Significance Definition and 279 Threads

Hello All, I have been trying to understand the exact contribution of our legendary physicist, Dr.Hawking and found that Hawking radiation is amongst one. Is it that Hawking radiation is the first attempt to unify, general relativity, quantum mechanics and thermodynamics which led to the...

I have done several exercises concering periodic potentials in crystal. Especially I did one, where I had to show that the Fourier component of the shortest reciprocal lattice vector (call this vector a) in the z-direction was zero. Now solving the problem was just about writing up the right...

hey everyone, I have a questions, that is very general, and perhaps, silly... but why are coils so significant in terms of electricity and magnetic fields? why is it when you push a magnet through a coil, you get a charge, but not when you touch it to a straight copper pipe? Or when you see...

Standard Pauli spin matrices are: Sx: $$\left(\begin{array}{cc}0&1/2\\1/2&0\end{array}\right)$$ Sz: $$\left(\begin{array}{cc}1/2&0\\0&-1/2\end{array}\right)$$ The Sz eigenvectors are Z+ = (x=1,y=0) and Z- = (x=0,y=1). These yield eigenvalues 1/2 and -1/2 respectively. Similarly...

Two polynomials are considered orthogonal if the integral of their inner product over a defined interval is equal to zero... is that a correct and complete definition? From what I understand, orthogonal polynomials form a basis in a vector space. Is that the desirable quality of orthogonal...

Hi all, I have a doubt regarding the physical significance of eigen vectors of the covariance matrix. I came to know that eigen vectors of covariance matrix are the principal components for dimensionality reduction etc, but how to prove it?

A question in regards to nomenclature. I am curious as to the significance of using the symbol π for a time-independent distribution. Does it have any relation to the number π or circular geometry? Or does it come maybe from the invariance of i in the P Matrix such that Pi,j → πj? I don't like...

Sen 2013 says, How serious a problem is this for LQG? Does this mean that LQG doesn't have GR as its semiclassical limit? Does that mean it's a dead theory, or maybe just that it needs to be modified? Is the technique using Euclidean gravity reliable? Since I'm not a specialist, I'd be...

Is there an intuitive explanation of why E/w = 2*L, where E/w is the ratio of the energy of any photon to its angular frequency and L is the magnitude of the spin of any electron? Evidentially there is a mathematical derivation of L=hbar/2 from some base assumptions, and evidentially E=hbar*w...

I have a set of data that was recorded from an engine that we are testing. We've noticed lately that a particular pressure value will sometimes spike with no apparent explanation, as seen in the attached graph. The pressure in question is passively regulated by a pump, but it is also dependent...

Hello. I was just wandering if anyone could help. I've been doing a couple of statistics questions, and when they ask for some questions, I am not sure if I have an appropriate understanding of what the right answer should be. I would really like to understand this material, so what I want to...

Hello, I am confused as to the physical significance of the dot product of B and ds. Why would we evaluate this scalar product. My textbook has it on here without any motivation for it. Also, why is the analogous gauss' law used with flux, yet magnetic flux doesn't use amperes law?

Homework Statement Just trying to understand something my instructor said. For large n, the volume of the sphere exists in a thin shell at its surface. He asked us what relationship this has to statistical physics. Homework Equations The Attempt at a Solution The only thing I can...

Apparently : What significance does brownian motion has to do with coal explosion?[Brownian motion or pedesis is the presumably random moving of particles suspended in a fluid (a liquid or a gas) resulting from their bombardment by the fast-moving atoms or molecules in the gas or liquid.] Now...

Hi, I am revising my intro to nuclear physics class and was wondering why is parity so important ? I mean OK, I get it, physicists are crazy about symmetries, but I do not understand what does it physically mean... I was wondering if someone could possibly talk me through its importance and...

After normalising a wave equation, let's say psi = A*e^(-r/a), and finding that A = +/- sqrt(2/a), what does this mean in terms of the physical significance of the wave? Would the wave just be a superposition of two waves with the two different A values?

I am trying to understand the relationship between p-values and Type II error rate. Type II error occurs when there is failure to reject the null when it is false. As an example, suppose that I find that my results are not significant. In this case, the p-value is increased, or higher (in...

I've poked back through the past few weeks of threads, and I've only seen two posts (here and here) with very little discussion commenting about the recent Huge-LQG discovery (http://mnras.oxfordjournals.org/content/early/2013/01/07/mnras.sts497.full). I was hoping some cosmologists could...

I've been doing some review of particle physics in Griffiths and I came across this statement that really didn't stand out to me before. "the idea is to draw all the diagrams contributing to the process in question (up to a desired order), calculate the amplitude (M) for each one, and add...

Let us denote by X^i=(1,\vec 0) the Killing vector and by u^i(s) a tangent vector of a geodesic, where s is some affine parameter. What physical significance do the scalar quantity X_iu^i and its conservation hold? If any...? I have seen this in may books and exam questions. I wonder what it...

If this seems like a homework question please forgive me, but it is merely for understanding and confidence building. I've been reading into the Bohr Model and the Wave Mechanics Model and I read through de Broglie and have proceeded to Schrodinger, Heisenberg and Dirac. At this stage, my mind...

Hello everyone! I'm curious to know what is the significance of the Eigenvalues of a covariance matrix. I'm not interested to find an answer in terms of PCA (as you of you may be familiar with the term). I'm thinking of a Gaussian vector, whose variance represent some notion of power or...

Back in 2008 I posted the same topic [thread now closed, due to age??: C:\Users\Owner\Documents\PHYSICS\What's the significance of pi.mht We missed a fascinating answer I just noticed: In natural units, commonly used in high energy physics, where the Coulomb constant is 1/4π and c = ħ = 1...

So this has crept up in another thread in which another member said that the problem they have with my posts is that I always assume some sort of significance. I just kind of wanted to touch on that and see if anyone else thinks the same.* A lot of people have the view point that, the...

I understand that stimulated emissions produce coherent photons. What happens as a result of their coherence? My guess is that the laser beam does not spread out as much allowing it to travel further. Also, what is the property of a laser that allows the beam to travel great distances?

Hi all, I was deriving the free electron gas for practice in 1, 2, and 3 dimensions, and I started wondering why they have different dependencies on energies and what that means. I got: 1D: ##g(E) = \frac{1}{\pi\hbar} \sqrt{\frac{2m}{E}}## 2D: ##g(E) = \frac{m}{\pi\hbar^2}## 3D: ##g(E) =...

I've read that gauge invariance leads to a fundamental phenomenon.What is that? Thanks

Thermochemistry significance of "infinitely dilute solution" Homework Statement (see attachment) Homework Equations The Attempt at a Solution I don't know where to start from and it seems to me that data given is insufficient to solve this problem. Also, what's the significance...

Hi I'm trying to determine the significance of a compact subset of a metric space in relation to calculus in general. I know the definition: A subset \small K of a metric space \small X is said to be compact if every open cover of \small K contains a finite subcover. But what is the...

What is the physical significance of Refractive Index(RI) ?

Can you always put numbers directly into an expression which has the delta triangle against its variables? For example Faraday's Law is always shown with the delta triangle on top and bottom yet these are dropped when you use it for calculations; which leaves me wondering why they are there in...

Hello friends ! I got confused in the point that how can a body exert a gravitational force on other body without coming in its physical contact ? Also please explain its mechanism or significance of gravitational force ?

I have idea of physical signif of var(x),cov(x) but can't get derivations of equation. Hi all, I understood the facts that variance indicate the spread in random variable and covariance shows correlation between 2 r.v s etc. But I cannot imagine how we are arriving at their...

What is the significance of the Poisson kernel (besides solving the Dirichlet problem)? What is the Poisson's role in solving the Dirichlet problem? I know it is the solution but what is meant by its role?

Will anyone help me to understand the concept of reduced mass , where does it come from and its physical significance

I've been searching for some indication of the "significance" of higher order derivatives, but without much luck. Perhaps someone here can offer some insight. The first derivative of a function f(x) (with respect to x) gives the slope of the tangent to the curve of that function. When this...

I am having some trouble understanding the significance of negative work. If the work that I do on object X is W, is it equivalent to saying that object X does work on me equal to -W ? After all, work is scalar, so I can't fathom the physical significance of negative work. Also...

Hi! Can anyone help me out with ascertaining how to go about preparing for a course in Electronic Printing and Media technology from a reputed International university? I understand that the recent developments in this field have been unparalleled (they have just fabricated paper-thin...

In what way is compound vortex controlled combustion effective ? and does it effectively reduce emission?

How important do you think is the "reputation" of the college that one joins after high school, especially for physics ? I've seen a lot of "fools" going to big name colleges , which charge exorbitant fees ,and getting those top jobs, whereas the talented and hard working from relatively...

Why is row space of a matrix important?

significance of commutation of operators? how do u show that the position and momentum operators do not commute?

The basic concepts used in physics are mostly derived from everyday human experience. Hardly surprising for a subject which usefully describes our contingent physical circumstances. For example dynamics involves ordinary and familiar concepts like mass, and changing distance is described as...

What is eigen value, eigen vector etc and what is their physical significance? -Devanand T

Gap exponents are denoted like critical exponents for higher derivatives of Gibbs potential. \Delta_l' (\frac{\partial G}{\partial H})_T=G^{(1)}\propto (1-\frac{T}{T_c})^{-\Delta_1'}G^{0} (\frac{\partial^l G}{\partial H^l})_T=G^{(1)}\propto (1-\frac{T}{T_c})^{-\Delta_l'}G^{l-1} \alpha'...

Why are snap rings used in turbocharger core assembly ,and how important are they ?

For single variable functions derivative means slope of tangent what does it mean for functions of more than one variable. book says that a function is said to be differentiable if: f(x + Δx , y + Δy) - f(x , y) = AΔx + BΔy + ε'ψ(Δx , Δy) + εh(Δx , Δy) WHERE ε, ε' → 0 AS Δx , Δy → 0...

(MAJOR EDIT: I think I missed the associative part, is that more or less my only mistake?) I've got an un"well-formed" question, I've been staring at things like every ring is a module over itself, counting the number of sets and operations in various definitions of algebraic objects. I was...

It is stated that kinematic viscosity is the ratio of dynamic viscosity to density. can anyone elaborate it further that what are the uses of both types of viscosities and why we differentiate them.does dynamic viscosity reates with static fluid?

I am supposed to discuss the benefits of having high number of magnetic poles in ac generators with constant frequency. From formula it is obvious that the higher number of poles the lower the speed of rotation. But is there anything else, or what is the benefit of lower speed? The only...