Properties Definition and 1000 Threads

Hello, I am new to this: Taking the first Pauli Matrix: σ1=[0 1 1 0] Doing the transpose it becomes: [0 1 1 0] So is it a unitary matrix? Similarly σ2= [0 -i i 0] Doing a transpose =[0 i [-i 0] Does it mean the complex conjugates are...

Hi everyone! Im developing an application with a physics library. In the application I pre-setted some materials with the following properties, Density, Friction and Restitution Im not sure if this informations are truly trustable, Can you guys just review this for me...

Hello everyone For a project I'm currently working on, I need a dc motor which can generate a torque of about 0.1-0.2 Nm (or more) with a rpm of about 120-200...

I'm having trouble finding information on polyhalogen compounds ie CsICl2 when they are dissolved in solution. I've made dichloroiodide and I'm trying to figure out why/what happened when added to HCl/NaOH/and with KI added to both acidic and basic conditions, but I don't know how to...

I have a book on Gaussian but it mainly just explains how to use the program, it only gives very brief explanations of the theory behind how Gaussian does what it does. I want to gain an understanding of how Gaussian performs the various types of calculations that it can do. I understand the...

[/itex]Homework Statement Is the following statement true or false: 'if (cn) and (dn) are bounded sequences of positive real numbers then: lim sup (cndn) = (lim sup cn)(lim sup dn)Homework Equations The Attempt at a Solution for all n in the positive reals. cn and dn are bounded. Since cn...

Hi all, I'm a part III student and taking the QFT course. The following seems "trivial" but when I went and asked the lecturer, the comment was that they too hate such nitty gritty details! The problem is page 12 of Tong's notes: http://www.damtp.cam.ac.uk/user/tong/qft/one.pdf All...

Homework Statement Describe what happens to the ionization energy, electronegativity and atomic radius as electrons occupy the next sub level. Homework Equations The Attempt at a Solution My (probably incorrect) answers: Ionization Energy: As electrons occupy the next sub level...

What are the specific properties of time in quantum mechanics? One thing I have often wondered is, Does time exist in multiple quantum states until it is measured? IE. is time an unknown variable until the act of measurement is performed by some kind of measuring device? (a sun-dial, a...

Hello, Please help in solving the four set of problems, i will be very happy explaining comment as really want to understand. The problem will spread to the extent of understanding preduduschey. 1 Problems: The set M, M = {e^(j*2*pi*k/n) , k= 0,1,2...n-1} denotes the set of the nth...

Is there a phonetic symbol that has the the three properties voiceless, glottal and fricative?

Homework Statement Prove that if 0 < a < b, then a < √ab < (a + b)/2 < b Homework Equations To prove this use the 12 properties of numbers (commutativity, trichotomy law, associativity, etc...). The Attempt at a Solution The main problem is I don't know if I need to define the...

Hello, I'm calculating a physics problem and I'm supposed to calculate the height of a building given that: rock is dropped from the building, the sound of the rock hitting the ground is heard 4.8s later, the speed of sound is 350m/s, and I don't know how do I calculate the time since...

I'm really interested in properties of the elements because it is an important philosophical question. A little while ago when I went through my chemistry textbook I wrote down all the properties I encountered. I was wondering if someone would be kind enough to point out some of the properties...

Are there any properties of commonly encountered probability distributions that cannot be effectively estimated by sampling them? Searching for "inestimable" lead to irrelevant links. Those links discussed not being able to estimate some parameters of a model when certain types of data are...

Hi everyone ! Which are the major properties of inertial forces ?

This may sound stupid, but why when I shine a laser pointer at a mirror and reflect in onto another mirror back and forth, the points of light make a parabola when the mirrors are tilted in such a way as to maximize the number of reflections happening? Tilting the mirror further or closer then...

Prove 2 ∤ 1 , assuming the existence of the natural numbers and integers along with their most basic arithmetical and ordering properties. (Not allowed to use rational numbers) 2. Let and b be integers. We say a divides b if there exists an integer k such that ka = b. 3. Well, my...

As the positron has a positive charge and is the mirror of the electron and the antiproton is negative and a mirror of the proton, will then anti-matter produce anti-gravity. If not then why not? Is this linked to the photon pairing of electron and positron?

What If there are other properties of physics we can not percieve due to a limited amount of senses. What if these are properties which are essential to the understanding of the structure of physics. Like a blind person has no way of knowing what a sunrise looks like. Where we are able to...

I don't feel I have a good understanding of what the center of mass of an object it, and what its properties are. I know it's the position of all mass elements weighted by their mass and divided by the total mass. I have learned that the center of mass moves as if it was only subject to...

I have a physics book that says the electrons orbiting an atom are responsible for the physical and chemical properties of that atom. And yet I have managed to find another source which says the number of neutrons can affect the "Density (mass/volume), boiling point, freezing point, and the...

Homework Statement This is copied from a book: $$\eqalign{ & {\rm{Time Differentitation}} \cr & {\rm{Given that: }}F(\omega ) = F\left[ {f(t)} \right] \cr & F\left[ {f'(t)} \right] = jwF(\omega ) \cr & {\rm{Proof:}} \cr & f(t) = {F^{ - 1}}\left[ {F\left( \omega \right)}...

I have a simple question about the intuition behind property 1 of a Wiener Process. It says in my textbook that the change in a variable z that follows a Wiener Process is: δz=ε\sqrt{δt} where ε is a random drawing from a \Phi(0,1) Now I think \sqrt{δt} is supposed to be the standard...

a mixture of two miscible liquids a nd b has 10 moles of a and 12 moles of b. pure vapour pressure of a is 300mm Hg and tht of b is 500mm of hg. as soon as b is added to solution A starts polymerising into an insoluble solid. after 100 minutes 0.525 moles of a solute C is added whch stops...

a mixture of two miscible liquids a nd b has 10 moles of a and 12 moles of b. pure vapour pressure of a is 300mm Hg and tht of b is 500mm of hg. as soon as b is added to solution A starts polymerising into an insoluble solid. after 100 minutes 0.525 moles of a solute C is added whch stops...

Hello everyone, I read on Wikipedia that a lot of the properties of photons are explained by them being the quanta of an abelian gauge field (link). Does anyone happen to have a good source on this? I haven't learned anything about gauge theories yet, so I'm looking for an introductory text...

I have read for the last 2 years that an electron is a particle that revolves around a nucleus. That has made me believe that an electron has only particle nature however my assumption that an electron has only particle nature has proved false. I want to know what somebody means when he says an...

hello I read about it in a book but I find anything about in the web. How is it formed and how does it behave?

Def: A low discrepancy sequence is a uniformly distributed sequence with minimal discrepancy, O(logN/N). Question: Let <x> denote the fractal part of an irrational number x. Let (<x_n>) be an arbitrary low discrepancy sequence. Is it always true that : \lim_{n \to +\infty}|<x_n - x_{n-1}> -...

Thanks to those who participated in last week's POTW! Here's this week's problem. ----- Problem: Recall that the convolution of $f$ and $g$ is defined by the integral \[(f\ast g)(t) = \int_0^{t}f(t-\tau)g(\tau)\,d\tau.\] Establish the commutative, distributive, and associative properties of...

i need the derivation of orthogonal properties of associated laguerre polynomial (with intermediate steps). someone please tell me where can i get it (for easy understanding).

Homework Statement Let V = {RXR} with addition defined as (a1,a2) + (b1,b2) = (a1 + b1, a2b2) Show the vector space condition, for each x in V there exists a y in V such that x + y = 0, fails for the V defined above. Homework Equations The Attempt at a Solution a + d = (a1,a2)...

Hi! I'm currently re-reading Griffiths introductory QM book and plan to do most of the exercises. I got stuck on one problem and had to look for some hints and found two solutions that both claim that: \int_{-\infty} ^{\infty} \frac{\partial }{\partial x}\left[ \frac{\partial \Psi...

What properties of an inductor change in a low temperature environment. Specifically in the -100 through -70 degrees Celsius range?

Does the Higgs field of a fermion exclusively attract just like a gravitational field? Or can it also have repulsion? Is the Higgs field separate from the gravitational field or is the Higgs field the cause of gravity? If the Higgs field is separate from the gravitational field, then what is its...

If I sleep on copper would there be any beneficial release of negative Ions to improve my well being. In addition, will the thermal properties of copper stabilize my body temperature at 37.5c.

hi there! If ab > 0, then (a > 0 and b > 0) or (a < 0 and b < 0). This statement I can prove, just with the basic properties of numbers! Then, 1/b is defined as b^{-1} right? So, how does one prove that if \frac{a}{b} > 0, then (a > 0 and b > 0) or (a < 0 and b < 0)? Can you give me...

Do you people know any decent and simple (no fancy math) material for the atomic physics around diamagnetism, paramagnetism and ferromagnetism? Topics like wave-particle duality, energy levels, solids, why metals are conductors, relation between magnetic moment and effective mass of...

Hello, As known, any Lorentz transformation matrix \Lambda must obey the relation \Lambda^\mu~_\nu\Lambda^\rho~_\sigma g_{\mu \rho}=g_{\nu \sigma}. The same holds also for the inverse metric tensor g^{\nu \sigma} which has the same components as the metric tensor itself (don't really...

Homework Statement http://desmond.imageshack.us/Himg228/scaled.php?server=228&filename=theorem.png&res=landing Picked up Spivak's Calculus, 3rd ed. and just started. Got to this question and I'm honestly not sure how to start, I looked in the answer book which didn't really clue me in any...

Hello colleagues! I’d like to ask your opinion on the following information. I found an article where is talking about wonderful polymer that has very interesting properties to pick up parameters when applied on some surface including human body and to register information and to transfer...

Had some questions about wave-functions. Some of the questions might be invalid due to limited knowledge of the OP. 1. Are wave-functions real? i.e. do they exist in reality? Wave-functions are mathematical/probabilistic constructs. However if they can modify/change the behavior/path of a...

Do the absorptivity, reflectivity and transmissivity of a surface depend on the wavelength of the incident light?

Hello all, I am reading a paper and there is one bit in the paper that I am having a bit of trouble understanding. Say V(a) is a convex function and then the paper has the following line: [V(-2pi + a] + V(2pi + a]] >= 2V(a) I am sure this relationship is simple and falls out somehow...

Matter (deBroglie) waves is a concept and it's existence is not confirmed (?)..that said, We know that - The de Broglie equations relate the wavelength λ to the momentum p, and frequency f to the total energy E (including its rest energy) of a particle how closely do the properties of matter...

Hi, I am reviewing some material on refraction/Huygens' principle and I would like some help with a couple of technicalities. 1) Why does light slow down when it enters a denser material? (i.e details on scattering/ microscopic effects )Are the resultant wavefronts closer together? 2) Does it...

Hey I'm reading about relativity and I stumble across statements such as if a four-vector is timelike then it's always possible to find a reference frame for which the space-components vanish. Further if a four-vector is 'four-orthogonal' to a timelike four vector it must be spacelike. I...

Good day. Can anyone tell me what the difference is the value of magnetic induction B [T] when using the normal driver coil and the coil of superconductor? Thank you.

Why are cathode rays able to penetrate very thin metal films?