's no problem in asking something different yet a bit related with my previous post. In the future, I see myself starting a company of electrical motors and generators. I want to master the designing and the technology used in order to build...

Homework Statement PQRS is a square. Three point charges -Q, +Q and -3Q are fixed at P, Q and S respectively as shown. A point charge q is then placed at R and it experiences a net electric force towards S. Which of the following is equal to q? photo ...

Homework Statement The turns ratio of a transformer is 20:1 step down and the primary coil is connected to a 220V a.c. supply. If the secondary coil is connected to a '36W, 15V' light bulb and the efficiency of the transformer is 80%,find the current in the primary coil. Homework Equations...

Are there certain events that must inevitably occur in all of the possible branches the wave function could split into? For example, if a black hole forms in our ''branch,'' what other possibility is there for that collapsing configuration of matter other than to turn into a black hole? Unless...

Hi! :) I have this question regarding delayed choice quantum eraser - If my understanding is correct then interference pattern will form/not form based on whether there is erasing mirror in path of entangled particle - regardless of time when particle arrive at mirror. Should not it be...

I just came across the delayed choice quantum eraser experiments (kim et al 1999) through Wheeler's astronomical delayed choice thought experiment and I can't stop thinking about it :-( I would like to get some ideas on how people interpret this, either the general physics community consensus...

1. The equation below represents the reaction of chlorine with hot concentrated potassium hydroxide solution: 3Cl2(g) + 6KOH(aq) → 5KCl(aq) + KClO3(aq) + 3H2O(l) Which of the following statements concerning this reaction is/are correct? (1) Potassium hydroxide acts as a reducing agent (2)...

I'm a sophomore in college studying physics and computer science, and I'm in the process of considering a transfer. I have offers to Brown and Northwestern, and I'd like to get some more opinions on the quality of each school for these fields. I currently attend Vanderbilt. In physics, beyond...

Homework Statement Homework Equations sum of torques = 0 The Attempt at a Solution So I tried to put the torques into the equation: Sum torques = mgL - T *sin(theta) * (L-x) = 0. Solving for the T gave me [mgL]/[ (L-x) * sin(theta) ]. This is not an option in the answers. Could anyone...

As an international student who has recently completed high school, I now need to decide what college I will go to. Since "Cambridge, duh" gets a bit irritating after one has heard it a thousand times, I decided to write up a little list of the pros and cons I associate with each of the two...

I think cosmologists use a poor choice of words when they say the universe is expanding. I don't dispute any of the science behind the "expanding" universe but I do want to dispute the appropriateness of the phrase to the science. I think people typically understand expanding to mean: getting...

Inspired by Micro's thread a couple of weeks ago, you get to pick three of the following mundane super powers! Post your preferences, extra points to those who find good combinations: Super bilingualism. Pick any language in the world, learning that language is now extremely easy for you...

Homework Statement The cell in the circuit has an emf of 2.0 V. When the variable resistor has a resistance of 4.0 Ω, the potential difference (pd) across the terminals of the cell is 1.0 V. What is the pd across the terminals of the cell when the resistance of the variable resistor is 12...

Would you be able to provide an assessment of the high energy/string theory theoretical physics ranking of the four programs below: Graduate program in University of Florida Graduate program in University of Alberta Graduate program in UC Davis ICTP Postgraduate Diploma (High Energy, Cosmology...