Lorentz Definition and 1000 Threads

I just got to know about this concept, "Lorentz contraction". It says The size(measure) of objects decrease as we approach the speed of light(I think, I'm right!). If this is true, then the size of our sun should be slightly smaller, as the Earth races around the sun, at a speed of one-tenth of...

Hi, I am new here, but there is a question that really bugs me :-(. In Lorentz force why was the velocity defined as relative to the observer and not relative to thesystem generating the magnetic field. By defining it relativ eto the system relativity is not needed to explain how an observer...

Homework Statement A proton of mass "m" is accelerated up to a kinetic energy "K" and then collides with a stationary proton at rest. All that is left after the collision is a new particle of mass "M". (a) Write out the momentum and energy equations for the collision. (b) What is the maximum...

Lorentz Force: $$\vec{F}=q\vec{v_1}\times\vec{B}$$ v1 is the velocity of particle. And magnetic field is: $$\vec{B}=\frac{\mu_0}{4\pi}\vec{v_2}\times\frac{\hat{r}}{r^2}$$ If we combine them, we see that there are 2 velocities: v1 and v2... I just watched this video about relativity and...

If i have a current of both negative and positive charges(i know that there is also current from only negative and only positive charges,i'm not confused) along an infinite wire of square cross-section,and the we put a homogeneous magnetic field normal to the current,then a Lorentz force acts on...

The measured energy density of the vacuum has a disturbing discrepance with the one theorized by imposig Poincare invariance in QFT, usually referred to as the "vacuum catastrophe". On the other hand the Heisenberg indeterminacy principle leads to a nonzero vacuum expectation value for the...

Hi everyone! I have two questions that arose during the path integral quantization of theories involving fermions. First of all, when we prove the equivalence between the path integral formalism and the canonical quantization we make use of the eigenvalue defining equation...

Hey guys, So consider the following product of matrices: (p_{1}^{\mu}\cdot p_{1}^{\prime\nu} -(p_{1}\cdot p_{1}')\eta^{\mu\nu}+p_{1}^{\nu}p_{1}^{\prime\mu})(p_{2\mu}p_{2\nu}'-(p_{2}\cdot p_{2}')\eta_{\mu\nu}+p_{2\nu}p_{2\mu}') where eta is the Minkowski metric. I keep getting 2(p_{1}\cdot...

Hi Guys, I'm looking into the Lorentz model Since the acceleration/de-acceleration of electron can cause radiation hence create force, can anyone tell me how to modify the above equation to include the term of radiation force? Thanks. jack

Homework Statement In the inertial frame of observer A two events occur at the same position a time 10 ns apart. In the frame of the observer B moving with respect to RA, one event occurs 1m away from the other. What is the difference in time between the two events in B's frame. Solve by...

Do lorentz transformations calculate what is really happening in the primed reference frame? Or do they calculate what the non-primed reference would think the primed reference's coordinates should be? I might be doing things wrong algebraically but it seems that: If I calculate from O things...

I'm building a system that is using the Lorentz force principle, of when a wire is placed in a magnetic field(##B##) with length(##L##) and has current flowing(##I##) there is a force = ##IL \times B## that would move the wire. I want to take into account of every single thing that will happen...

Hello i have to find the Lorentz transformation for arbitrary velocity (v) relative to (O) the information's i have: 1-i have to use all 3 components of velocity ##(V_x, V_y, V_z )## 2- ##x'=\frac{x-vt}{\sqrt{1-\frac{v^2}{c^2}}}## ##y'=y## ##z'=z## 3-...

Hello, I have been wondering this for a while and have only recently thought to ask here. The Lorentz force is the interaction of a moving charge in a magnetic field, it doesn't seem to have any sort of physical force applied to it, only the magnetic interaction. I was wondering, if there is...

Prof Ramamurti Shankar has this Youtube video 'Introduction to Relativity' at And in it he derives the Lorentz Transforms something like this, at about 58 minutes into it. |------------------------- t ----------------------| time |-----ut---------------|---------- x' -------------|...

Hello, First of all, sorry if the question has been asked. I tryied to find some answers but my ignorance goes too deep for any of the previous topics I could find. I'm completely lost when it comes to the Lorentz/Pointcarré groups representations. The part that I don't understand is the...

Homework Statement Show that two measurements F1 and F2 of magnetic force at a fixed point are sufficient enough to determine B at that point as (see picture) provided v1 and v2 are orthogonal. 2. Homework Equations F = qv x B Bz = cFx/(qvy) By = cFz/(qvx) Bx = cFy/(qvz) The Attempt at a...

Homework Statement I'm reading Peskin and Schroeder to the best of my ability. Other than a few integration tricks that escaped me I made it through chapter 2 with no trouble, but the beginning of chapter three, "Lorentz Invariance in Wave Equations", has me stumped. They are going through a...

As known, any Lorentz transformation matrix ##\Lambda## must obey the relation ##\Lambda^μ{}_v####\Lambda^ρ{}_σ##gμρ=gvσ . The same holds also for the inverse metric tensor gvσ which has the same components as the metric tensor itself (don't really understand why every tex formula starts from a...

Homework Statement If two particles have velocities u and v in frame S, find their relative speed in frame S'. Homework EquationsThe Attempt at a Solution Isn't it strange that the relative speed doesn't depend on the velocity of the frame, ##\vec s##? Since the two particles have velocities...

Homework Statement Use the Lorentz Transformation equations to derive the formula relating the time period of a moving clock to that of a stationary clock Homework Equations X'=y(X-vt) Y'=Y Z'=Z t'=y(t-vx/c^2) The Attempt at a Solution t'=1/sqrt(1-(v/c)^2) . (t-vx/c^2)

I am hoping someone can help me with something. I want to go into the field of temporal physics and I was wondering if someone could help me understand why Einstein's E=mc2 isn't combined with Lorentz's factor ϒ=1/√1-(v2/c2) to further prove the light-speed barrier?

Hi all,I am trying to understand relativity and Lorentz Transformation more clearly but I have some problems. Assume that we have frame F' which is moving at velocity v with respect to F. Now assume we have an object, O, moving at velocity, w, with respect to F. Frame F has its own time, t, and...

Direct experimental evidence of time slowing down for moving clocks is well-known. With the advent of atomic clocks, round trip journeys taken by these clocks on slow moving(compared to light speed) jets show time differences with clocks that have not taken the journey. But is there...

Hello, Onhttp://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html website it says in the section "below the rocket, something strange is happening" that the distance of an object which passes the accelerating observer never increases -c2/α. I think this means, that the Rindler Horizon...

Andromeda galaxy is measured as about 2,500,000 light years from me as I am at rest with respect to the Earth. Using luminosity of known objects in Andromeda. I have a close to light speed spaceship which is pointing toward the Andromeda galaxy with a camera mounted on the nose cone. I am going...

From the diagram above, there are two types of wires a straight wire and a non-straight wire(zig-zag shaped wire), that are both placed inside a magnetic field(B), and have current flowing in both of them as well. The straight wire will experience a force and will move towards the left as...

I was wondering. For fermions someone can find that the Lorentz group is isomorphic to SU_L(2) \times SU_R(2) . However in the Standard Model there is only left-handed neutrinos interacting with the rest of matter. If Lorentz was not partially violated, wouldn't someone expect for the left and...

I'm trying to derive (14.25) in B&J QFT. This is ##U(\epsilon)A^\mu(x)U^{-1}(\epsilon) = A^\mu(x') - \epsilon^{\mu\nu}A_\nu(x') + \frac{\partial \lambda(x',\epsilon)}{\partial x'_\mu}##, where ##\lambda(x',\epsilon)## is an operator gauge function. This is all being done in the radiation...

The situation is probably well known by many of you. The setup is at rest realtive to the B-field while the rod is moving at a constant velocity. I have been thinking about the connection between the Lorentz force and Maxwell 3 and looking stuff up about it. The first question is wheither only...

When a wire( that has the flow of I) is placed inside a magnetic field(B) experiences the Lorentz force and beings to accelerate in the uniform and constant magnetic field, there is no induced EMF correct? Only when it starts to exist the magnetic field there is change in flux. And there is...

In Srednicki's text on quantum field theory, he has a chapter on quantum Lorentz invariance. He presents the commutation relations between the generators of the Lorentz group (equation 2.16) as follows: $$[M^{\mu\nu},M^{\rho\sigma}] =...

Homework Statement Given that ##x_\mu x^\mu = y_\mu y^\mu## under a Lorentz transform (##x^\mu \rightarrow y^\mu##, ##x_\mu \rightarrow y_\mu##), and that ##x^\mu \rightarrow y^\mu = \Lambda^\mu{}_\nu x^\nu##, show that ##x_\mu \rightarrow y_\mu = \Lambda_\mu{}^\nu x_\nu##. Homework Equations...

How exactly is the EM field tensor related to the proper orthochronous Lorentz group?

Hi, I am trying to understand the derivation of the Lorentz generators but I am stuck. I am reading this paper at the moment: http://arxiv.org/pdf/1103.0156.pdf I don't understand the following step in equation 15 on page 3: \omega^{\alpha}_{\beta}=g^{\alpha\mu}\omega_{\mu\beta} I don't...

Homework Statement The figure below shows the path of a particle governed by the Lorenz equations with r = 28, σ = 10, b = 8/3. The x'es and boxes show points where the path crosses the plane z = r − 2σ > 0. (a) Which indicator shows a decreasing z and which shows an increasing z? (b) Show...

My local PBS station broadcasts a physics series on a sub-channel. They call it The Mechanical Universe locally. PBS recently broadcast The Lorentz Transformation . It appears that one may view these on line, as the Lorentz Transformation began to load after I allowed it to pop-up. There are...

Homework Statement [/B] I'm trying to derive (14.25) in B&J QFT. This is ##U(\epsilon)A^\mu(x)U^{-1}(\epsilon) = A^\mu(x') - \epsilon^{\mu\nu}A_\nu(x') + \frac{\partial \lambda(x',\epsilon)}{\partial x'_\mu}##, where ##\lambda(x',\epsilon)## is an operator gauge function. This is all being...

Homework Statement A charged particle (m=1.673*10^-27 kg) exists in a region with E=10 kV/m in the x direction and B=1T in the y direction. If the particle moves without being deflected calculate its kinetic energy. Homework Equations F=Q(E+u x B) and KE=1/2 mu^2 where u is velocity. This is...

Homework Statement Hey guys! So this question should be simple apparently but I got no idea how to do it. Basically I have the following Lagrangian density \mathcal{L}=\frac{1}{2}(\partial_{\mu}\phi)(\partial^{\mu}\phi)-\frac{m}{2}\phi^{2} which should be invariant under Lorentz...

Tests of lorentz violation in space outside earth, planets, our sun, other stars, galaxies and galaxygroups have shown no violations. That is fine. But do you ladies and gentlemen, know if anyone have tested (experimental and/or theorethical) if there may happen lorentz violations (or if the...

I already know the solution to this problem, but I'm not sure exactly why it works out the way it does, so I'm looking for an explanation. Homework Statement A particle accelerator accelerates electrons at 40 GeV in a pipe 2 miles (3218.69 metres) long, but only a few cm wide. How long is the...

I'm currently taking a modern physics course, I came across this problem which really threw me off guard: Three spaceships A, B, and C are in motion as shown in the figure. The commander on ship B observes ship C approaching with a relative velocity of 0.83c. The commander also observes ship A...

Homework Statement [/B] A particle of mass m is moving in the +x-direction with speed u and has momentum p and energy E in the frame S. (a) If S' is moving at speed v, find the momentum p' and energy E' in the S' frame. (b) Note that E' \neq E and p' \neq p, but show that...

Homework Statement Anna and Bob have identical meter sticks. Anna an observer on Earth, sees Bob traveling in a spaceship at 0.5c away from her. Bob leaves his spaceship in an escape pod, moving away from Earth and the spaceship at 0.1c with respect to the spaceship. How long is Bob's meter...

Hello Physics forum, I have come here seeking for some experienced help about a doubt that to some extent is not letting me advance on my studies of electromagnetism. Basically is about the magnetic (B) field, and more specifically, about the force at each point of the vector field (The lorentz...

A quick question. It's been a long time since I had anything to do with special relativity, so I really can't remember much. But last night I was thinking about the "proof" of special relativity with the case of muons. So basically: Muons are created when particles hit the atmosphere. They...

Apriori -- before taking any of the postulates of special relativity into account -- we might say that the lorentz transformations between two frames K and K', where K' is moving w. speed v along the x-axis of K, is given by $$\vec{x}' = F(\vec x, t)$$ and $$t' = G(\vec x, t).$$ Now, i want...

Homework Statement A neutral K meson at rest decays into two pi mesons, which travel in opposite directions along the x-axis with speeds of 0.828c. If instead the K meson were moving in the positive x direction with a velocity 0.486c, what would be the velocities of the two pi mesons?Homework...

Homework Statement A traveler in a rocket of length 2d sets up a coordinate system S' with origin O' anchored at the exact middle of the rocket and the x' axis along the rocket’s length. At t' = 0 she ignites a flashbulb at O'. (a) Write down the coordinates t'_F, x'_F, and t'_B, x'_B for...