Fields Definition and 1000 Threads

Let me give you an example of a reasoning I made in a simple case. Afterwards comes the question: Start of reasoning. Consider two standard ideal capacitor plates with a dielectric material in between them. Let's call the external field caused by the plates ##\vec{E_{ext}}## and the average...

Good day everyone! n00bie here. I did do a search before I posted this... found a lot of info, most of which I couldn't apply to what I am doing (because I wouldn't know how). I have something that I am working on that creates an electric field to alter certain chemical compounds. The distance...

I was wondering. What's the reason for putting objects in low representations in the SM and not higher ones? So, why fermions in a doublet of SU(2) and not a multiplet? In analogy in SU(5) we put the particles in the 5-plet...

Is magnetic field conservative or non- conservative field? I think that it should be conservative but not sure.

I have some questions with regards to conjugate points on a congruence of time-like geodesics (will be referring to Wald 9.3 throughout). First, we define ##\gamma## to be a time-like geodesic with tangent ##\xi^a## parametrized by ##\tau## and with ##p\in\gamma##. We consider the "congruence of...

I hope this isn't deleted for "personal theory" reasons because it's really just a discussion point. I just have to give two paragraphs of preamble before getting to the point. To me, an oversaturated field is one in which there are too many qualified people for the number of quality jobs...

Hey guys; I'm looking for info on the maximum power transfer using the magnetic induction method. The current through a coil, then catch the mag field with another coil idea. Mainly looking for high energy transfer methods, maybe some equations that describe it. A friend and i are playing...

Imagine you have an electron traveling at high speeds... would you expect it´s EM field to be contracted following the Lorentz transformations?? If the answer is no, please explain why fields and their shape don´t deform when space-time does. How they retain their shape in a space that is not...

In electrostatics, ∇ × E = 0 so E that is a conservative field and there must be sources of E from which E flows. We know that this sources are the electrical charges given by Gauss' Law. But when B changes in time, ∇ × E = - ∂ B / ∂t. Now the Gauss' Law no longer applies and if there are not...

I was reading about the Klein Gordon equation of scalar fields. I notice that the hamiltonian is not Hermitian: ∂0(Φ,π)T = matrix((0,1),(-p2,0)) (Φ,π)T The Hamiltonian operator iH = matrix((0,1),(-p2,0)) is not a hermitian matrix. What does this mean? Does this mean Klein Gordon fields don't...

I read in an article that a quantum field is one where every point in the field is defined by an imaginary number. If you square the imaginary number you get a wave function. But can a three dimensional field be defined by a set of points, finite or infinite? Does it mean a field characterized...

Homework Statement A cathode-ray tube aims electrons parallel to a nearby wire that carries current in the same direction. What will happen to the cathode rays in terms of deflection? The Attempt at a Solution [/B]The Motor force deflects the cathode rays ?

Let's say there's a question where there are two charges placed, and a point in between and above the line connecting the two charges forms a triangle like this: http://session.masteringphysics.com/problemAsset/1413940/2/p19.5.jpg What would one have to do in order to find the electric field...

Homework Statement Two parallel conductors each carry 10 A of current in the same direction. a) What is the magnetic field strength at the midpoint between these wires? (answer = 0T) b) What is the field strength at the same point if the current ran in opposite directions? (answer = 4.0x10^-4T)...

Homework Statement Demonstrate the equivalence between the gauge fields A1=(0,bx,0) and A2=)-yB/2,xB/2,0) and find the scalar field Φ for which A1= A2 + ∇ΦHomework Equations B = ∇XA The Attempt at a Solution The first part is fine, you just plug it into the above relevant equation and you get...

If we consider E and B individually, there are 6 total degrees of freedom. But they are actually related to each other by Maxwell's equations. So we can find potentials and reduce dof to 4; 3 in vector potential and 1 in scalar potential. Thus, there remain 2 redundant dof. This is the...

Hi, Am I correct in thinking that for a positively charged spherical electrode, the charge is distributed radially from the entire surface of the sphere, and as such, the electric field is distributed in this way too? If an earthed electrode is then placed nearby, a high voltage would be...

In http://arxiv.org/abs/hep-th/9506035 the author said after writing this equation: $$\frac{1}{4}\eta^{\mu\nu\lambda\rho} F_{\mu\nu}F_{\lambda\rho} = \eta_{\sigma\tau\alpha\beta}\frac{\partial L}{\partial F_{\sigma\tau}} \frac{\partial L}{\partial F_{\alpha\beta} } + 2C$$ where C was arbitrary...

Hi If anyone has job prospect info, statistics or anything about these, please tell. Thanks a lot Energy and Fluid Systems Manufacturing and Dynamic Systems Materials Engineering

Hello! I hope I posted this in the right section. I have tried to google the definitions of what follows but I didn't get what I expected. I would like to ask you then: What is the definition of a self-dual field and a self-dual topologically massive vector gauge field? Thank you very much...

When a moving proton travels through a magnetic field, doe's it's magnetic field (that it's giving off) naturally align with the outside magnetic field (due to a magnet or something in the environment)?

I am a senior physics BS student, applying to programs in condensed matter and high energy physics at the moment. However, I have always been interested in doing an MS in EE. Its sort of late this year though, and I can't apply for EE programs now. But that got me thinking: is it possible to...

In the Einstein-Hilbert action wikipedia page, the following paragraph is written: I thought for treating spin, we need to consider Einstein-Cartan theory! This is really surprising to me. Can anyone suggest a paper or book that explains this in some detail? Thanks

Hey! :o I have to show that $\mathbb{F}_{2^2}=\mathbb{Z}_2(a)$, where $a \in \mathbb{F}_{2^2}$ is of degree $2$ over $\mathbb{Z}_2$. Could you give me some hints how I could show that?? (Wondering)

Is a one-dimensional gravitational field possible? I'm not sure if I'm using the correct terminology, what I mean is instead of pulling things into its center of gravity it pulls things in the same linear direction until it ejects it out.

Over seven years ago, I was homeless for a period of time. During this time, i was arrested twice and convicted twice for theft under $500 dollars. In both instances I only stole food to feed myself (although I don't believe it matters, as I imagine it isn't reflected on the record). Since then...

Say I have a large spacetime lattice set up on a supercomputer where I calculate the scattering cross section of two spinless electrons of equal and opposite momentum via lattice QED. To get the right results we must add the amplitudes for every possible "path" the field can evolve from initial...

Hello! (Wave)I have to check if the equation $3x^2+5y^2-7z^2=0$ has a non-trivial solution in $\mathbb{Q}$. If it has, I have to find at least one. If it doesn't have, I have to find at which p-adic fields it has no rational solution.Theorem: We suppose that $a,b,c \in \mathbb{Z}...

The Faraday paradox is a hard one to get ones head around and I was wondering if there is a similar scenario, involving an E field where there is / or is not an induced emf?

Discharging a capacitor through an inductor creates oscillations. This is about as much as I understand about it. I'm having a hard time explaining my question so I attached a pic. My questions: 1. In circuit A, are there oscillations in the inductor as the battery charges the first capacitor...

I am 15 and in high school and recently there has been a big push in our school system to decide on your career now. For the past 7 years I have had it in my mind to become a nuclear physicist. Now, however, I can not decide on what physics field to go into. I can not choose between nuclear...

Hello! (Wave) Given the following two lists: what could we do, so that the first list contains both the elements of the first and the second list, sorted? (Thinking) I wrote the following algorithm: pointer *P=L1, *Q=L2,n; while ((P != '\0') && ( Q != '\0')){...

So there was this article published today that some researchers may have found a dark matter signature emanating from the sun in the form of xr-ray emission from axion interactions with Earth's magnetic field. Article...

If a question asks for the direction of the maximum gradient of a scalar field, is it acceptable to just use del(x) as the answer or is the question asking for a unit vector? Thanks

How would you generate extreme electric fields between two small surface area parallel plates.

If we consider a current carrying conductor, every instant an electron enters the conductor, another electron will be leaving the conductor. Thus, the current carrying conductor will not be charged (i.e, it would not have any net positive or negative charge). Remember dipole has zero net charge...

Dear all! I think the main difference between scalar and vector fields is that vectorial fields are composed of vector elements that varies among them. Scalar fields are fields that have large regions of equal magnitude, variations are just presented in different regions. Please bring me help...

Homework Statement a. Calculate the energy density of the electric field at a distance r from an electron (presumed to be a particle) at rest. b. Assume now that the electron is not a point but a sphere of radius R over whose surface the electron charge is uniformly distributed. Determine the...

I'm limiting my question to this field because it is the only one I know of with a certain degree of knowledge. I doubt they really exist because of the following reasoning: Coulombs law was stated because it makes mathematical sense (think of "force directly proportional to the charges and...

The time I will be asked to take a subject for my graduation project and I'm searching for something in hot fields for modern physics research. Unfortunately I don't know where to look and I was hoping for some help. Any suggestion would be much appreciated. Thank you in advance.

Hello PF, I am having a bit of difficulty understanding this question. Homework Statement "A thin wire with linear charge density λ is surrounded by a conducting cylindrical shell." (There is a hollow cylinder with a wire though it) "If the electric field must be zero inside a conductor, is...

Quantum field theory deals with the quantization of the electro-magnetic field, and finds its quantum: the photon. Electric and magnetic fields are classical fields. Can QFT quantize also them, and find their quanta? It is often said the electrons are field quanta (particles are quanta)...

One argument against Mach's principle is the speed of light restriction. How could the distant cosmic mass of the universe instantaneously have a local effect on an accelerating mass? But could we view this from the perspective of a field that is already presently locally at all points in...

Hi All, I am going over a definition of a Contact Vector Field defined on a 3-manifold: this is defined as " a vector field v whose flow preserves the contact structure " . 1) Background (sorry if this is too simple) A contact structure ## \xi ##( let's stick to 3-manifolds for now ) is a...

Hello. I'm looking to build a strong electro magnet with ac power. I was going to use a MOT transformer so the primary was going to be the same windings. For the secondary windings though I'm trying to decide if I want to go with a higher current or voltage. I would assume that a stronger...

Homework Statement A plastic rod of finite length carries an uniform linear charge Q = -5 μC along the x-axis with the left edge of the rod at the origin (0,0) and its right edge at (8,0) m. All distances are measured in meters. Determine the magnitude and direction of the net electric...

Two electrons, they have their electric fields and magnetic dipole moments. Their electric field is proportional to 1/r^2, and electric force is also proportional to 1/r^2. http://en.wikipedia.org/wiki/Magnetic_dipole%E2%80%93dipole_interaction However, their magnetic dipole field is...

So, as i understand, the geometrical meaning of this type of integral should still be the area under the curve, however, I really do not see how you can obtain each infinitesimal rectangle from the dot product. I have understood the typical work example, that is, the line integral as the sum...

Do gauge fields work the same way as the Higgs field? Are gauge fields all encompassing too, like the Higgs field? What are the differences between the functioning of gauge fields and Higgs field?

I know that a magnetic field will have an electric field bc there is charges, and they are moving. Thanks physicsforums!