Significance Definition and 264 Threads

  1. Q

    Wave Equation: A = A cos (kx - ωt), Meaning & Significance

    a wave equation is given as A = A cos (kx - ωt) so why if someone describes the wave equation to be A = A sin (ωt - kx) , the argument of the sin function changes by a minus sign? and is there a meaning to it? also i still don't really understand why the minus sign in the first equation...
  2. S

    Statistics tests of significance

    For the following tests of significance 1 tests of mean difference for paired data - differences a calulated - forms a new random variable test its mean 2 two sample normal tests - looks at the differences in averages i have trouble picking which one to use for problems, i mean...
  3. K

    Why Is the Hermiticity of the Density Operator Important in Quantum Mechanics?

    Hi there, In all text of QM I have, they tells that the density operator is hermitian. But without considering the math, from the physics base, why density operator must be hermitian? What's the physical significane of the eigenvalue of density matrix? Thanks
  4. snoopies622

    The significance of commutation

    I'm in chapter two of H. S. Green's Matrix Mechanics and at a sticking point. In section 2.2 he gives the following scenario: An atom emits a photon with angular velocity ω, it has energy Ei before the emission and Ef after, so Ei - Ef = ħω. (That I can understand.) ψi and ψf are...
  5. A

    Avoid Loss of Significance in Function: Tips & Advice

    Homework Statement Hey guys. Anyone knows how can I avoid loss of significance in this function? http://img402.imageshack.us/img402/4216/33365715.jpg Thanks a lot.Homework Equations The Attempt at a Solution
  6. O

    Significance of Special Relativity

    Allow me to preface this by saying that I am only a student of physics, and that I have much respect for the work of those who came before me. I have familiarized myself with SR through my own research on the internet (perhaps a grave error), and I am quick to acknowledge that I do not...
  7. A

    Significance of non-linear terms

    hi, Do the addition of non-linear terms in action play any significant role in string theory?? if so, what is its significance in string cosmology? --- anuradha
  8. X

    What is physical significance of g factor?

    In quantum mechanics, magnetic moment is equal to g factor times (gyromagnetic ratio x angular momentum). For orbital angular momentum, g=1, for electron spin angular momentum, g=2, for proton, it is 3.56. Is there any physical significance for this factor? why scientist introduce this factor...
  9. T

    Physical significance of the laplacian operator?

    What is the physical significance of the laplacian operator? The laplacian operator is the divergence of the gradient. I understand the intuitive meanings of both. The gradient when dotted against a unit vector gives the rate of change in that direction. The divergence is the flow in or out...
  10. H

    Significance of spring mass in SHM.

    Homework Statement So, we are considering a spring-mass system, in which the mass at the end of the spring, M, is comparable to the mass of the spring, m. Using Newtons laws, I have to calculate, how significant the mass of the spring is. Homework Equations Mass at the end of the...
  11. maverick280857

    What is the physical significance of the commutator in the Virial Theorem?

    Hi everyone I have a question regarding a step in the proof of the Virial Theorem. Specifically suppose |E\rangle is a stationary state with energy E, i.e. \hat{H}|E\rangle = E|E\rangle Now, [\hat{r}\bullet\hat{p},\hat{H}] = i\hbar\left(\frac{p^2}{m} - \vec{r}\bullet\nabla...
  12. E

    Is the Limit of a Function the Slope Around a Point?

    1) can we say limit of a function f(x) such that limitx\rightarrowa f(x) gives the slope of this function around this point x = a. 2) can we say that to find slope i.e. limit of a function f(x) we always need a point "a" such that limitx\rightarrowa f(x) = slope 3) can we say that if left...
  13. M

    Significance of prokaryote evolution to enable multi-cellular life to exist?

    That is, if these cells even had anything to do with it. We're only going by the endosymbiotic theory.
  14. N

    Why Does Pi Appear in Various Mathematical Solutions?

    What is the physcial signifcance of pi's appearance in a mathematical solution, if any?? Pi, the circumference of a circle divided by diameter, shows up in all sorts of mathematical solutions..classical, quantum, sometimes in unexpected mathematical results. As an example, Unruhs law is...
  15. K

    Is r = –0.405 Significant at 5% for n = 22?

    Determine whether a correlation coefficient of r = –0.405 is significant at the 5% level for a sample size of 22.
  16. S

    What is the significance of graph intercepts in photocell experiments?

    Can some help me to solve this question I have no idea where to start a) What is the physical significance of the intercept of the graph with the frequency axis (x-axis)? b) What is the physical significance of the intercept of the graph with the kinetic energy axis (y-axis)? c) Use the...
  17. M

    What is Physical Significance of Lorentz Transforms ?

    What is Physical Significance of "Lorentz Transforms"? Can anyone explain me what is physical significance of "Lorentz Transforms"? That means, apart from the math, how can we understand "how and why" length contraction or time dilation actually happen? and what is speed of light doing in...
  18. V

    Significance of AVcc pin in ATMEGA 16

    I'm using a ATMEGA16 microcontroller. I was having problem getting it to work. I found somewhere on the internet that even if I'm not using the analog signals, I need to short the AVcc pin to the Vcc. Can anyone give any reason as to why we need to do this?
  19. maverick280857

    Significance of 1/s in Root Loci & Nyquist Stability

    Hi Suppose we have a closed feedback system with loop gain = L(s) = G(s)H(s). The characteristic equation is 1 + L(s) = 0 What is the significance of the transformation s \rightarrow 1/s and what bearing does it have on root loci and Nyquist stability? I can see that the points s =...
  20. S

    Significance of Average value of a AC signal

    [SOLVED] Significance of Average value of a AC signal Hello, I would like to know the significance of average value in a AC circuit. Let's consider a sinusoidal ac source with only a resistor in the circuit. The rms value of voltage and current indicate the equivalent DC value which would...
  21. Y

    Heat Exchangers: Significance, Elements, & Usage

    can anyone explain me the 1>significance 2>elements used to construct them 3>main usage to which industries of heat exchangers?
  22. G

    Significance of Surface and Coulomb Terms

    I recently had a test question posed to me that asked firstly for an explanation of the terms in the semi empircal mass forumla (which I gave correctly) but then went on to ask: For ^{40}_{20}Ca and ^{208}_{96}Pb estimate the fraction of the binding energy provided by the surface and...
  23. T

    Significance of a singular matrix

    So I have a system of equations (composed of force and moment eqns) and I can split them up into matrices which will then look like this: Ax = B I know the matrices A and B are correct, because when I plug in known values for x from a working prog, I get the correct values for B. So that must...
  24. S

    Significance of the hamiltonian commuting

    Wht is the significance of an operator commuting with the hamiltonian?? Its definitely more than them being measurable simultaneously and precisely!
  25. C

    The Physical Significance of Tensor Product

    what is the tensor product's physical significance? I know what it does mathematically, but what does it mean. I have looked on textbooks and wikipedia but i still can't understand the physical signifcance.
  26. S

    What is the Physical Significance of Eigenvalues and Eigenfunctions?

    what is a eigen value and eigen function? i have read a lot abt it...i understand the math behind it.. what is its physical significance of it?
  27. I

    Number 47: Uncovering Universe's Basic Structure

    Is there a significance of the number '47' in the 'Basic Structure' of the universe? Does this number represents in any way the basis of the structure of the universe?
  28. C

    The Lie Derivative: Physical Significance & Tensor Analysis

    what is the physical significance of the lie derivative? What is its purpose in tensor analysis?
  29. S

    What is the physical significance of the divergence?

    Hello; I remember the days of muti variable calculus. The man said that divergence is equal to del dot the vector field. So on the exam he gave us a vector field, and I did del dot the given vector field and won big time. The other day I decided my concentration would be...
  30. L

    The significance of orthogonal relationships

    what is the meaning of orthogonal relationships in addition to right angles in the xyz coordinate system? for instance, if a 3 piece rocket separated in space in an orthogonal way...will there be any significance when compared to the 3 piece rocket that does not separate in an orthogonal...
  31. D

    Poisson bracket significance (Classical Mechanics)

    We have to show that [Lx,Ly] = Lz [Ly,Lx] = -Lz [Lx,Lx] = 0 and I have done this. We then need to comment on the significance of these results, which I'm not sure of. I know in QM you get similar results for commutators of these quantities, and it means that you can't simultaneously know...
  32. N

    Geometric Significance of A=e(A.e)+e x (A x e)

    Homework Statement Let A be an arbitrary vector and e be a unit vector in some fixed direction.Show that A=e(A.e)+e x (A x e) What is the geometrical significance of each of the two terms? Homework Equations The Attempt at a Solution I can show it easily.As the first term (a dot...
  33. A

    Understanding Chiral Theory & Its Significance

    Could somebody please tell me a workable definition of the term "chiral theory" , and also explain its significance? As far as I know, in a chiral theory not all the fermions obtain a mass but whether this is a definition or a derived result is not clear to me. Thanks in advance
  34. S

    Physical significance of othogonality condition?

    what is the physical significance of othogonality condition? or what is meant when we say that two eigen states are orthogonal?
  35. P

    Statistical Significance Question

    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...
  36. S

    What is the significance of R Parity in SUSY physics?

    what is R Parity and why?
  37. S

    Determining Sample Size for Statistical Significance

    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...
  38. N

    Statistical Significance for 3 samples

    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...
  39. tony873004

    Is Phi More Than Just a Fun Mathematical Curiosity?

    Is there anything significant about phi, other than 1 + phi = phi^2 ? Is this just fun number trivia, or is phi actually useful to science, etc...?
  40. H

    Deriving Newton's Law of Gravitation: Understanding the Significance

    Newton's Law of Gravitation Derivative Hi, I was wondering if anyone could help me find the derivative of Newton's Law of gravitation [F=(GmM)/r^2] and what it means? What does the minus sign indicate? I'm kind of confused on the subject at hand and hopefully someone can help out. Thanks
  41. A

    Physical significance behind [H, rho]=0

    In using the Maximum Entropy Principle to derive the non-equilibrium steady-state statistical density operator in quantum transport, I've seen the following constraint used to let the closed quantum system be in steady-state: [H, rh] = 0 I still don't understand the physical significance...
  42. B

    What Are Primitive Roots and Why Are They Important?

    I was curious why primitive roots are so important? Also, how one would find out if a number has a primitive root and what and how many of them they are?
  43. J

    Statistics: Statistical Significance and Null Hypothesis

    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...
  44. W

    What is the Impact of k on Wave Behavior and Its Physical Significance?

    The problem gives the angular frequency of a light wave (w) is represented by e^iw(t-nx/c) it says that sometimes n is replaced by the complex quantity n-ik. The question asks what is the effect of k on the wave. Also, it asks, what is its physical signifigance? I tried...
  45. H

    News 9/11: Uncovering its Significance

    Can you give me a reason to think 9/11 was significant?
  46. A

    Botany: what is the evolutionary significance of losing a cotyledon?

    Hey there, I was reading up on angiosperms, and one of the possible evolutionary relationships that showed up were ancestors that originally had 2 cotyledons, and the lost of one later on rose to the arisal of monocots. I suppose this might be a really tough question, but what would be the...
  47. S

    Geometric Significance of the Dihedral Group D/o

    Consider the dihedral group D/o, generated by x and y where o(x)=2 and o(y)=5 What is the geometric significance of D/o? Which of G/<x> and G/<y> are well defined groups? Give reasons?
  48. R

    Significance of isospin and hypercharge

    This may sounds like a dumb question but I want to figure out the 'point' of them. I know that isospin was an attempt to describe the proton and nucleon as an isospin doublet and that hypercharge seems to me to be a nifty little relation between the electric charge and the isospin - but what...
  49. I

    Uncovering the Historical Significance of Lincoln's Reconstruction Plan and More

    Hi! I am currently in a Honors US history class with a teacher who seriously pushes us to our very limits (seriously!) with his evil ID tests. These tests require us to learn about 20-30 key terms in US history starting from the beginning (1700's) each week. Right now, in week 3 we've gotten to...
  50. quasar987

    Physical Interpretation of a Wave Packet: Single Beat Wavepacket

    In my wave final there was a quetion that went "Write the most general expression for a wave paquet in terms of a Fourier integral and explain what this integral corresponds to physically." What would have you answered to the second part of the question?
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