Relativistic Definition and 1000 Threads

hello, in MTW Ex 19.1, it was considered a Weakly gravitating body whereas in Ex 19.3, a Stationary relativistic source. What relativistic means here ? does it mean the source is very dense and massive ? or does it mean it is rotating at near the speed of light ? Can I specify the mass as the...

Say I have a special type of black hole, an infinetly small one. I am standing still in deep space and i let a point mass to fall. What is it's equation of motion? I'm interested in the equation itself not just an explanation. It should be sth like this x=f(t).

I saw the following scenario on an episode of Cosmos: An interstellar spaceship accelerates at 1g for the 1st half of a journey to a distant star and then decelerates at 1g for the 2nd half. So with constant acceleration, the velocity would go beyond c at some point, which is not possible. So...

Homework Statement A particle of rest mass m0 moving at a speed of 3/4 c collides with a same-mass particle at rest and they stick together to form a composite particle. What is the rest mass of the composite particle and what is its speed? Homework Equations E = \gamma mc^2 p = \gamma mu...

Hello All, I was recently looking into explanations for the operation of Faraday's unipolar generator and came across the following article, titled "The Unipolar Generator, A Demonstration of Special Relativity" published by a professor at the University of Maryland...

So there have been some theoretical designs for ships in the past that would be used for interstellar missions, i.e. Daedalus, Ramjet, Orion, etc. that may send ships to near relativistic speeds. I think daedalus had a max. speed goal of around .1c. My question is do you think that...

Homework Statement (see attachment) The proton charge is ##1.6 \times 10^{-19} C## and the speed of light is ##3 \times 10^8 m/s##. The proton's mass is not necessary in this problem. Homework Equations The Attempt at a Solution The particle revolves in a circular path, hence...

Imagine you're standing on a long, straight and smooth road. You place a block on the road. The normal reaction force acting on the block is equal to its weight. Then you give the block a little push. Since the block is moving from your frame, its relativistic mass increases. Will its...

Homework Statement The K0 meson is an uncharged member of the particle "zoo" that decays into two charged pions according to K0 ---> π+ + π-. The pions have opposite charges as indicated, and the same mass, mπ=140MeV/c^2. Suppose that a K0 at rest decays into two pions in a bubble chamber in...

Homework Statement A 3.000 u (1 u = 931.5 MeV/c2) object moving to the right through a laboratory at 0.8c collides with a 4.000 u object moving to the left through the laboratory at 0.6c. Afterward there are two objects, one of which is a 6.000 u object at rest. A) Determine the mass and...

Homework Statement A light source moves away from an observer at a speed vs that is small compared to c. show that the fractional shift in the observed wavelength can be approximated by \frac{\Delta \lambda}{\lambda} \approx \frac{v_2 }{c} Homework Equations f' = \frac{\sqrt{1+ \frac{v}{c} }...

Hi, I've been wondering about this forever and I finally decided to ask on the forums. In relativistic index notation (with c= \hbar =1) with the minkowski metric g\mu\nu=diag(1,-1,-1,-1), the 4-vector x^{\mu}=(t,x,y,z)=(x^0,\vec{x}), and with the del operator defined as \partial_{\mu}\equiv...

Homework Statement a Pion traveling at 0.93c decays into a muon which travels in the same direction and a neutrino which travels in the opposite direction. Use conservation of energy and momentum to find the energy of the muon as determined in the rest frame of the original pion. You should...

How can we restrict the RMS speed of molecules to comply with relativity? They obviously can't go at or faster than the speed of light. If you are dealing with particles inside of very hot stars for example you may get very high erroneous speeds. v = \sqrt{\frac{3KT}{m}} How could...

I'm trying to understand exactly why Einstein considered Maxwell's electrodynamics to be non-relativistic. As I read Maxwell's paper, it seems to me that it is concerned only with relative motions. I'm thinking that the problem must be with the stationary ether proposed by Lorentz, for then...

Homework Statement a D meson is at rest and decays into a Kaon and a Pion. The Kaon moves with speed 0.867c and has a mass of 0.494 GeV/C^2. The pion has a mass of 0.140 GeV/C^2. use conservation of momentum to calculate the speed of the Pion. Homework Equations Relativistic Momentum P =...

Here is a thought experiment on Special Relativity involving charges which are rest with respect to each other. Consider a configuration of charges as shown in the image. Four identical charges (q) are placed at the corners of a square with an opposite charge at the centre (Q). The value of...

Homework Statement In this thread the author performs the following calculation under "method 1": v+dv=\frac{v+dv'}{1+vdv'}=v+(1-v^2)dv'\implies dv'=\frac{dv}{1-v^2} He's set c=1 so the second expression is the relativistic velocity addition formula. What I don't understand is how he gets the...

Homework Statement In an electron positron collider, an electron and a positron are collided such that their momenta in the lab are equal and opposite. In such a collision, the electron and the positron annihilate and produce a muon and an antimuon. The rest mass of a muon is 106MeV/c^2...

Given the formula \vec{p}=\frac{m_0}{\sqrt{1-\frac{|\vec{v}|^2}{c^2}}}\vec{v}, I'd like to make \vec{v} the subject, so I can do a numerical approximation for some relativistic motion problem. I want to treat it as a vector equation, but since it is non-linear, the only way I can think of is to...

Homework Statement Particle track detectors are used to measure the speed of particles if the lifetime of the particle is known. Particle X has a lifetime of 256.2 ps. These particles are created in an experiment inside the detector by a given reaction. The particles leave 21.8 cm long...

Hey again, I have a question on a couple of things related to feynman diagrams but also the relativistic scalar propagator term. First of all, this interaction: The cross represents a self-interaction via the mass and characterised by the term: -im^2, is this just some initial state...

Okay so in a HDM scenario, I have seen it described that the neutrinos were relativistic at freeze out. (If I could find it I would reference it.) Is this a contradictory statement? The condition for relativistic travel is E>>m but just before freezeout, the neutrino has energy equal to...

Hi all, Does someone know where to find the relativistic generalization of the larmor formula? I'm interested in the integral that involves a lot of dot products. So not the derivation that uses covariance to arrive at the formula. Are there any articles or books available that work out...

So I understand the basics of the general and special relativistic effects on the speed of the satellite clocks onboard the GPS satellites, and why they are rigged to calculate time slower than an atomic clock at sea level. But then, in several articles, I read that GPS receivers are also...

I have been trying to derive why relativistic momentum is defined as ##p=\gamma mv##. I set up a collision between 2 same balls (##m_1 = m_2 = m##). Before the collision these two balls travel one towards another in ##x## direction with velocities ##{v_1}_x = (-{v_2}_x) = v##. After the...

I was reading the Wikipedia page on "Mass in Special Relativity" (http://en.wikipedia.org/wiki/Mass_in_special_relativity) and I came across two equations: M = m/sqrt(1-v2/c2) and p = mv/sqrt(1-v2/c2) along with the following quote: Einstein's comment seems to suggest that the...

Imagine a microwave oven on some kind of track such that it can reach speeds approaching c. If the microwave was switched on and shot past us at a speed so that as it traveled away from us, the relativistic doppler effect shifted the emitted microwaves into the visible spectrum - What would we...

What is the correct equation for relativistic kinetic energy? Is it KE=mγc^2-mc^2 or KE=mc^2(γ-1)?

Here's a clip from the educational series The Mechanical Universe. http://www.youtube.com/watch?v=S24MNqi18l8&t=9m5s Watch till the part where they "warp" a Minkowski diagram. In the spectator's frame, it seems as though both Einstein and Lorentz have relative velocities from 0.6c...

Why is there an inherent presumption imbedded in the field of physics that gravitational force is exempt from the rules of relativity? The presumption is based on the non-relativistic expression for escape velocity: v=(2MG/r)^.5 Thus, with a very large mass or a very small radius...

Hi, 1) How does the electric circuit variables such as Voltage, Electric current, and Resistance vary between two frame of references? 2) Based on (1): If someday we build a spaceship that move with very high speeds, are there issues to consider regarding the electric circuits in the ship?

Hi. I'm reading some quantum field theory and I'm a bit rusty in my relativistic kinematics. I stumbled across the formula E_1E_2 v_{rel} = ((p_1p_2)^2 - m_1^2m_2^2)^{1/2} where 1 and 2 are two collinearly colliding paritcles with their respective masses and v_{rel} are their relative...

Hello, first time poster here! I am trying to understand some results I am getting from this "Relativistic Star Ship Calculator". This site sets up the question I'm trying to answer exactly like I imagined it should (thanks to The Forever War). From the description: The star ship...

While I was looking up E=mc^{2}, I have learned such formula only applies to stationary objects and for kinetic object, the formula is this: E_{r}=\sqrt{(m_{0}c^{2})^{2}+(pc)^{2}} Where E_{r} is relativistic energy and m_{0} is rest mass In the formula, what is p and what is (pc)^{2}...

Hello, I've just registered to ask this question. This is something that's been bothering me for some time. I have a non-elastic collision of 2 masses in 1-dimension observed by two different frames of reference, and the total momentum of the system is conserved for one of them but not for the...

Question about the a "relativistic rocket" Intro: If one was to measure the redshifts and distances of all galaxies around earth, they would come to a conclusion that they were in the center of the universe because all the galaxies are "moving away from them" faster as the distance to them...

Homework Statement At the radius of the Earth’s orbit around the sun (1.5 *10^13cm = 1AU), the flux of radiation from the sun is 10^6 erg/ cm^2·sec . Now consider a spherical dust grain of radius r with internal density \rho = 2g/cm^3, at some distance R from the sun. Assume that the...

I need to elaborate the equation ,and need to know what is the physical significance and how matrices will manipulate in the equation $$ \hat{H} = (\hat{\tau_3}+i\hat{\tau_2})\frac{\hat{p}^2}{2m_0}+ \hat{\tau_3}m_0 c^2 = \frac{\hat{p}^2}{2m_0} \left| \begin{array}{ccc} 1 & 1 \\ -1 &...

My textbook explains relativity with the help of relativistic mass... My questions are- 1. Does relativistic mass has any effect in gravity? I mean do the object with more velocity attract things stronger than before? 2. I will see the object which going at a high velocity (from my reference...

A sphere with the radius of 4 kilometers and a mass of 2 suns moves to observer at the speed of 0.866c. From sphere frame of reference it's mass is 1 sun's mass, radius 4 kilometers and velocity 0. Can light escape from such object? Does escaping is also relative? How about direction of light...

Let’s say there was a stable Acceleration Due to gravity at 1m/s^2 towards a certain direction, and a stone would keep accelerating that direction. The Stone wood not reaches the speed of light, because it requires more and more energy to reach a diminishing speed increment. How fast would...

Homework Statement Show that 1/\sqrt{1-(u'/c)^2}=\gamma(1-(vu/c^2)/\sqrt{1-(u/c)^2}Homework Equations The Attempt at a Solution Since I'm terrible with Latex I took a picture of what I have so far. I'm not sure where to go next or if I'm even on the right track. My professor gave a hint...

Homework Statement Two trains leave a station, one going westbound and one going eastbound, both on the same track. A passenger who just wanted to get out of town missed both trains and, while standing on the platform at the edge of the track, observes the westbound train to be receding at 0.6c...

In thermodynamics (ignoring relativistic effects) you can use the maxwell-boltzmann-distribution to find the average speed of the gas particles. v^2=\frac{8kT}{\pi m} But there are high Temperatures that would have average speeds > c. Are there distributions that describe gases with an...

Homework Statement You fire a light signal at 60° north of west. (a) find the velocity components of this signal according to an observer moving eastward relative to you at 0.5c. From them, determine the magnitude and direction of light signal's velocity according to the other observer. (b)...

To my understanding the Relativistic Doppler shift is a product of the classical velocity shift and the dilation factor arising from that velocity. The classical effect can be red or blue depending on whether the emitter and receiver are receding or closing respectively. The dilation...

A spaceship with an arbitrarily large quantity of fuel cells departs Earth and accelerates away from it with a fixed trajectory until it reaches .9c. It continues to accelerate, but never reaches c because that is impossible for any object with mass. From the frame of reference of the crew...

Hi, A proton initially at rest finds itself in a region of uniform electric field of magnitude 5.0 x 106 Vm-1. The electric field accelerates the proton for a distance of 1 km. Find the kinetic energy of the proton. So, what I did was the following: KE = q * E * s I then...

Hello guys, The question is: What is the momentum, in conventional SI units, of a proton of momentum 685 MeVc-1? So, I tried two methods which yielded slightly different answers, both proximate to the actual answer (3.66 x 10-19)What I first tried to do was to rearrange: ρ=γm0v To find the...