Relativistic Definition and 1000 Threads

EDIT: fixed minus sign issue =) Hey, I have what is probably a rather trivial question but I just want to ensure that I'm on the right track :) If I have a wave equation of the form -\psi''(r) +A(r) \psi(r) = 0 then one can invoke (in suitable circumstances) the semi-classical...

Hi PF How does Quantum Field Theory differ from relativistic quantum mechanics? Ain't Quantum field theory just relativistic quantum mechanics or are there more to the subject? :) Thanks in advance \Schreiber

Homework Statement The Attempt at a Solution So I don't know where I am supposed to go after I right down the energy conservation equation

Looking at Lagrangians and field equations for different spin all the derivations seem to lack a common basis; they appear to lack any deep relation. Is there a unique way to understand the different forms like Klein-Gordon, Dirac, Maxwell (Yang-Mills), etc. from a common basis which is valid...

Homework Statement Two powerless rockets are on a collision course. The rockets are moving with speed v = 0.800c (rocket 1) and v = -.600c (rocket 2) and are initially 2.52 * 10^12m apart as measured by Liz, an Earth observer. Both rockets are 50m long as measured by Liz. a) What are their...

Hi, I was wondering if the formula for rotational energy: E = 1/2 * L * w where L is the angular momentum and w is the angular velocity, is actually correct for relativistic velocities. Using L = p * r and w = v / r where p = the linear momentum = m * v We get...

Homework Statement OK, so spaceship A and spaceship B are at the same location. Spaceship A sets off (instantaneously) at a speed vA\approxc, traveling in a straight line towards the finish line, which will take him a time tA. After a time \frac{tA}{2} (in spaceship B's frame of...

My questions here, in order: 1. How do Maxwell's equations demand that c is constant for everyone? People say that his equations "derive" c but I always thought that the permeability variables were experimentally derived. I fully understand the derivation of gamma from the time dilation light...

{F}=\frac {{\gamma}^3 {m} {v}^2}{{c}^2} + \gamma {m} {a} You all know this equation.Relativistic Newton's second law. The problem is as follows: As you know \gamma is dimensionless.So the first term of the right side has dimension of mass.but it should have the dimension of force! what's...

Light seems to exhibit a number of interesting phenomena when relativity is taken into account. I wanted to learn more about it; the texts I have only deal superficially with optics. Could anyone recommend a good text(s)?

In the attached file, I have formulated a simple one dimensional harmonic oscillator and solved the model numerically. Such a model might represent a simple reaction coordinate along which a liquid drop actinide nucleus might split after absorbing a neutron. Clearly the complete model involves...

Homework Statement proton hits a stationary proton which then produces a pion with the following reaction p + p = p + p +pion if the initial proton has just enough energy to produce the pion what are the speeds of the final protons and pion in the laboratory frame? m(pion)=0.144m(proton)...

Imaging a hole the whole way through the Earth, and we will drop a stone into the hole. Imaging there were no resistances at all. Now the stone would reach the opposite at the Earth and speed here would be exactly zero at the surface at the other end.. Now we will repeat the experiment...

Homework Statement protons and electrons react in the following way to make an alpha particle 4p + 2e = He + 6gamma rays + 2neutrinos the energy created by this is taken up as kinetic energy of the alpha particle, gamma rays and neutrinos. the energy of the alpha particle and gamma rays...

A particle of rest mass m_0 disintegrates into two particles of rest masses m_1 and m_2. Use conservation of relativistic energy and relativistic 3-momentum to find the energies E1 and E2 of the particles in the rest fram of the original particle. Relevant equations: E0 = E1 + E2 p0 = p1+...

I've had a good search through the archives and haven't found an answer to this question. Many apologies if this is old ground. . . Having read the threads on the Pioneer Anomaly a quick question to which I'm sure there is very simple answer (I just don't know what it is !): When...

Homework Statement A mass m travels at 1.5 x 10^8 m s^-1 and collides with another mass m at rest. The two masses fuse to become M and travel away at v_c. Find an expression for v_c using conservation of relativistic momentum and energy.Homework Equations E_a+E_b=E_c and p_a+p_b=p_c. With b at...

I think I may have asked this before, but I don't think I received a reply that made sense, at least to me. Does the gravitational force between distant galaxies become larger and more significant due to their Relativistic Mass at high relative velocities and especially at luminal and...

In the following article http://books.google.com/books?id=u1DJomI318MC&pg=PA76&lpg=PA76&dq=swallow+goldstone+particle&source=bl&ots=2JysrTHS0c&sig=Qq8r6Cw0zSVD38Vfses5BxGX9UQ&hl=en&ei=1M51Tc3hLse6hAeaxJSJBw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBMQ6AEwAA#v=onepage&q&f=false it...

The last post in the thread https://www.physicsforums.com/showthread.php?t=466305 seems to say that the relativistic force on a mass moving on a circular path is the centripetal acceleration, v*v/r, times rest mass times gamma squared. But the articles...

Last week in physics we were learning about special relativity and we got the equation p=λmv. When writing the equation the teacher also put the equations for regular momentum p=mv and regular force F=ma. I noticed that momentum is the integral of force where v is the integral of a and mass is...

Homework Statement Not really a homework, but i did run across it while attempting some questions. Was reading through the derivations of relativistic doppler effect on EM waves and was reading wiki(http://en.wikipedia.org/wiki/Relativistic_Doppler_effect" when i came across something...

Dear moderator, I would like to submit to the Independent Research forum my book "Relativistic Quantum Dynamics", which was published at the arXiv site as http://www.arxiv.org/abs/physics/0504062 The book's abstract is "This book is an attempt to build a consistent relativistic...

Steven Weinberg wrote: ''In its mature form, the idea of quantum field theory is that quantum fields are the basic ingredients of the universe, and particles are just bundles of energy and momentum of the fields.'' (see p.2 of his essay, ''What is Quantum Field Theory, and What Did We Think It...

Homework Statement A particle of unknown mass M decays into two particles of known masses m1 = 0.5 GeV/c2 and m2 = 1.0 GeV/c2, whose momenta are measured to be p1 = 2.0 GeV/c along the positive y-axis and p2 = 1.5 GeV/c along the positive x-axis. Find the unknown mass M and its speed...

If you have an object traveling at a velocity v at a point where, if the object had zero velocity, its gravitational acceleration would be a, what is the formula for calculating the relativistic correction for its acceleration at this point? Does it depend on the angle between the velocity...

Homework Statement A spaceship travels past a planet at a speed of 0.80 c as measured from the planet’s frame of reference. An observer on the planet measures the length of a moving spaceship to be 40 m. a) How long is the spaceship, according to the astronaut? b) At what speed would the...

In the derivation of the relativistic kinetic energy, K=\int_{x_1}^{x_2}F\,dx = \int_{0}^{v}\frac{d}{dt}(mv)\,dx = \int_{0}^{v}(mv\,dv+v^2\,dm) here, my lecturer told us without showing that mv\,dv+v^2\,dm = c^2\,dm Can someone please give me hints on how to combine these two integrals? I...

Homework Statement A pion at rest decays into a muon and an antineutrino. The mass of the antineutrino is zero, find the energies and momenta of the muon and antineutrino. Mass of the pion is 139.57 MeV/c^2 and the mass of the muon is 105.66 MeV/c^2 Homework Equations pion -> muon +...

Homework Statement What is the speed of an electron (me=0.511 MeV/c2) with a momentum p=5 MeV/c. Homework Equations Starting with momentum: p=\gamma mu Then solving for u: u=\pm\frac{cp}{\sqrt{c^2m^2+p^2}} The Attempt at a Solution I've never dealt with these units before (MeV/c2 and...

It is well known that the shape of soap bubbles is spherical because of the fact that a sphere is the least-area way of enclosing a given volume . If we look to a soap bubble from a frame of reference that move at relativistic speed relative to the bubbles, then ,as a result of length...

Imagine an electron in uniform motion moving at a speed near the speed of light. Pictures I've seen of the electric field around such a charge look like this one from wikipedia: The field lines are straight, but clustering around the plane perpendicular to the direction of motion...

Hey guys, I'm new here. In fact I'm new to the site. Anyway, I just need this question answered. Is it possible to skip the equations for kinetic energy by simply adding gamma to the Newtonian kinetic energy equation? If so, could you give an example?

Homework Statement A particle with mass M at rest decays into two particles, one with mass m1, and the other with mass m2. Use conservation of energy and momentum to show that: E1 = (M^2 + m1^2 - m2^2)(c^2) ________________________ 2M Homework Equations...

do you know any text or reference with extensive treatment on electromagnetic field ,potential & electromagnetic energy of point particle moving straight at relativistic velocities?

Hey guys, I am attending my second course in quantum mechanics. At the moment we are studying two-particle-systems using Dirac notation. In our book (An introduction to quantum mechanics - Griffiths) the author wrote that one can prove from relativisitic quantum mechanics that particles with...

Hello. I am trying to better understand relativistic inelastic collisions for objects with mass and the setup for them. Let's say that I have two objects with different masses, one of which collides with the other, which is stationary. Without even specifying a reference frame, can I solve...

Hi all! I'm doing a statistical mechanics class this semester where very often questions like "consider the limit of temperature going to..." pop up. Now, if you consider a relativistic system (say some gas), to what extent does it make sense to talk about temperature going to 0? [to me...

A study of the motion of a relativistic continuous medium http://www.springerlink.com/content/j8kr55831h411365/

Does anyone know of a derivation of the energy-momentum relation that does not make use of relativistic mass? In other words, a derivation that only uses invariant mass.

I'm having some problems trying to figure out how to derive relativistic momentum. The way it was explained to me, classically, p=mv=m(dx/dt),but dx/dt is measured differently in different reference frames. So, if you look at time dilation, t=ɣt' where ɣ= 1/(1-(v/c)^2)^1/2 and t' is time in the...

I just recently heard about how this small but still existent flat-Earth society believe that gravity on our supposedly flat Earth is caused by the Earth always moving upward at a constant velocity. Now obviously assuming the Earth is flat and that gravity isn't caused by mass attraction, then...

Hi, I have an assignment due in the morning, and it is complete, there is just one tiny thing I am unsure of: In a rest frame, a mass m moves west at speed v, and another mass also m moves east at speed v. Now consider the setup as viewed by an observer going west at speed u. I had to find the...

In figure 3-1 (page 63) of Taylor and Wheeler's Spacetime Physics, the observer on the train determines that the lightning strikes are not simultaneous because the flashes do not reach her simultaneously. I see two problems with this. 1. The narrative in figure 3-1 contradicts the text in...

Homework Statement \frac{dp}{dt} = \frac{d}{dt}\frac{mv}{\sqrt{1-\frac{v^2}{c^2}}} = F Find v(t) show that v -> c as t -> infinity & find the distance traveled in time t if the object starts from rest. Homework Equations The Attempt at a Solution Ive tried rearranging it into either a...

Is relativistic mass not an appropriate concept?

Hi, I can't say I've really ever done much relativity but this made me wonder. Imagine we have some frame where a muon and an electron are interacting where the electron's energy is so high that its relativistic mass can be said to be HIGHER than that of the muon in the same frame. I...

The phase of a pure momentum state for a single particle traveling freely is (p.r – Et) / h-bar. This also happens to be the Minkowski space-time dot product of the 4-momentum and the space-time 4-vector (relativistic action). Is that just a coincidence or is phase inherently...

Homework Statement I need help rearranging the relativistic momentum equation in terms of velocity. Homework Equations p = (mv)/sqrt(1-((v^2)/(c^2))) The Attempt at a Solution p = (mv)/sqrt(1-((v^2)/(c^2))) p(sqrt(1-((v^2)/(c^2)))) = mv sqrt(1-((v^2)/(c^2))) = mv/p...

Homework Statement The sigma Baryon Σ0 is at rest and decays to form an Λ0 and a ɣ photon. Homework Equations Mass of Σ0 is 1193 MeV/c^2 Mass of Λ0 is 1116 MeV/C^2 The Attempt at a Solution K obviously since the Σ0 is at rest, momentum must be conserved and the Λ0 and ɣ go...