Choice Definition and 667 Threads

Hi, I would like to ask some questions regarding "delayed choice quantum eraser experiment". (I think it is possible for those who are familiar with this experiment to skip the text and go ahead into questions 1 and 2.) It is mentioned e.g. on these links...

Homework Statement a piece of metal of 10cm X 20 cm X 5 cm is sitting flat on the bottom of water basket, with one of the 10cm X 20cm sides facing up. the metal has density of 19.3 g/cm3. The basket is filled with water(full). The backet has a radius of 0.25m and a hight of 1m, density of...

What are the best books to use for preparing for the Physics Olympiad? I have University Physics and Fundamentals of Physics? Which one is better? Thank you!

Just a quick question regarding the sources used for investigating entanglement (of photons). There are two types of production method as I understand it: ('Fundamentals of quantum optics and quantum information', Peter Lambropoulos, David Petrosyan, 2006, Springer): Page 242 "In fact...

Another seemingly simple issue that I've never really had to think about before until now. Say, I have to filter out a solid precipitate that I see in a limited amount of unknown solvent. I have a Büchner funnel, but I need to have a solvent to rinse the solid with. Questions I have...

Hi guys, Well I now have a few weeks to make up my mind in which to put as my first choice (not sure if I have a second but even if I did it would be sort of irrelevant as all offers are AAA or AAB :D). I've basically numbered it down to Manchester and Nottingham, I had offers from both York...

Learning device, help me expound: on Faraday's choice of "ion", and "unionized" So I was writing down some notes to myself on electrochemistry (100 level college chemistry---elementary electrochemistry chapter) and I wrote down the word "unionized" (as in, 'un-ionized') and realized that there...

1. A ball rolls of the edge of a horizontal roof at 10.0m/s. Two seconds later the speed of the ball will be... a)9.80 b)10.0 c)19.6 d)29.6 e)none 2. Two forces of 10 N each act on an object. the angle between the forces is 120degrees. the magnitude of the resultant force on the object...

I'm terribly sorry if this has been asked before, but at the moment I want to work in Nuclear Fusion eventually, MCF like JET etc. seems the most interesting although ICF like NIF is pretty interesting too.. However, many people change their mind over what they want to study whilst they are...

hi, I am writing a computer algorithm which descibes the change of choice. 1.your friend puts $10 in a box among three (there are three boxes) but you don't know which. 2.you choose one of them but do not open it. 3.your friend opens (eliminates) one of empty boxes i.e. if you choose...

we all know that coal fired plants are becoming more and more unpopular with people and know we are looking towards renewable sources of energy like solar and wind and also nuclear energy. but in the near/distant future when the changes do occur, how will these changes affect our lives??

I really enjoy physics and I've always (well maybe not always) wanted to become a physicist but i kind of changed my mind because they don't get paid a whole lot. Then, I wanted to become a rocket scientists because i still get to study physics along with mathematics and engineering. Also most...

I am just starting to learn about attitude estimation and control of a flying(or actually, a freefalling) vehicle. There will be inputs from accelerometers and gyroscopes, Kalman filtering to estimate the correct attitude and control algorithm to achieve the desired attitude. I am still...

Homework Statement Charge is distributed uniformly on the surface of a large flat plate. The electric field 2cm from the plate is 30 N/C. The electric field 4cm from the plate is: A. 120 N/C B. 80 N/C C. 30 N/C D. 15 N/C E. 7.5 N/CHomework Equations E=kq/r^2 (possibly) The Attempt at a...

Consider Gauss's law: \oint \vec{E}\cdot d\vec{a} =\frac{Q_{enc}}{\epsilon_0} . Which of the following is true? A. E Must be the electric field due to the enclosed charge B. If q=0 then E=0 everywhere on the Gaussian surface C. If the charge inside consists of an electric dipole, then the...

Homework Statement 1.Reflection goes with a. longitudnal wave b.trasnsverse wave c. both d.neither 2. if mass of teh bob on a springs are increased, howe whould that affet the period of the vibrations? 3. if a spring is released fr. progressively larger displacments, how owould this...

My son (act 31) is having trouble choosing his mechanical engineering college. He has been accepted by Michigan State at Ann Arbor (and offered a scholastic scholarship of $6000 + international study scholarship of $5000), Rose Hulman, and expects to be accepted by Purdue. (He has not applied...

I'm a very thickheaded layperson so be warned, I'll probably require a lot of patience. Anyway, I'm having a very difficult time understanding the delayed choice quantum eraser experiments. It seems to me that it is implying that either the idler photon is going back in time and changing the...

Does anyone have a link or multiple choice questions for old AP physics B or C?

I'm sure there's been a lot of posts on this before, but even after taking a look at some of them, this experiment is still eluding my understanding. I'm aware that there's no backwards causation--and that the eraser causes interference by random 'categorization'--but I'm nonetheless...

Hi there, I textbook it said the zero potential level can be chosed arbitrarily. Let's take the gravity as example, if an box is moving from the top of a incline to the bottom without considering the friction, suppose the center of mass located in the geometric center of the box. Someone pick...

1. Which rolls to the bottom of a hill sooner, a car tire alone or the same tire mounted on a rim? a. The mounted tire, provided the tire is more massive than the rim b. The tire alone, provided it is as heavy as the rim c. The mounted tire, provided the tire is as heavy as the rim d. The...

Homework Statement Which of the following is a correct statement about gravitational force? A. It is applicable only to our solar system. B. It is both an attractive and repulsive force. C. It is directly proportional to the product of the masses involved. D. It is directly proportional to...

I have read that these experiments have been successful and do not cause a disagreement with QM. But I can’t quite determine what was learned. So what did they prove or disprove? Is there a simple explanation? I thought they were designed to determine if wave collapse breaks either locality or...

Delayed Choice Revisited. Here is a very cut down summary of Wheeler's delayed choice experiment (hope I got it essentially correct): When a wave packet is half way between the screen and the double slits, a decision is made by the observer as to whether to look for a photon or a wave...

I bolded the answer I think is correct - I'm just a little unsure on these, any help would be appreciated! 1. A capacitor and resistor are connected in a series with a batter and a switch. The instant after the switch is closed A. the voltage across the resistor is equal to the emf of the...

Homework Statement Problem 1 If all of the particles shown in the figure are electrons, what is the direction of the magnetic field that produced the indicated deflection? http://session.masteringphysics.com/problemAsset/1013281/5/jfk.Figure.24.Q35.jpg Choices Up (toward the top of the...

Homework Statement Work is done on an object far out in space where it has negligible gravitational-PE. If in the process there is no net change in KE, we can conclude a) friction may have been operative b) this situation is impossible c) the energy of the object has decreased d) the...

The question is here: http://dl.getdropbox.com/u/175564/logic.png The correct answer is D. My attempt to the problem: Let the beginnings of the sentences be A. In a, A is B -/-> C is D. In b, A is B -/-> C is D. These first two do not make sense. in c and d, the word "only" suggests...

Homework Statement Prove, without using the Axiom of Choice: if f: X->Y is surjective and Y is finite, there exists a 'section', a function s:Y->X such that f(s(y))=y for all y in Y Hint: perform induction over the cardinality of Y The Attempt at a Solution Induction over the...

I was reading about the Delayed Choice Quantum Eraser experiment here: bottomlayer.com/bottom/kim-scully/kim-scully-web.htm In this experiment the which-path info is erased or not at random AFTER the original (signal) photon hits the screen. The results of the screen are seen by the...

Which of these 3rd quarter 2008 papers do you predict will prove most valuable to future research? Significant papers tend to be cited more in subsequent research---we will soon have citation counts to go by, on some of these, as well as subjective judgment. Polling let's us share information as...

Does there exist a theorem, whose proof relies on the axiom of choice, and which has practical or concrete applications? I'll consider for example PDE and number theory problems practical or concrete, because they can be intuitively connected with the physical world. On the other hand, for...

John McCain's timing to announce Sarah Palin as his VP running mate was definitely successful at quickly turning the media's attention to his campaign after the big Barack Obama acceptance speech at the closing of the DNC. But the question that came up most was "Who is Sarah Palin?". Was she...

Hi everyone, I'm more of a programmer than a mathematician/physicist. However, my query on google and such, led me here and I think someone might be able to help me. I'm trying to create a program that guesses the next colour the user will select, based on previous selections. I've come...

Chadwick worked as personal secretary to Forbisher. He was given a list to type up that Forbisher was to submit to the London Telegraph puzzle editor within the hour because he was certain he had solved the puzzle. However Chadwick carelessly dropped a cigarette on the paper before he had a...

I am just coming into Year 13 in the UK and I need to choose which universities to apply to, at AS Level I got 5As in Maths, Further Maths, Bio, Chem and Physics so I have a free choice as far as entry requirements go with the exception of places like Oxbridge and maybe even Imperial where there...

Can someone give me a list of problems which at first sight require the axiom of choice, but do not?

I'm about to graduate and I should choose my graduation thesis. My choice will probably determine my PhD area of research so I want to choose wisely. That's why I need some help from guys who are deep in research waters. My areas of interests are solid state physics and plasma physics. My...

Consider the line element: ds^2=-f(x)dt^2+g(x)dx^2 in a coordinate system (t,x) where f(x) and g(x) are two functions to be determined by solving Einstein equation. But I can always make a transformation g(x)dx^2=dy^2 and then calculate everything in the (t,y) coordinate system. My...

hi all i am a high school student(in ontario) going on to university next year.i'm planning on going into life sciences and eventually get into med school. i'm stuck between the university of toronto and queen's university and was wondering if anyone can help me in my decision. I am hoping...

It seems strange to me that in such a simple case as the following the equation of motion depends on the choice of metric! In flat space we have say: \partial^{\mu}\partial_{\mu}\phi=\frac{dV}{d\phi} Suppose \phi depends on space alone and we work in 1+1 dimension. then \eta_{\mu...

The paper described at http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser rather intrigues me. While the results appear counter intuitive to us, the properties being tested are those of light, and since light travels at speed c, is it not the case that for light time stands still...

[SOLVED] [Multiple Choice] ...wavelength of an object. de Broglie wavelength 1. THE PROBLEM STATEMENT MULTIPLE CHOICE Which of the following would you expect to have the largest wavelength associated with it? (A) a quick-moving bee (B) an electron orbiting a nucleus (C) a slowly lumbering...

As a few of you may know I posted here recently asking for info on Computer Science. Today I had a conversation with a co-worker regarding that subject. Let me give a little bit of background info first. My co-worker is 18 and I'm 24. Nothing significant however the dude is fresh out of HS...

Could someone explain to me how the delayed choice experiment is described within the framework of the Copenhagen interpretation? (Double slit experiment with two slits open but a late decission to measure the path of the particle). I do not understand how the deterministic evolution of the...

In June 2007 I applied for a Ph.D. to some universities for Spring 2008.Up to November 2007, I didn't get any response from these universities. This in turn motivated me to apply for fall 2008. In spite of my despair , I applied to the top universities for the fall term. Howevre,one of the...

Hi folks, I am trying to choose between two PhD scholarships. They are both at the same university & both research groups have excellent reputations. I'm being pressured by the university to make a decision by Monday. They're British PhDs so I'm assigned to my research topic right from the...

Feel free to give your reasons. I voted yes, because too many useful theorems are thrown out the window if Axiom of Choice is rejected. I believe that these useful theorems outweigh the surprising (strange?) results that also arise from AC (e.g. every set can be well-ordered). Also, if AC...

I, by the first time, came across with the Axiom of Choice today, found it beautiful, of course. And I'm interested in seeing, ladies and gentlemen here, as mathematicians, what are your attitude towards that axiom, I mean, the stronger one (i.e. the infinite axiom of choice). For example, do...