Standard Definition and 1000 Threads

Hi I used the last few month two make me familiar with quantum mechanics and read two books. The Feynman lectures on physics and Principles of Quantum Mechanics (R. Shanker). I think I have no problems with the bra-ket notation and solving the Schroedinger equation for some simple particle...

For sets X and Y, is it true that s_{XY}=s_{X}\overline{Y}+s_{Y}\overline{X}, where s represents the standard deviation and XY is the set containing x_{i}y_{i}?

Homework Statement Hello, My book has all of 1 page about wreath products and standard wreath products. I'm really lost on this topic and I have 4 homework problems using it. Does anyone know where I could find a little more info on the topic? Homework Equations The Attempt at a...

my teacher says that if you add acid to the solution then you don't use the H2) half reaction with the (10-7 M), but that you still do if you add a base. Is this true?

I have to find the maximun bps that it can be reach using a point-to-point link of 40 km long of optic fiber. I use an ITU normalized channel (100 GHz optic BW). So, I can choose any electric modulation and any optic modulation, too. Anybody could help me? Any answer is welcome. Thanks.

Read gambling problem/Standard deviation Posted: May 23, 2007 4:57 AM Click to edit this message... Click to see the message monospaced in plain text Plain Text Click to reply to this topic Reply I'm analyzing some data from online gambling sites.I'm trying to prove they are...

how are they done at the college level? I would relaly like to compare actualy college level lab reports to my AP chemistry level lab reports. I know that they are usually done in pen and paper, but if someone could scan one so i could look at it I would greatly appreciate it thanks.

Homework Statement Hello, I'm trying to find the limit(as n approaches 0) of [1-cos(n)]/(n^2). I have done a few of these before and haven't had to much trouble, but they all have been as n approaches infinity. Homework Equations I think the n approaches 0 is confusing me. The...

Homework Statement Need to see if what I am doing is right, here is the problem: z= 4i/(-1+i), express z^20 in standard form. so, z= 4i/(-1+i) = 2-2i z^20 = 2*sqrt(2) x cis[20(-pi/4)] = 2*sqrt(2) x cis(-5pi) = 2*sqrt(2) x [cos(-5pi) + i sin(-5pi)] = 2*sqrt(2) x [-1 + 0i]...

Very basic question which has confused me: if the variance of an expectation value <A> is: uncertainty of A=<(A-<A>)^2>^0.5 how is this equal to: (<A^2>-<A>^2)^0.5 ??

Hi, I'm tying to solve the fourth moment of pdf of standard normal pdf. meanwhile, i have to break this one: how to get the result of integral of x exp (x) dx. that would mean a great difference to me. thank you.

Homework Statement Use half-reactions and E's to determine the result of storing a solution of CuSO4 in a tin container. Homework Equations [Table of Standard Reduction Potentials of Half-Cells] The Attempt at a Solution My question isn't exactly how to do this question. I was just...

I wrote a program that is supposed to find the standard deviation of a set, but something really strange happens in a for loop that I have in my main function. int main() { int i=1; int NUMBER_OF_ELEMENTS; double data[NUMBER_OF_ELEMENTS]; cout << "Please enter the number of...

Hi Is there anywhere a list of all constants (with their values) and fundamental equations (which can not be constructed from any other equations) of the standard model? thx einKI

I need some help here. I need to have a standard PPM servo interface with MATLAB so that I can give it a command in simulink and have a response. I found this device, which eliminates the need to use PPM in simulink. http://www.parallax.com/detail.asp?product_id=28823 Basically, it...

Hi. Can oxalic acid be used as a primary standard to standardise a basic solution, such as sodium hydroxide? I can't think of any reason why it couldn't be used, but i could very much be missing something.

Just as x^a-1 = (x-1)\sum_{n=0}^{a-1} x^n, is there a similar expansion for x^n - y^n?

Quadratic in standard form help...please Homework Statement Write the quadratic function f(x) = x^2 + 3x + 2 in standard form. Homework Equations Standard form equation : f(x) = a(x-h)^2 + kThe Attempt at a Solution Ok, I think I got this one but am wanting to be sure. I set it up : (x^2...

http://background.uchicago.edu/~whu/araa/node3.html I found this site, would it be a good reference?

Standard Deviation Problem in Physics. Help!? Homework Statement In working with Wheatstone bridge one student chose the value for R1 so that the bridge is balanced at L1 = 48.5 cm and L2 = 51.2 cm. If Each measurement has an uncertainty of +/- .05, what would be the minimum value for the...

Homework Statement In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizen are chosen, what is the standard deviation of the number favoring the substation? Homework Equations I know that my mean is 15 and the probiblilty is 80...

Hi everyone, Can anyone explain the following to me? Given a basis beta for an n-dimensional vector space V over the field F, "the standard representation of V with respect to beta is the function phi_beta(x)=[x]_beta for each x in V." This is from my textbook. It then proceeds to give...

I have a question about standard deviation. If I have a hundred of distance data, how can I use standard deviation to choose a suitble range of the distance. What is the relation between standard deviation graph and my data. I can plot a graph using mean and std of the data, but do not know how...

R. G. Vishwakarma has replaced his paper Recent Supernovae Ia observations tend to rule out all the cosmologies? with the accepted version. He does not say accepted by whom. (Emphasis mine) Does the high-z SNe Ia data record the evolution of Dark Energy, i.e. \omega, or the evolution of the...

Exam is in the next 30 mins so please reply ASAP. I just need help with this question. For a sample of size 5, x1 - mean = -5, x2 - mean = 9, x3 - mean = -7, x4 - mean = -2 and x5 - mean = 5 What is standard deviation... answer is 6.782 by squaring all the answers, dividing by n-1 and...

Cohen-Tanoudji defines a "standard basis" of the state space as an orthonormal basis {|k,j,m>} composed of eigenvectors common to J² and J_z such that the action of J_± on the basis vectors is given by J_{\pm}|k,j,m>=\hbar\sqrt{j(j+1)-m(m\pm 1)}|k,j,m\pm 1> But isn't is automatic that such...

Homework Statement This is my data: 42.4, 65.7, 29.8, 58.7, 52.1, 55.8, 57.0, 68.7, 67.3, 67.3, 54.3, 54.0 I need to find the standard deviation of this list of data. 2. Homework Equations standard deviation= : s^2=\frac{\sum_{i=1}^n(x_i -\overline{x})}{n-1} Actually the standard...

Does anyone have any idea of general guidelines defining the minimum temperature at which a commercial flight can take off the ground? I understand that they generally use the criteria of ice to determine activity, but at a certain temperature is there a point of no go regardless of temperature...

Kea tells me that a good first book to read to learn category theory is Sets for Mathematics $45 F. William Lawvere and Robert Rosebrugh Advanced undergraduate or beginning graduate students need a unified foundation for their study of mathematics. For the first time in a text, this book...

Hi, I'm having trouble following the following derivation I have seen in a textbook: The derivation goes as follows: L0P3+L1P2+L2P1=0 This is a Poisson eqn for P3 with respect to L0 which requires <L1P2+L2P1>=0 <L2>=L(BS)(sigma) <L1P2>=.5<L1.phi(y)>.x^2. d^2P0/dx^2 thus...

Have there been any theories in recent decades that suggest one? Or more? I know it may seem unnecessary or even frivolous, but theories beyond the standard model are, after all, grappling with issues like how the entire universe and its four forces came to exist. Has anyone postulated a fifth...

The problem You have two indistinguishable envelopes in front of you. Both of them contain money, one of them twice as much as the other. You're allowed to choose one of the envelopes and keep whatever's in it. So you pick one at random, and then you hesitate and think "Maybe I should pick the...

I know this topic has already been covered many times, but, is it possible to explain classically or semiclassicaly the standard Compton effect?

Pulling an Unwinding Spool vs. Standard Block Homework Statement This problem is done on a frictionless surface There is a block pulled by a string with tension T. Next to it, there is a spool with a string wrapped around it and may unwind. It is pulled with the same tension as System A...

Two interesting papers by Chan and Tsou on the hep-th arxiv: hep-ph/0611363 Title: Higgs Fields as Vielbeins of Internal Symmetry Space Authors: H.M. Chan, S.T. Tsou Comments: 24 pages An earlier suggestion that scalar fields in gauge theory may be introduced as frame vectors or...

feso4 is not a primary standard?? hi ppl, someone plssss help me---why is feso4 not a primary standard?

A department store has determined that 25% of all their sales are credit sales. A random sample of 75 sales is selected and the proportion of credit sales in the sample is computed. a) What is the probability that the sample proportion will be greater than 0.34? my answer is: n=75 p=0.25...

"Beyond the Standard Model" hep-ph/0611279 Beyond the Standard Model Authors: Dmitri I. Kazakov Moscow 2006 Report-no: 2006 Review of recent developments in attempts to go beyond the Standard Model is given. We concentrate on three main unresolved problems: mechanism of electroweak...

Hey all. Im doing maths methods 5 (i live in Australia) and I've run into this problem. A university study investigated the increase in heart rates(measured in beats per minute) of people undertaking a particular exercise. The increases in heart rate were normally distributed with...

I put a notice of this earlier today in the QG links thread https://www.physicsforums.com/showpost.php?p=1134904&postcount=529 https://www.physicsforums.com/showthread.php?p=1134904#post1134904 This thread is in case anyone wishes to discuss the paper: http://arxiv.org/abs/hep-th/0610241...

I've google and read, but could anyone tell me how to find out the standard enthalpy of formation for any compound? :confused: thnx

I would like a little clarification in how to prove that the k topology on R is strictly finer than the standard topology on R. They have a proof of this in Munkres' book. I know how to prove that its finer, but the part that shows it to be strictly finer I am not sure. It says given the basis...

Here's the problem: We are ascending in an elevator at sea level. Our eardrums feel a 1 percent decrease in pressure per minute. Calculate the upward speed of the elevator. My solution: *I am using the equation p1/p0 = (T1/T0)^(-g/aR), where p1 and p0 are pressure at point 1 and point 0...

How is it not an exactly accurate understanding that QCD is a part/sector of the standard model of particle physics ? Or, it actually is?

http://arxiv.org/abs/astro-ph/0608324 Cosmological Implications of the Second Parameter of Type Ia Supernovae Authors: Philipp Podsiadlowski (Oxford), Paolo A. Mazzali (MPA, Munich; Trieste), Pierre Lesaffre (Oxford, Cambridge, Paris), Christian Wolf (Oxford), Francisco Forster (Oxford)...

how many propreties of particles of the standard model has lqg been able to describe within its conceptual framework, as opposed to string theory? recently i posted "lee smolin & standard model" evidently loop quantum gravity might be able to model some elementary particles properties...

http://www.newscientist.com/channel/fundamentals/mg19125645.800 sounds like string theory, all particles from vibrations. how successful has this theory been in comparison to string theory, on particle physics? "physical particles may seem very different from the space-time they inhabit, but...

http://arxiv.org/abs/hep-ph/0608079 CP Studies and Non-Standard Higgs Physics Authors: S. Kraml, E. Accomando, A.G. Akeroyd, E. Akhmetzyanova, J. Albert, A. Alves, N. Amapane, M. Aoki, G. Azuelos, S. Baffioni, A. Ballestrero, V. Barger, A. Bartl, P. Bechtle, G. Belanger, A. Belhouari, R...

This is page #293 of the 1-st volume from 2-nd edition of Apostol's "Calculus & Linear Algebra". Well, the question goes like this: Can you find a flagrant error in this page...? Daniel.

No crackpot stuff her please, i would like a collection of known scientists thoughts that are beyond the standard model, Hawking has some good stuff :zzz: what are your favourites?