Relativistic Definition and 1000 Threads

  1. G

    Proton to neutron conversion at relativistic energies

    The reaction p→n+e++νe is common inside nucleus. But it not considered when we talk about free particle and reason is simply given mass of products being larger than reactants. Now my question is if there is a high energy proton having total energy in order of 2 GeV or let it to be 100 GeV (To...
  2. moriheru

    Unraveling the Mysteries of Relativistic Strings

    My question concerns motion of relativistic Strings, as the reader with a great a mount of deductive skills can deduce :). The question is: How can I derive the P's. More acuratly speaking why is the numerator how it is. I am referring to Zwiebach chapter 6. Thanks for any clarifications and...
  3. Jonathan Scott

    Useful relativistic gravity equation of motion

    In a recent thread, I referred to what I thought was a well-known very simple way of describing how objects move in a gravitational field, in terms of the rate of change of their coordinate momentum in isotropic coordinates. It seems that this result is not widely known (and I can't see a...
  4. N

    Relativistic Orbits: Effects of Mass Increase & Length Contraction

    Suppose an observer flies through our solar system at ##v \approx c## relative to the Sun, such that he sees each planet's (and the sun's) mass as greatly increased. What happens to the orbits of the planets? Since he sees the center of mass of the solar system as flying past him at ##v \approx...
  5. Lamdbaenergy

    Practice calculations for a relativistic speed object

    Effects of a 150,000 kilogram object launched at Earth, just below the speed of light: 99.99999999999999 percent 'c' speed.The object weighing 150,000 kilograms gets a relativistic mass increase of 183,648,173,214,437,391 kilograms, therefore getting a relativistic energy of...
  6. I

    Exploring Relativistic Compression: What Happens to the Space Between Ships?

    A convoy of spatial ships leaves the Earth at a speed v. Each ship is relativistically compressed in the direction of movement. What happens to the space between the ships? Is it compressed too?
  7. freddie_mclair

    Relativistic kinetic energy derivation (from Work expended)

    Hi, I'm trying to get the relativistic kinetic energy, ## T ##, from the work expended, ## W ##, (assuming that the body is at rest initially) and I'm doing it like this (in 1D): \begin{equation} W = T = \int F ds = m \int \frac{d(\gamma u)}{dt}u dt = m\int u d(\gamma u) \end{equation} Where...
  8. Matt atkinson

    Beta+ meson, decay - Relativistic kinematics

    Homework Statement The ##B^+## meson decays through the weak interaction. One of its decay channels is . If a ##B^+## is traveling with a total energy of 9.90 GeV, calculate the range of possible energies the produced may have. (i.e. determine the minimum and maximum values of its energy.)...
  9. V

    Relativistic Uniform Accelerated Motion

    Homework Statement Hi I am supposed to calculate the distance traveled by a particle that is uniformly accelerated with acceleration equal to the Earth's gravity (i.e. a=9.81m/s^2) after 1, 10 and 100 years proper time. Homework Equations We derived in class the four vector which describes the...
  10. MiladP

    Does the weight of a relativistic mass change when measured on a moving scale?

    Consider two equal masses, m, are placed on two identical scales in a uniform gravitational field. If one of the masses moves with relativistic speed, does the moving scale read mg or γmg? Why? It seams that people used to call γm the relativistic mass where m is the rest mass. However, more...
  11. moriheru

    Boundary conditions of non relativistic strings

    I am currently reading Zwiebach and intend on reading Becker and Polchonski afterwoods. In chapter 4 he slves a partial differential equation with the Dirichlet and Neumann BC. My question is what the difference is between the two BC.(BC=Boundary conditions). Thanks for any help.
  12. S

    How Do Velocities Transform Under Lorentz Transformations?

    The question is as follows: We can define the rapidity, y, of a particle with respect to the x axis y≡tanh-1βx. Show that under a Lorentz transformation by rapidity yB y'=y-yB The Attempt at a Solution I started by working backwards (sorry if the LaTeX does not work $$...
  13. ChrisVer

    Relativistic Degrees of freedom g(T)

    Hi, I have one question, The rel. dofs are: g_* (T) = \sum_{i=bosons} g_i \Big( \frac{T_i}{T} \Big)^4 + \frac{7}{8} \sum_{j=fermions} g_j \Big( \frac{T_j}{T} \Big)^4 Before the neutrinos decoupling, the relativistic degrees of freedom are: g_*=g_\gamma + \frac{7}{8} (g_e + g_\nu)= 10.75 This...
  14. Gary Boothe

    Relativistic Effects On International Space Station (ISS)

    On the ISS, special relativity dictates the station's clocks run slower than clocks on Earth because of the high velocity, but general relativity dictates that the station's clocks run faster than clocks on Earth because of the lesser gravity. Which effect is predominant, and do the station's...
  15. Zack Davis

    Relativity: Can a Spaceship Become a Black Hole?

    Let's imagine say, a spaceship is going through space at 99% the speed of light. Relativity says (to my understanding) that as the spaceship increases in speed it's mass will increase and it shall also get slightly shorter. Let's assume that energy isn't a problem, should the spaceship continue...
  16. U

    Robertson-Poynting Effect & Relativistic Beaming

    Statement 1 - Let's assume a charged particle emitting radiation isotropically in it's rest frame, when boosted in another frame we get the relativistic beaming effect. This results in anisotropy of the radiation emitted by the charged particle in the boosted frame. Statement 2 - But a particle...
  17. M

    Solve Relativistic Momentum PROBLEM - Extra Factor of u Explained

    PROBLEM SOLVED - the worked example I was referring too was wrong :/ ---------------------------- Hello, I've been stuck on a question in one of my SR problem sets for some time now, and managed to find a worked solution to a similar problem online. I've attached an image of the problem (the...
  18. R

    Precession of relativistic orbit in pure inverse-square force

    PROBLEM: Show that Special Relativity predicts a precession of π(GMm/cl)2 radians per orbit for any elliptic orbit under a pure inverse-square force. where G is gravitational constant, M is mass of larger body, m is mass of smaller orbiting body, c is speed of light and l is angular momentum...
  19. A

    Studying Struggling with relativistic mechanics questions, need a textbook recommended

    I have never done relativity before, my uni professor isn't good enough and I can't understand a word he says, he's all over the place. Anyway I missed a week due to being sick, and I just can't catch up, I am struggling to find any textbooks that have similar notation or help me solve...
  20. S

    How do you derive relativistic tensors in an orthonormal basis?

    I have been recently trying to derive the Einstein tensor and stress energy momentum tensor for a certain traversable wormhole metric. In my multiple attempts at doing so, I used a coordinate basis. My calculations were correct, but the units of some of the elements of the stress energy momentum...
  21. moriheru

    RQM vs QM ( relativistic quantum mechanics vs quantum mechanics)

    What are the advantages of RQM against QM? If RQM is more accurate that QM then why use QM (yet only if it is) or better said if it is more complete? I read Paul Diracs lectures 1-4 and he talked about relativistic quantum mechanics and quantization of flat and curved spaces in lectures 3-4, so...
  22. I

    Relativistic mechanics Taylor expansion

    Homework Statement For a particle traveling near the speed of light, find the first non-vanishing term in the expansion of the relative difference between the speed of the particle and the speed of light, (c-v)/c, in the limit of very large momentum p>>mc. Hint: Use (mc/p) as a small parameter...
  23. ChrisVer

    Relativistic Particle Action: Minimize Length & Avoid Problems

    In case of a relativistic particle, one can try to minimize the length of the worldline of the particle, thus write the action as: S = -m \int_{s_i}^{s_f} ds = - m \int_{\tau_i}^{\tau_f} d \tau ~ \sqrt{\dot{x}^{\mu}(\tau) \dot{x}^{\nu} (\tau) \eta_{\mu \nu}} Where the minus is to ensure minima...
  24. F

    Relativistic momentum conservation

    Homework Statement Good morning/ afternoon I have a doubt about relativistic collisions, any help will be welcome. Consider the process of annihilation electron-positron to two photons. Calculate in the centre of mass system the wavelength of photons produced using momentum of e+e-...
  25. R

    Relativistic Collision: Calculating Mass, Energy & Momentum

    Homework Statement Two relativistic particles "L" and "R", each of rest mass ##m_0##, are moving at speed ##v## towards each other (in the frame of an observer). They collide squarely and are stationary afterwards. (a) From the perspective of one particle, what is the oncoming speed of the...
  26. T

    Relativistic Doppler Color Shift of White Light from Sun

    Hi, I'm trying to figure out exactly what colors a white light (i.e. the Sun) would look like to an observer traveling at varying relativistic velocities. Yes, moving away from it - red shift. Moving towards it - blue shift. In more detail, the human eye has a limited varying-amplitude...
  27. skujesco2014

    Are neutrons in a neutron star relativistic?

    As the title of the thread suggests, I'm interested in estimating the velocity distribution of neutrons in neutron star cores. Putting T ~ 10^12K gives v ~ 15%c or more under Boltzmann statistics. Could someone provide more information or a second opinion on this estimate? Thanks.
  28. Pezz

    Relativistic Conservation of Momentum Confusion

    Hey all, Simple question yet it creating a lot of confusion in me and I need some clarification. This is an example given in a book I'm reading and I just don't understand one piece of it. In the S frame a completely inelastic collision between two particles traveling at each other at speed u...
  29. LarryS

    Spinors: Relativistic vs Non-Relativistic?

    Consider the Spinor object for an electron. Are the non-relativistic and relativistic (Dirac equation) Spinor objects, from a mathematical point-of-view, identical? Thanks in advance.
  30. K

    Potential Difference: Electron Accelerated to Relativistic Speed

    Homework Statement An electron accelerated from rest through a potential difference V acquires a speed of 0.8c. Find the value of V. Homework Equations E=(gamma)mc^2, E=Vq The Attempt at a Solution For this I related the two equations above and chose a value of m=0.5MeV for the electron and...
  31. michael879

    Deriving Møller's Relativistic Minimum Radius for Rotating Bodies

    Can someone either derive or point me to a derivation of Møller's formula for the relativistic minimum radius of a rotating body? I've been searching for about an hour and it's driving me crazy! The only "minimum radius" equation I've seen imposes the speed limit c on a classical rotating body...
  32. M

    Relativistic momentum and kinetic energy

    Homework Statement What is the kinetic energy of an electron with a momentum of 40 GeV/c? The Attempt at a Solution Kinetic energy involves velocity of the particle so my first thought was to write momentum in terms of velocity. p = \frac{mv}{(1-(v/c)^2)^{1/2}} p^2 = \frac{(mv)^2}{(1 -...
  33. Ascendant78

    Why Does 1/2mγv^2 Fail to Accurately Calculate Relativistic Kinetic Energy?

    Homework Statement Show that 1/2mγv^2 does not give the correct kinetic energy. Homework Equations 1/2mγv^2 γ = 1/(sqrt(1-v^2/(c^2))) The Attempt at a Solution Well, since the classical mechanics version of kinetic energy was the integral of momentum with respect to v, I felt I could...
  34. L

    How much energy is released when 1 kg of uranium 235 is fissioned?

    Homework Statement In a nuclear reactor, each atom of uranium (235 amu) releases about 200 MeV when it fissions. What is the change in mass when 1.0 kg of uranium 235 is fissioned?Homework Equations E = mc2 The Attempt at a Solution I found the energy released per kg based on the numbers...
  35. D

    Solving Relativistic Collision using Four Momentum Vector

    1. A particle of mass M decays from rest into two particles. One particle has mass m and the other particle is massless. The momentum of the massless particle is... 2. Ei = Ef, Pi= Pf 3. This is a GRE practice problem. I can solve this problem using the old method as listed in the step 2, but I...
  36. T

    Viewing a (giant) clock at relativistic speed

    Can anyone answer this question? What you would see while watching a stationary clock that you are moving directly away from at a constant relativistic velocity? Yes, any practical clock would immediately shrink to a tiny point an instant after you passed it. So, either assume a really huge...
  37. G

    Why Can Light Only Travel at the Speed of Light?

    Pardon my elementary questions, but: Why is it that photons can only travel at the speed of light? I know because they have zero rest-mass it is only possible for them to travel at c, but is there some mathematical reasoning to this through the mass and momentum equivalence equation...
  38. P

    Relativistic Particle Decay of Higgs Boson

    Homework Statement A Higgs boson has mass 125 GeV/c2, decaying into a pair of Z bosons, mass 91 GeV/c2. In the lab frame, one of the Z bosons is at rest. Determine the kinetic energy for the other Z boson in this laboratory frame. Homework Equations E = γmc2 γ=1/√(1-β2) The Attempt at a...
  39. 7

    Has relativistic mass gone out of fashion?

    For a long time I have studied and read about whether the photon has mass. On this forum, I could find a link to a document by Gary Oas: On the abuse and use of the relativistic mass. http://arxiv.org/pdf/physics/0504110v2.pdf Oas' paper tells about an investigation done to 164 students...
  40. S

    Relativistic mechanics:circle becoming ellipse.

    Homework Statement Suppose a circle of radius 'b' is set in motion.Calculate the relativistic speed parameter β(=v/c) such that the circle is seen as an ellipse of semiminor axis 'a' and semimajor axis 'b' where a <b.3 marks. Homework Equations L=L0/γ The Attempt at a Solution...
  41. W

    Relativistic Time, Length, Mass

    Reposting to this section of the forum instead of the Introductory Physics homework section. So let's say a guy travels at 0.5c in a spaceship from planet 1 to planet 2. Am I right in saying that: proper time = time measured inside space ship proper length between planets = length the...
  42. DiracPool

    Confusion over relativistic mass equations

    I'm trying to reconcile the two relativistic mass equations and I 'm getting different results as I push the velocity towards c. In the first equation, E=mc^2/√(1-v^2/c^2), I'm getting that E approaches infinity as v approaches c. In the second equation, E=√(m^2c^4+p^2c^2), I'm getting...
  43. DiracPool

    Relativistic velocity addition

    I feel I understand relativistic velocity addition fairly well. However, the way I usually see it modeled is with two travelers moving in the same direction. Bob is in a spaceship traveling at 0.6c and shines his flashlight in the direction of travel. An inertial observer, Alice, relative to...
  44. neilparker62

    Orbital Path Length Contraction: Explained by Relativity

    Hi Just wondering about the orbital path of a high speed particle - eg electron in orbit. Is it length contracted? Then how do we manage nλ=2.π.r ? Neil
  45. T

    Do Black Holes become visible at relativistic speeds?

    Ok, so if I were to travel towards a black hole at close to c, would the event horizon become visible? Let us assume there are no stars, CMB, or any other luminous body in the universe.
  46. M

    Status of Relativistic Bohmian Mechanics: What Open Questions Remain?

    I am curious about recent progress in relativistic Bohmian mechanics. Finding a review is proving difficult (The closest I can find is a conference paper by H. Nikolic). My understanding is a set of dynamical variables are identified as "real" (beables), and their (usually deterministic)...
  47. C

    Chandrashekhar limit for relativistic fermion gas

    hi fellas, I have been working on Chandrashekhar limit, and I found a mass-radius relationship for the nonrelativistic fermi gases using this formula and i got the graph of this R=((18pi)^(2/3))/10 *H^2/(GmM^(1/3) ) (0.5/n)^(5/3) where H=(6.63*10^-34)/2pi G=6.67*10^-11 m=9.11*10^-31...
  48. ChrisVer

    Are Non-Relativistic Neutrinos Compatible with Current Particle Physics Models?

    How can someone think of the neutrinos as non relativistic? OK I understand for example that the neutrino temperature is very small even compared to their masses... but at the same time I find it non trivial to think of very light particles with energies: E≥1eV non-relativistic... How can the...
  49. A

    Derivation of relativistic momentum

    Hi all, Is it possible to derive the equation p = ymv, and hence based on this, kinetic energy formula, without referring to 4-vectors or 2-dimensional collisions, that is derive it in one dimension? I tried this website/pdf but the mathematics is beyond my understanding. So could some one...
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