Lorentz Definition and 1000 Threads

Homework Statement An electron and a positron are observed from the lab to move in opposite directions with a speed of 0.5c and 0.7c, respectively. Find the speed of the positron when observed in the electron's rest frame. Homework Equations in attached PDF The Attempt at a...

Here's a scenario: A rod shaped object 1m in diameter and 300m in length is moving through space at a velocity of .999994444429013c (picked that velocity arbitrarily for the 300:1 length contraction). The Lorentz factor is 300 for this problem. So the equation to figure length contraction is...

Are Lorentz transformations only work between inertial frames? if so, is there a simple counter-example e.g. for them not to work?

Hello, I was just going through some writings on the web reg.Lorentz transformation. Even considering the derivative factor,d, is anyway Lorentz transformation is some way, linked with Pythagoras' theorem? Correct me if I am wrong? -- Shounak

1. The question states: "Two lights are placed along the x-axis at positions x1 = 3.00 m and x2 = 5.00 m. The lights flash at times t1 = 1.00 ns and t2 = 9.00 ns. An observer in a rest frame moving to the right sees the lights flash in the same location. Assume that the origins of the two rest...

Homework Statement A particle moves such that its relativistic factor γ equals one million. Find β (=v/c). Give answer in the form β = 0.999..., with correct number of nines before first non-nine digit. Do not use a calculator Homework Equations (1-β^2)^(-1/2) = 10^6 The Attempt at...

So this is my first course in upper level physics, and I'm still trying to figure out special relativity. The problem: Two events occur at the same place in a certain inertial frame and are separated by a time interval of 4sec. What is the spatial separation between these two events in an...

Homework Statement Particle mu was created in the atmosphere and traveled 2km relative to Earth with a speed of 0.8c. Particle e was created in the same time and traveled parallel to mu with the speed of 0.6c. How much distance mu traveled relative to e? Homework Equations Lorentz...

Can anyone recommend some litterature on representations of the Lorentz group. I'm reading about the dirac equation and there the spinor representation is used, but I would very much like to get a deeper understanding on what is going on.

Homework Statement Suzanne observes 2 light pulses to be emitted from the same location, but separated in time by 3μs. Mark sees the emission of the same two pulses separated in time by by 9μs. a) How fast is Mark moving relative to Suzanne? b) According to Mark, what is the separation in...

Homework Statement The pion has an average lifetime of 26.0ns when at rest. For it to travel 10.0m, how fast must it move? Homework Equations Lorentz velocity transformation? The Attempt at a Solution I'm very lost... am I supposed to use u'x = (ux-v)/(1-vux/c2)? I thought I was following...

I thought Lorentz Transformations left Δt2-Δx2 invariant but, for example a frame moving at .5C for Δt =1 has Δx = .5 so Δt2-Δx2 = .75 If this is transformed by : to a rest frame Δt =0.65 has Δx = 0 and Δt2-Δx2≠ 0.75 not sure where I have gone wrong here, any help would be...

I am slightly confused with the invariance of four-volume element. The orthodox way to show it is to prove that Jacobian is one, that I did, however in many textbooks I find a reasoning that because we have Lorentz contraction on one hand and time dilation on the other hand, the product is...

Can anybody help me with the proof that E_p \delta ({\bf p}- {\bf q}) is a Lorentz invariant object? I did a boost along z axes and used the formula \delta (f(x)) = \frac{\delta(x-x_0)}{|f'(x_0)|} and the factor in front of the delta function indeed is invariant but within the function I...

Someone asked me how Faraday's Law of Induction and Ampere's Force Law, both which form part of Maxwell's Equations, are related. Ampere's Force Law is derived from the Lorentz Force Law. They are entirely compatible with Faraday's Law of Induction. Here's how...The Lorentz Force Law states...

London theory, Landau theory... and Lorentz Einstein law I am trying to learn all I can about superconductivity and discovered an interesting document in Internet. Does the Lorentz Einstein law hold true for the supercurrent : 1) of the London approach? js = ... ∂θ/∂r - A where θ is the...

This is a fairly trivial question I think. I'm only asking it here because after some googling I was unable to find its answer. I was at one point led to believe that the form of the Lorentz-transformation matrix is dependent on the convention used for the Minkowski metric. Specifically it...

Would it be possible for a truck, measuring 5ft tall when stationary, to pass under a 4ft barrier by accelerating towards the speed of light? If so what would a spectator see if standing next to the barrier, would the spectator see the truck shrink? What would you see of the barrier from the...

An observer on Earth observes two spacecraft moving in the same direction toward the Earth. Spacecraft A appears to have a speed of 0.50c, and spacecraft B appears to have a speed of 0.80c. What is the speed of spacecraft A measured by an observer in spacecraft B?So if S is the reference...

Iv been reading about general and special relativity and then I came across Lorentz transformation but I can't seem to find out what it is could you please help

Not sure its in the right place or not.If its not,sorry. The relativity postulate of special relativity says that all physical equations should remain invariant under lorentz transformations And that includes Lagrangian too. So it seems we have a symmetry(which is continuous),So by Noether's...

I'm quite confused on this. According to Lorentz's ether theory, he used the immobile stationary ether as an absolute frame of reference. In that case, why would the Lorentz transforms be required, since there are no relative reference frames?

I am totally confused about the Lorentz Group at the moment. According to wikipedia, the Lorentz group can be defined as the General Orthogonal Lie Group##O(1,3)##. However, the definition of the GO Lie Group that I know only works when there is a single number inside the bracket, not 2, e.g...

I have a problem understanding the Lorentz transformation of the spin. The spin 4-vector is defined in the rest frame of the particle as s^{\mu} = (0, \vec{s}) and then boosted in any other frame according to s'^{\mu} = (\gamma \vec{\beta} \cdot \vec{s}, \vec{s} +...

Is it fair to call the lorentz factor the derivative of measured time relative to proper time? I've seen the lorentz factor equated twice now to \frac{dt}{d\tau} and I wanted to know whether that was a legitimate way to look at it. Thank you

Greetings everyone(New guy here!). I wanted to know something about "Lorentz force". A magnetic force causes a loop carrying current to rotate and torque is created due to those forces. Are magnetic fields doing work in this cause? Based upon this law: F = q(E + v + B) F = I x...

Power, defined as P = dE/dt is Lorentz invariant according to http://farside.ph.utexas.edu/teaching/em/lectures/node130.html, Eq. 1645 But, considering another equation for the power, P = q E v, where E and v are electric field and velocity vectors, respectively; this is obviously not the...

Preface to my question: I can assure you this is not a homework question of any kind. I simply have a pedagogical fascination with physics outside of my own studies in school. Also, I did a quick search through the forum and could not find a question similar enough to what I want to know, so i...

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...

We know, when m=0, the schwarzschild space time becomes lorentz space time. Then, the proper time taken by one twin (A) to travel around the massive body in lorentz space while the other twin at rest can not be defined or it will be infinite. Is that true?

A charged particle - like an electron - has a magnetic moment. This moment changes depending on where the electron is. If you apply a magnetic field to an object with a magnetic moment, it experiences a torque. It turns. This turning motion is not included in the overall motion of the...

"In a Lorentz invariant theory in d dimensions a state forms an irreducible representation under the subgroups of SO(1,d-1) that leaves its momentum invariant." I want to understand that statement. I don't see how I should interpret a state as representation of a group. I have learned that...

I am a newcomer to relativity, currently studying the subject on my own, via Modern Physics by Bernstein et al. I have a question based on pgs 57-58 of the text. Suppose that two reference frames S and S' are similarly oriented, and S' is moving with constant velocity v in the positive...

Hi folks, I've been reading into the concepts of chirality & helicity and often I find a statement that chirality is Lorentz invariant in contrast to helicity (which of course depends on the frame). BUT I don't see in which way chirality IS Lorentz invariant. For massless particles things...

OK, I've found a great explanation of the derivation of the Lorentz transformation, with x' = γ [ x - v t ] t' = γ [ t - ( v / c2 ) x ] so if I take the other term as 0, there is x'( t = 0 ) = γ x t'( x = 0 ) = γ t but the problem is that the time dilation & length...

IUCSS Summer School on the Lorentz- and CPT-violating Standard Model Extension (SME) This program is going on now, at Indiana University. The title pretty much covers what the school is about. The SME simply takes the ordinary standard model and adds terms to the Lagrangian which violate...

Hello all, and thank you in advance for taking the time to read my question. To give an idea of my working level, I'm a 21 year old computer science student entering my senior year at college. It's been a few years since my Electricity/Magnetism course, and I'm a bit rusty on the Lorentz Force...

I often read sentences like, "if space is homogeneous, then the Lorentz transformation must be a linear transformation." What exactly does it mean to say that space is homogeneous, and how does it imply that the Lorentz transformations are linear?

Is it valid to analyse the equation of motion of an electron in its instantaneous rest-frame in which it feels a force from the electric field only with no magnetic Lorentz force component?

If you Lorentz transform a scalar: U^{-1}(\Lambda)\phi(x)U(\Lambda)=\phi(\Lambda^{-1}x) If you now perform another Lorentz transform, would it it look like this: U^{-1}(\Lambda')U^{-1}(\Lambda)\phi(x)U(\Lambda)U(\Lambda')=\phi(\Lambda'^{-1}\Lambda^{-1}x) ? But isn't this wrong...

Problem in Lorentz transformation(Urgent!) 1. Homework Statement Please see the attached file and advise me my solution is right or not! Thanks! 2. Homework Equations ~ d/t = v ~ Lorentz transformation : x'=(x-Vt)/(√(1-(V^2)/c^2), t' = [t-(V^2)/(c^2)]/√1-(V^2)/c^2), 3. The...

Homework Statement Please see the attached file and advise me my solution is right or not! Thanks! Homework Equations ~ d/t = v ~ Lorentz transformation : x'=(x-Vt)/(√(1-(V^2)/c^2), t' = [t-(V^2)/(c^2)]/√1-(V^2)/c^2), The Attempt at a Solution a) According to Cheryl, d/t =v...

Homework Statement Are the Lorentz transformations empirical laws? If so, are they empirically testable? Homework Equations The Attempt at a Solution I'm guessing they are. But how do you test the LT?

Hi all, I'm studying quantum field theory and I'm watching video lectures on Harward University website (Professor Colemann's lectures). Now, in lesson number six at 1h-6 minute a student asks why after trasforming field by a Lorentz transformation he doesn't transform also integration...

Essentially I'm wondering about coupling with Maxwell's equations. It seems that, for application of the Lorentz force equation to make sense, the E and B fields used should not include the E and B fields generated by the charge in question, since a charge won't exert force on itself. However...

I have been reading Lieber's book "The Einstein Theory of Relativity" which describes the derivation of the Lorentz Transformations: archive.org/details/einsteintheoryof032414mbp -- see pages 39-56 bartleby.com/173/a1.html The entire derivation makes no sense, whatsoever. Why is it...

When you rewrite the angular momentum generators Ji and boost generators Kj in terms of the linear combinations N±i=Ji±iKi, does this mean that your group parameters can now be complex? So for example a group element R can be written as: R(z_1,z_2)=\exp[i(z_1 N^+ +z_2 N^-)] where the z's...

Question on Lorentz contraction and size of "pancakes" I have read that nucleons (protons in particular) appear to look like flattened "pancakes" hitting each other due to the lorentz contraction when crashed together at high speeds. Do any of the colliders give a hint at the "size" of the...

Homework Statement Show that the Lorentz gamma factor in the decay K^+ \rightarrow l^+ \nu_l can be written as \gamma = \frac{m_K^2 + m_l^2}{2m_K m_l} where nu is either e or mu. The Attempt at a Solution I'm stuck on a part of the proof. I think I understand most of it...

Hi! In Weinberg's book "The quantum theory of fields", chapter2, it states that the transformation of a massive particle is U(\Lambda)\Psi_{p,\sigma}= N\sum\mathcal{D}^{(j)}_{\sigma',\sigma}(W)\Psi_{\Lambda p,\sigma'} where W is an element in the little-group SO(3). But than it states that...