Significance Definition and 264 Threads

The following appears as part of an intro to statistical significance. I don't quite get it and hence the appeal for clarification. Someone claims that a newly invented medical test T is 99% accurate. To check their claim the test is conducted among 100 subjects and in 95 the result is...

Can anyone explain the meaning behind a mobius strip? Basically just a means to travel on both sides of a flat surface? It's still a 3D object though since it uses 3D space for the twist to be possible?

Let E be a fixed immutable quantity. E can be freely exchanged between T and V, as long as $$T + V = E$$ 1. What does the quantity $$\int_x T - V $$ signify? What is the importance of this quantity? -------------------- Let E now be the budget of a factory. E can either be spent on T or V in...

Namely, what does Perelman’s proof of it imply?

Significance of https://arxiv.org/abs/2110.00120 ,also https://arxiv.org/abs/2109.11092 on CMB anomaly and holographic models? Support?Confirmation?Interpretation? Not my field,but striking!

What is the significance of the double slit experiment? When I first learned about it I thought the human observer decided the outcome. But I guess a human observer isn't even needed and therefore a conscious mind is just as irrelevant. What does it prove that an outcome is neither one thing or...

Any practical or scientific significance of (1+1/x)^x as x->-inf?

I keep thinking that the universe "knows" when, how, where these know-it-all (no pun intended) physicists did their experiment so all the results are not only consistent, but perfectly normal, nothing freaky about it. I'm no longer capable of thinking like a normal human being and subsequently...

hi guys i would like to know what is the physical significance of the dispersion relation , i know that it relates the energy and momentum vector and correspondingly the energy and momentum with each other , but what does this tell me about the system , and why should i care that the dispersion...

I am studying Quantum physics and I'm having some problems to understand what is the Wave Amplitude since I can't find a physical significance to it. Does anyone ever heard something that come close to a physical significance?

On arXiv: The Significance Filter, the Winner's Curse and the Need to Shrink It's well known that it is difficult to publish null results in various fields. The authors try to quantify that by analyzing over a million z-scores from Medline, a database for medical publications. A very striking...

$$cos\theta = \frac {s}{1-s} = \frac{p-1}{p}$$ in this equation ##\theta## is the bond angle and ##s## and ##p## are the fractional s-character of the orbital and p-character of the orbital. This is equation is used rigorously in showing that the s-character of the axial orbitals in a ##sp^3d##...

Question: In finance, the strong form of the efficient market hypothesis states that studying financial information about stocks is a waste of time since all public and private information that might affect the stock price is already reflected in the price of the stock. However, a study of 450...

I am new to Lagrangian mechanics and I have gone through basic examples of solving the Euler Lagrange equation for simple pendulums or projectiles and things like that. But I am unable to understand what we are exactly solving the equation for or what is the significance of the differential...

If we have the wavefunction ##|ab \rangle##, what do the a and b stand for? In particular, do a and b signify an outcome of some pending or possible measurement, or do they signify some aspect of the wavefunction, and if so, which aspect?

Russia's vaccine news has me pondering. How often after a successful phase 2 study do phase 3 studies show that the vaccine causes harm? If I were offered a COVID-19 vaccine that had passed phase 2 trials, I'd accept it. Is that foolhardy of me? Is it possible to use existing data to model...

https://www.fmglobal.com/research-and-resources/tools-and-resources/resilienceindex/explore-the-data/? Below the world map, there is a horizontal graphic with dots corresponding to each country. The dots are broadly ranked from right to left according to a measure of "economic resilience", but...

Let's say the function is of a form F(x), where F(n) gives us the value of the n-th prime number, for all values of n. And it computes and discovers subsequent prime numbers directly without using any form of brute-force computation.If such a function is discovered, how ground-breaking would it...

In an Introduction to Quantum Mechanics by Griffiths (pg. 180), he claims that "P and H are compatible observables, and hence we can find a complete set of functions that are simultaneous eigenstates of both. That is to say, we can find solutions to the Schrodinger equation that are either...

Hey! :o In a study at $15$ children at the age of $10$ years the number of hours of television watching per week and the pounds above or below the ideal body weight were determined (high positive values ​​= overweight). Determine the simple linear regression equation by considering the...

I have used Laplace transform during my EE studies to solve differential equations and in control system analysis, but we were taught that as a tool kit to make the math easier. The physical meaning was never explained. I know basic time and frequency domain concepts (thanks to Fourier series)...

Taken from the Wikipedia page: Is there something significant about the physics of the Planck Particle or its properties? If so, then what is the significance? If there's nothing especially significant about the Planck Particle, then you can just say "No" and I will consider the matter closed...

Let us say that we have a dispersion relation curve and associated instability curve as shown below for a magnetised plasma, which have been formulated through kinetic theory. The frequencies and growth rate have been normalized w.r.t. cyclotron frequency of proton. My question is: what does...

Homework Statement Q1. a) In relation to Fourier analysis state the meaning and significance of 4 i) odd and even functions ii) half-wave symmetry {i.e. f(t+π)= −f(t)}. Illustrate each answer with a suitable waveform sketch. b) State by inspection (i.e. without performing any formal analysis)...

Recently I checked my IQ at Mensa iq test and got an IQ score of 128. Is there anything special about it?

If I understand it correctly, a particle doesn't have a definite momentum and a definite position, but is in a superposition of multiple positions and momenta. And when we measure either of the two quantities, say, position, the wavefunction collapses to tell us where the particle is. Now when...

Hi, when working with NS equations the stress tensor can be written as ##\nabla \tau = - \nabla P + \nabla \tau_{v}##, where ##\tau_{v} ## is \begin{pmatrix} \tau_{xx} & \tau_{xy} & \tau_{xz} \\ \tau_{xy} & \tau_{yy} & \tau_{yz} \\ \tau_{zx} & \tau_{zy} & \tau_{zz} \end{pmatrix} This...

Hi, I am confused about the electric field lines which are depicted mostly on the Internet as per conventional way. What I understand that the conventional current was due to positive charges which was wrong. Actual flow of the current was due to the negative charges or electrons. When the...

We obtain equations of motion by solving the Euler-Lagrange equations; along this path the action ##S## is an extremum. We are usually interested in the path ##x(t)## (in one dimension) connecting ##x(0)=x_0## and ##x(T)=x_1##. But does the numerical (extremal) value of the resulting action have...

Thread moved by mentor why is 'e' so important number. e^x is said to be natural language of growth. Why isn't 2^x a 100% growth.Can anyone explain me the difference between both of these and also bit more about number e which known as famous constant.please explain clearly. I will appreciate it.

Hii, As we know, Scaler triple product is volume of parallelopiped constructed by its three sides. Similary, What is the physical significance and geometrical interpretation of Vector triple product ? Also, What are the application where we use such mathematics and why ? Regards, Rahul

Homework Statement Hello! I am not sure if this is the best place to ask this question, but I need some help. So i use the bisection method to find the zeros of a function. When I do it for sin(x), with the initial interval being ##[10^6 \pi, (10^6+1) \pi]##, the program enters an infinite loop...

I am a beginner in quantum mechanics. I started out with D. J. Griffiths' book in quantum mechanics. I'm having a problem in understanding the wave function. What is the physical meaning of the wave function? I searched on the net but didn't get any good explanation. I understand that the...

A very quick question about the significance of 3: So we have 3 large dimensions. And we have 3 generations of quarks. And we have 3 generations of Leptons. Is there any known significance or reason or connection to the number 3? Are there any other examples of sets of 3 in Physics...

In a coherent state defined by |\alpha\rangle = \exp{\left(-\frac{|\alpha|^2}{2}\right)}\exp{\left(\alpha \hat{a}^\dagger\right)} |0\rangle there is a definite phase associated with the state by \alpha = |\alpha| \exp{\left(i\theta\right)} where the number operator and phase operator are...

A couple of questions today. First. I am running a panel data regression test. First I check the correlations between the independent variables and the dependent variable. these are the results. The D/(D+Em) is the dependent variable, and the independent are the 4 variables most adjacent...

Homework Statement I(λ, T) is 4 pieces multiplied: (8π/λ4) (hc/λ) (1/(ehc/λkT-1) (c/4). 1. Identify the meaning of each term. 2. Which term(s) fix the ultraviolet catastrophe? The Attempt at a Solution Well I know that the energy of a photon is given by (hc/λ), and I'm fairly certain it was...

How do i get an idea, or a 'feel' of the components of the acceleration in polar coordinates which constitute the component in the eθ direction? from what i know, a= (r¨−rθ˙^2) er + (rθ¨+ 2r˙θ˙) eθ ; (where er and eθ are unit vectors in the radial direction and the direction of increase of the...

Admins: Please excuse my E and brackets in the title, and correct if possible. My questions are these, please: 1. What is the physical significance of (\hat{a}\cdot\boldsymbol{\sigma}_{1}) in \left\langle...

Bell (1964) http://cds.cern.ch/record/111654/files/vol1p195-200_001.pdf has 3 unnumbered equations following his equation (14). Let them be (14a)-(14c). Bell then uses his equation (1) to move from (14a)-(14b). It seems to me that he uses this: [A(b,λ)]2 = 1. (X)...

In kinetic theory, the number of molecules hitting a unit area of a surface per unit time with speeds between v and v + dv and angles between \theta and \theta + d \theta is found to be a function of sin(theta) and cos(theta). There will often be a practice problem asking to show that the...

Why do we reject the null hypothesis in Goodness of fit when the Chi square statistic is less than the tabulated value of chi-square at say 5% level of significance and accept when it is more? What does it mean to have a Chi-square value more or less than the value assigned to a certain level...

Hello Physicsforums! I've stumbeld on a problem in statistics (which is one of my weaknesses when it comes to math). I´m currently trying to analyze data from a study and using multiple regression analysis. From regression analysis with one independent variable I´m used to mainly focus on the...

I was just looking at list of solar system objects and was surprised to see that the surface gravity of Uranus is only 90% that of Earth's. I get it that the "surface" of a gas planet is further from that planet's core than is the case for Earth. But does surface gravity really have any effect...

Photon energy E_p= hv=hc/lamda taking lamda= h/mc which is the electron Compton wavelength and substituting in above E_p=mc^2 L(angular momentum)=r X P=(Lamda/2)*(E_p/c)=h/2 are these results coincident or have any physical meaning, they relate a photon wavelength equal to an electron...

Homework Statement Two wires are laid side by side and carry equal currents in opposite directions. Explain why the total magnetic flux density due to the current in the wires is negligible 2. The attempt at a solution I know that having a different direction for the current results in...

Homework Statement I am working in "Intro to PDEs with Applications" on page 6. Gradients come up in discussions of surfaces expressed as F(x,y,z). In discussing such matters, the buildup includes the assumption that grad F is not equal to the zero vector. A later line reads, "Under the...

Hi, II have an issue with nodes in QM, like suppose in a well, the number of nodes depend on (n-1), the thing is that, what is so special(physically) about the point that the particle cannot be located there? Thanks is advance

I am building a business cycle index, which include 4 variables that drive the index. Each variable I also include autoregessive coefficients that are all significant and negative. I was wondering what is the significance of this? In other words, what is the significance of have autoregessive...

I have had some issues understanding this topic. On two occasions Dale has pointed out to me that they are not really based on physical things, given that their values are completely arbitrarily defined for the purpose of matching certain measurable or defined things, like the ampere and the...