Lorentz Definition and 1000 Threads

Today one tries to find indications for quantum gravity indirectly via low-energy effects induced by "foamy" or "discrete" structures replacing space-time at the Planck regime. It is by no means clear whether and how such discrete structures necessarily indice Lorentz symmery breaking, neither...

Given that the Lorentz force on a current when E=0 exists only at right angles to the current, such would not change the speed of the current, but only its direction. Also, when the current is parallel to a magnetic field line, no deflection of the current by the magnetic field occurs. A magnet...

Homework Statement 2 INERTIAL frames S and S': Coordinates of S: (x,y,z,t) Coordinates of S': (x',y',z',t') Whereby: x': x-ut y': y z': z t': t The point is how do you convert the coordinates of S' to the ones in Lorentz transformation. I know the formulas but I do not know...

Homework Statement Prove that the spacetime interval -(ct)^{2} + x^{2} + y^{2} + z^{2} is invariant. [/itex] Homework Equations Lorentz transformations \Deltax' = \gamma(\Deltax-u\Deltat) \Deltay' = \Deltay \Deltaz' = \Deltaz \Deltat' = \gamma(\Deltat-u\Deltax/c^{2}) The...

In his article on the Zero-point Energy: http://www.calphysics.org/zpe.html Bernard Haisch says: That the spectrum of zero-point radiation has a frequency-cubed dependence is of great significance. That is the only kind of spectrum that has the property of being Lorentz invariant. The...

Hi, a few lines below equation (3.1.5) Weinberg writes: "The transformation rule (3.1.1) is only possible for particles that for one reason or another are not interacting." I thought a lot about it, but don't see any possible reason. Can you help please? After a few lines he defines...

please let me know what is a significance of lorentz factor,and what will happen if lorentz factor is not multiplied in the time equation of lorentz transformation.

Hello, I'm studying the Lorentz group and their properties... and I have some question for them.. Peskin's text(p496) said that "we are primarily interested in Lie algebras that have finite-dimensional Hermitian representations, leading to finite-dimensional unitary representations of the...

Hi guys, this is my first post/thread, so I'd like to start with an easy one:rolleyes: I've searched the web and I wasn't able to find a satisfying proof of the fact that Lorentz contraction is NOT applied to the dimensions, that are not parallel to the direction of motion (e.g...

It is widely recognized in physics textbooks that Planck constant is a "universal constant". But I nerver see a proof. As we know, in the special theory of relativity, c is a universal constant, namely a Lorentz invariant, which is Einstein's hypothesis. But How do we know the Plack constant h...

Does anyone have the matrix form of the completely general Lorentz Transformation, with rotations AND boosts, or does it not exist?

Hi everyone, I am looking into relativity as preparation for university and I was wondering if anyone could help me out with this. I am reading Six Not-So-Easy-Pieces and in it Feynman uses the Lorentz transformation and 'derives' it, by showing that Lorentz contraction is necessary to...

Terrell Revisited: "The Invisibility of the Lorentz Contraction" I recently posted this response to a general question of how Special Relativity worked. G H Wells Jr pointed out that and [SIZE="5"]Terrell's Argument Both of these are important issues to take into account...

i am looking for a why. not a description of how to calculate or how to find its direction. i came across this question in a school question. "why does the wire move up" and then i thought. is there really a 'why'? or it just happens?

I'm slowly trying to understand sp relativity. I admit I got lost in the last thread I posted :blushing:. But thanks to all who replied! I have a question about the Lorentz transformations formulas. This is more of a mathematical question about how the formulas are derived. If you have...

I recently started self-learning special relativity. I am having lots of trouble convincing myself about the Lorentz transformations. I realize that I must be doing something really stupid, but I just can't pinpoint it. I get that the equation for x' follows from the fact that "rulers" used in...

ok - i do understand roughly what their purpose is, i think that if you have an object, a traveling at half the speed of light with constant velocity relative to another object, b which is at rest for 2 seconds, then, due to the effects of time dilation, the clock of a will slow so they actually...

Homework Statement Homework Equations http://upload.wikimedia.org/math/7/8/1/78195e8f63116bf11b2bbef574fbcc25.png The Attempt at a Solution I'm not entirely sure how to use the equations; a worked example would be very helpful!

Let's say an observer A in his rest system has a wave function for an electron double slit experiment (psi function of x and t). Would there be any inconsistencies between QM and relativity coming out of a QM analysis performed by observer A and some other observer, B, who is moving at...

Are there lorentzian transformation equations relating non-inertial frame to inertial frame. Also are there transformations relating non-inertial frame to another non-inertial frame. By 'non-inertial frame', I mean frame of reference having absolute acceleration,jerk... or any n-th order time...

Hi, I am using Griener's Relativistic Quantum Mechanics and I have a question. Using the Klien Gordon Equation (p^{\mu}p_{\mu}-m_{0}c^{2})\psi=0, he says that the transformation law for the wavefunction i.e \psi(x) transforming to \psi'(x') must have the form \psi'(x')=\lambda \psi(x) with...

Hi, Can anyone show me how to prove that the differential operator, i.e \partial_{\mu} is Lorentz covariant. In other words, \partial /\partial x'_{\nu}=\Lambda^{\nu}_{\mu}\partial /\partial x^{\mu}. And once this is done, how can I show that the D'Alembert operator...

Homework Statement Show that the electromagnetic wave equation \frac{\partial^{2}\phi}{\partial x^{2}} + \frac{\partial^{2}\phi}{\partial y^{2}} + \frac{\partial^{2}\phi}{\partial z^{2}} - \frac{1}{c^2}\frac{\partial^{2} \phi}{\partial t^2} is invariant under a Lorentz transformation...

Simple thought experiment I read and would like to hear what others think will the result will be: Let two spaceships A and B accelerate along a straight line. Observer C does not accelerate. The accelerations, as judged by C, are constant for both ships. Each ship is equipped with a...

Many equations are affected by Lorentz transformations. Time, mass, volume of a moving object, momentum, force etc. I want to know if the following equations are affected by Lorentz transformations: 1. Distance=velocity*time (r=vt) 2. E=hv 3. j*=ot 4. F=G*m1*m2/r^2 Also, is the Newton's...

It is obvious from particle accelerators that accelerating a mass increases its inertia. That should be a valid observation in all frames. But if the angle between the acceleration vector and the velocity vector is relative to the observer, then whether the mass is accelerating or...

Hi, I've been breaking my head on the matrix form of the lorentz transformation between one set of coordinates in one inertial frame (t,x^1,x^2,x^3) and what those coordinates will be in another inertial frame (t',x'^2,x'^2,x'^3). Now I understand that if have a set of coordinates in one...

Let us consider a fixed Carthesian reference frame (x y z) with a charged (+) particle locate in its origin. Moreover, let us consider two parallel conductors of infinite lenght, carrying the same current I (in the same direction y). The two conductors move at constant velocity from the origin...

hello, Please see attached Ex and its Answer. I'm surprised that the pressure Txx has the same value as that in the instantaneous frame of the rotating rod Tx'x'. I believe this could be a typo isn't it ? Isn't the Lorentz transform the following matrix for the rotating rod around the z axis...

Homework Statement We have an homogeneus electromagnetic field with E \bullet B=0 and E \neq cB Find the velocity of the reference frames in which ony E exists. Homework Equations \mathbf{E}' = \gamma \left( \mathbf{E} + \mathbf{v} \times \mathbf{B} \right ) - \left...

I am quite confusing about Lorentz factor and Bondi factor. In special relativity, the change in time of a relatively moving frame and a observer frame can be written as ∆t=∆t'/√1-v2/c2 But if we consider the world line of these 2 frames, the change in time of a relatively moving frame...

G'day, I'm just doing some physics homework and decided to attempt to prove something. This is not a homework problem, I'm just unsure how to evaluate the limit. Using the equation for transformation of velocity U=(U'+V)/(1+(VU'/c2)), I'm trying to show that if V=-c, as U' approaches c, U...

Greetings, I have been having trouble deriving the equation for the general Lorentz boost for velocity in an arbitrary direction. It seems to me that given the 1D Lorentz transformations... matrix for Lorentz transformation in x-direction, X: {{1/sqrt(1-v^2), -v/sqrt(1-v^2), 0, 0}...

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I also posted this in the homework help for introductory physics, but it wasn't getting any responses, so I guess it's slightly more advanced. Homework Statement Let L_b(a) denote the 4x4 matrix that gives a pure boost in the direction that makes an angle a with the x-axis in the xy plane...

Some time ago, I came across a nice justification (by Einstein IIRC) for the formula x'^2 + y'^2 + z'^2 - c^2t'^2 = x^2 + y^2 + z^2 - c^2t^2. The argument went something like this: (1) x'^2 + y'^2 + z'^2 - c^2t'^2 = x^2 + y^2 + z^2 - c^2t^2 = 0 for light. (2) *reasoning I forget*, therefore...

what does it mean by "any \Lambda^{\alpha}_{\beta} that can be converted to the idendity \delta^{\alpha}_{\beta} by a continuous variation of parameters must be a proper lorentz transformation"?

because it seems the Lorentz transformations constitute special relativity itself

Hello all, I am having a slight conceptual problem in rationalizing what happens when a current-carrying material is exposed to an orthogonal magnetic field. The Lorentz force experienced by the moving charged particle is generally given by (dropping directional notations for clarity): F = q(E...

Hi guys, I'm currently struggling to show something my lecturer told us in class. We have that \Psi\left(x\right) \rightarrow S\left(L\right)\Psi\left(L^{-1}x\right) under a Lorentz transform defined L = exp\left(\frac{1}{2}\Omega_{ij}M^{ij}\right) with S\left(L\right) =...

Homework Statement Hey all, my algebra isn't as great as it used to be and I am having trouble with some of the algebra dealing with Lorentz transformation. Basically, I just need someone to do a quick step by step of how to go from x' to x (see the following). I started with the top...

Hi, From what I've learned so far, Lorentz transformation meets certain criteria, such as the constancy of EM wave propagation speed in vacuum, &/ casuality, among others. My question is, why would it/would it not be applicable to phenomena that have nothing to do with EM interaction? In...

If I am at rest and I observe a train moving past me at .9c and then the train fires a projectile at .5c relative to it how fast do I observe the projectile moving? With the speeds given, the lorentz factor is 2.294. I made the incorrect assumtion that I could just take the .5c and divide it...

In elementary electromagnetics, we learned the formula of Lorentz force. While I am always confused about the origin of this formula. Because when studying electrodynamics, I always thought Maxwell equations incorporate all information we need to know about electromagnetic interaction, but I...

Homework Statement see attached .pdf. all parts of problem statement are italicized. Homework Equations see attached .pdf The Attempt at a Solution see attached .pdf Actually: my question is pretty qualitative. You can look at everything I've done with this problem so far...

Hello, Is there a way to find the lorentz factor of a point particle in a curved spacetime in terms of metric elements(diagonal) More specifically I was trying to write energy of a point particle in a curved space. thanks

This is something I feel I should know by now, but I've always been very confused about. Specifically, how does one determine what each representation of the Lorentz group corresponds to? I mean, I know that the (1/2,0) and the (0,1/2) representations correspond to right and left handed spinors...

Why the reciprocal of the damping rate in this model equal to the phonon lifetime? Can somebody give me a detailed exaplanation. Thanks.

The "v" of the Lorentz Force If I have a rotating magnetic dipole that is rotating at an accelerated rate, then it is clear that the "v" of the "B" increases around the axis of that dipole's rotation. In addition, this should affect the "v" of the "q" affected by the "B", but the force induced...

Hi, I was wondering if the spin of a particle changed under Lorentz boosts. I think what it comes down to is if S^2 commutes with the generators of Lorentz boosts (the components of S only generate the rotations of the spinor I think). I think that should be true (an electron should always be a...