Statistical Definition and 582 Threads

Hello guys, can you explain something to me please? :confused: Hmm.. looking for a way to insert an image. Well, just the link then: http://img105.imageshack.us/img105/1579/stuffjf8.png The blurry variables-things on the left are different input parameters, these are divided into 4 groups...

Hi, The students of statistics in my high-school have to do a project. The topic we have chosen is Educational Performance in Kolkata Schools and Its Relation to Gender and Gender Interactions. I outline our goals below: 1)Collect data about Madhyamik results (a centralised exam organised...

I have a paramagnatic solid, where the atoms have a spin S=1 , and a magnetic momentum \mu_{B} We have a magnetic field: \vec{B} Under the influence of B the atoms can take 3 value of energy e,-e,0 e=g.\mu_{B}.B The solid is maintained at a Temperature T and N number of atoms. The question are...

Does anyone understand thermodynamics? There are so many terms that I feel that I am doing the maths but not really understanding the physics. Is it better to do stuff from a stat physics way (which makes more sense) and derive the thermodynamic relations from there?

A very simple thing; I have to collect data with 4 different group size. Something like; Group A; 12.4, 17.8, 12.5 ... Group B; 15.2, 9.5, ... I simply want to know if the differences between the groups are statistically signifiant. I don't want anybody to explain the me the math, I just...

Hi fellow members, I would appreciate if you could help with the following problem, it has had me stumped! Prove the statistical distance between random variables X & Y Thank You, and have a great day!

Homework Statement My class is doing an assignment where we have to create a programme to convert the Hipparcos data from magnitudes to flux so that it when you plot a frequency histogram of the data you will have an approximation of a normal distribution. I've completed this OK, but I was...

Homework Statement describe one significant success and one troublesome failure encountered when classical statistical mechanics is used to explain the properties of gases. (7 marks) Homework Equations The Attempt at a Solution success- it is simple to and it would fit the...

My thermal and statistical mechanics class has been using Kittel and Kroemer's Thermal Physics as a textbook, and though it's an okay book, I find the notation extremely frustrating. My main beef with it is that I'm never quite sure what the context of certain quantities is. (If you have the...

So here is my question. Have a 2-D electron gas where: E = P(x)^2/(2m) + P(y)^2/(2m) Where p^2= p(y)^2 + p(x)^2 1. How many single particle energy states are there with momentum p? ( this may be a really simple question but I need a refresher.) 2. If there are N electrons is...

Can anybody tell if i can get solutions to the end of the chapter problems in "Statistical Mechanics" by R k Pathria?

Hi every body i have a problem and i want to make sure about my results. I tried to put my progress but my scanner doesn't response. So i wonder if anyone could help me to complete the problem. http://img297.imageshack.us/img297/5944/dddhs1.jpg REGARDS

Homework Statement The result n_{0 \gamma} = \left( \frac{k_BT_{0r}}{hc} \right)^3 \int_0^{\infty} \frac{8 \pi x^2 dx}{e^x-1} = 2 \frac{\zeta(3)}{\pi^2} \left( \frac{k_BT_{0r}}{hc} \right)^3 is obtained for photons by integrating over the Planck distribution appropriate for bosons. In...

is anyone of you learning Statistical Mechanics ? come and let's learn together! :biggrin: haha, I am currently taking statistical mechanics in my undergraduate 2nd year. This subject is so interesting! I would like to invite you all to discuss and debate about the our understanding of...

Just a quick ponderance on a statistical mechanics problem. "How many distinct spin quantum states has the orthohydrogen molecule?" Does one include the electron spin states in the calculation? I'm inclined to say yes, as they most definitely have spin and most definitely are a different...

Hi, 1- In the introduction of the concepts of partition function and canonical ensemble, a system is assumed to be in direct contact with a heat bath (a thermal reservoir) where energy can be transferred between them. All thermodynamical properties of the system can be deduced from the...

(I didn't know where to put this one, so somebody will eventually move it, I predict...) This is a absolute newbie-question, so don't be evil! Why does statistical mechanics deal with probabilities? ASAIK, statistical mechanics is built on classical mechanics, where it is possible to predict...

In the Hartree model of interacting electrons one assumes that the wave function is in the form \Psi(x_1, x_2, ..., x_N,t) = \psi_1(x_1,t) \psi_2(x_2, t) ... \psi_N(x_N,t) which of course is a quite crude approximation since it for example does not take into account Pauli principle. I...

Is there a mathematical method to determine the optimum sampling of data for probabilities? Flip a coin. Simplistically speaking from experience, it has a 1/2 chance of landing on either side. But what if it can land on its edge? What if it can fall through a crack? What if lava from a...

1. The problem Statement A cubic box of volume V=L^3 contains energy in the form of photons in equilibrium with the walls at temperature T. The allowed photons energies are determined by the standing waves formed by the electromagnetic field in the box. The photon energies are (h/2pi)Wi =...

I thought Statistical Interpretation of quantum mechanics is a very good alternative besides the orthodox interpretation. But I just can't explain the particle-wave duality from the statistical point. How could the Statistical Interpretation explain the interference effects in the Quantum...

I'm just finishing up a "Classical Thermodynamics" class. Here is a list of topics we covered: Chapter 1: Ideal gas, equipartition of energy, heat and work, heat capacities, rates of processes Chapter 2: Multiplicity of an Einstein solid, of an ideal gas, of interacting systems Chapter 3...

Does anyone know how to perform a statistical T-test? I have a set of data and I want to do a T test, but I'm not sure how to do one. Can someone give me instructions or let me know of a site that gives instructions how to do it? Thanks.

I have a homework problem that is kinda driving me nuts... Consider the case of an anharmonic oscillator with microsystem quantum states given by Ej = jhf - (lambda)(jhf)^2. Using the known harmonic expressions as a starting point, determine the corresponding expression for F1 and for F...

Hi there. In my homework, I had to calculate the variation of the pressure with the altitude for a classical gas. I know that I should calculate the density of particles per volume element. I found this pdf on the net (http://cannoli.mps.ohio-state.edu/phy847/phy847-p2.pdf) . If you see...

I'm working on a problem where I have a sample of 200 people. I have a total of 5 concepts which are viewed by each respondent, but are rotated so there is "no" bias due to viewing order. Obviously each concept does not have the opportunity to be in each of the 5 possible viewing positions...

Hello everybody, I'm a bit stuck on a statistical significance problem. I have the following data: The number of visitors for each of 2 web pages, and a number of conversions for each web page. (A conversion could be the number of visitors who completed the web form.) I would like to be able...

Hi I'm having a bit of trouble with 2 homework questions. Firstly, I need to show that (Heat Capacity/Specific Heat) = 1+2f using the fact that Cp= (1+f/2)Nk and Cv= (f/2)Nk I've tried to work this out by cross multiplying these, but I don't think I'm doing the maths right...

Does anyone else have a lot of trouble comprehending the derivations in statistical mechanics? To me the mathematics feels somewhat archaic. Somehow it just seems as though it'd be neater if it was dealt with using matrix or operator methods. I always have trouble with the concept of entropy...

Below 0.6K the heat capacity of liquid He is well represented by the equation Cv=(9.819 x 10^-3 K^-3)NkT^3 Given that transverse shear waves cannot propagate in a liquid, predict the phonon contribution to the heat capacity of He from the data c=238 m/s (speed of sound in liquid He) p=0.145...

Hi all, I have this problem which I don't even know how to start it! Any hint will be appreciated. "A set of telephone lines is to be installed so as to connect between town A and town B. The town A has 2000 telephones. If each of the telephone users of A were to be guaranteed instant access...

Hello all, I need to find the statistical significance (95% confidence interval) for 3 independent samples. From what I understand, in order to find the statistical significance for more than 2 samples, ANOVA (ANalysis Of VAriance) is employed. ANOVA fits in nicely with what I want to do...

This shouldn't be too hard but I'm struggling. Consider N identical particles in a box of volume V. The relation between their linear momentum and kinetic energy is given by E = c\left|\overrightarrow{p}\right|, where c is the speed of light. So, the Hamiltonian of the system is...

I've seen an approximation in a statistical mechanics book, given without any proof: \frac{<N!>}{<(N-n)!>} = <N^n> (1 + \mathcal{O}( \frac{1}{<N!>} )) I've been trying to work out a proof, but I'm simply stuck any ideas how it can be proved?

http://sciam.com/article.cfm?chanID=sa003&articleID=000051A6-DE14-1419-9E1483414B7F0000 Well, what do you all think?

Hi. Can anyone explain the meaning of this formula from statistical physics to me: S = -k\sum_r{p_r\ln p_r} Ok, I know that S is the entropy, the p's are probabilities of some sort - but somehow this is not satisfactory :-)

Supposing I have a face-down card containing one of the 26 english alphabet, but I don't know which one. Hence, the entropy is kln 26. But, if I were to open the card, now I know exactly what the alphabet is. Hence, the entropy now is zero. How can this be in view of the second law?

I am confused about statistical entropy and thermodynamic entropy. Are they actually the same?

I am trying to make the connection from statistical mechanics to thermodynamics for the isothermal isobaric ensemble. Partition function = (sum of)exp(-BEj-gamma*Vj). I have followed T.L. Hill [Statistical Mechanics, p. 67] but can not understand how he justifies dE=(sum of)EdP, rather than...

Hi. I'm having trouble with this statistical physics thing again. I am given this exercise: Problem 9 – A spin model In a solid at temperature T the atoms have spin 1 so that the m quantum number takes on the values m = 0, ±1. Due to an interaction with the electrostatic field in the...

I don't like to assume things without checking.. Is the distribution really a 'normal distribution' aka Gaussian? Is this an experimental result or a 'good enough' assumption?

I understand that a microstate is one possible distribution of energies that make up the system's total energy. But I can't understand why, in a monatomic gas for example (where there is only translational kinetic energy of atoms), there is a finite number of states. Surely that would mean that...

Heres the problem: When asked to explain the meaning of "statistically significant at the 0.05 level," a student says, "This means there is only probability 0.05 that the null hypothesis is true." Is this an essentially correct explanation of statistical significance? Explain. Help...

Hi. I need some useful and conceptual book in advanced statistical physics. I can understand the mathematics in some famous book such as Pathria, but I have trouble understanding some concepts in that area. Any suggestion?! Thanks in advance. Somy

If 408 people try to guess someone's birthday, how do you calculate the chance of 13 of them being right? http://www.greasypalm.co.uk/gpforum/forum14/363.html

I was searching for references on statistics and found this - StatSoft Electronic Texbook - http://www.statsoft.com/textbook/stathome.html Elementary Concepts in Statistics - http://www.statsoft.com/textbook/esc.html Basic Statistics - http://www.statsoft.com/textbook/stbasic.html

Hello Gentlemen, Here's a statistical question for you: A man and a woman mate to produce a child that either has blue eyes (B) or green eyes (b), where blue eyes are dominant to green eyes. As you remember from biology, there are 3 different possibilities for the genotype - BB, Bb, or...

Let be an statistical system of N particles with their Hamiltonian.. H=\sum_{i=0}^{N}\frac{p_{i}^{2}}{2m}+V(q1,q2,...,qN) then you could obtain their equations of motion in the form: dp_{i}/dt=-dH/dp_{i} and dq_{i}/dt=p_{i}/m but of course if N is big you could take years and...

This isn't a homework question. I'm studying this from a book (Thermal Physics by Kittel & Kroemer) currently. Up til now I've had no problem following it. There's one derivation that's got me a little stumped however. I had thought my calculus was proficient enough, but I'm just not seeing...

it's just not sinking in.. i know a cell in phase space has 6 dimensions, 3 for momentum and the other 3 for position. but i'd like to understand it(phase space). can someone give me an example maybe or tell me why this constuct is needed?? or a link to a very good description?