relativity

  1. O

    Special Relativity: From an Introduction to Modern Astrophysics by Carroll and Ostlie

    1. The problem statement, all variables and given/known data Because there is no such thing as absolute simultaneity, two observers in relative motion may disagree on which of two events A and B occurred first. Suppose, however, that an observer in reference frame S measures that event A...
  2. M

    I seriously cannot do any Special Relativity Q's, humph =(

    Hi everyone. So my problem lies in that I understand the material covered, but when I attempt any questions it results in an epic fail. Could someone please lend me a hand? For example, could I post a question and have someone walk me through it please? Here goes: Q. Two spaceships A and B...
  3. J

    General relativity

    Is anyone here familiar with the mathematics (ie Einstein Field Equations) of GR. I have a question which is similar in appearance to ''space travel'' problems given in SR, however due to the acceleration involved, I'm sure a solution using the Lorentz equations of SR is flawed. On the other...
  4. M

    General & Special Relativity

    What is difference between general and special relativity?
  5. S

    Special Relativity Question

    I just started special relativity in school and, being somewhat confused, I found myself asking this question. An observer A is travelling at a substantial fraction of the speed of light relative to observer B. Since they are both moving at that speed relative to one another, how do we know...
  6. S

    Doppler phenomenon for electromagnetic waves and new equations for relativity quantum

    Author :Mohammadreza Tabatabaei Source : Doppler phenomenon for electromagnetic waves and new equations for relativity quantum
  7. J

    Spaceships! (relativity)

    1) Two spaceships are at rest with a distance x between them and tied together with a string. An observer standing in between the two spaceship sends them both a signal. As soon as the signal reaches each spaceship (same time in the observer frame) both spaceships start accelerating at a...
  8. C

    Relativity- stars and spacecraft.

    Hi, I have recently started revising for my relativity exam and don't seem to have grasped it yet. Here is a past exam Q and my attempt at it any, guidance would be greatly appreciated (particularly on part b). 1.(a.) A star is 450 light years from earth. i) what is the minimum time a...
  9. C

    Relativity- inertial frames

    Suppose the space time co-ordinates of two events in inertial frame S are as follows: Event 1: x1=x0, t1=x0/c y1=z1=0 Event 2: x2=2x0, t2= x0/2c y2=z2=0 Show that there exists an inertial frame s' in which these events occur at the same time (i.e t1'=t2') and find the value of time for...
  10. C

    Relativity, relative velocities

    Hi, could somebody please help me to answer the following Relativity question? Rocket A is travelling at 0.5c relative to an earth based observer and Rocket B travels at 0.8c Relative to rocket A. At what speed does rocket B appear to catch rocket A to an earth based observer? We are given that...
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    requirements of the prinicple of relativity

    which of these is a requirement of the principle of relativity please: a) THE PRINCIPLE OF RELATIVITY ONLY APPLIES TO FREE PARTICLES or b) THE PRINCIPLE OF RELATIVITY REQUIRES KINETIC ENERGY OF PARTICLES TO BE CONSERVED IN A COLLISION
  12. H

    Time Dilation

    I cant understand time dilation according to the theory time should be less for a moving body but according to the equation dividing factor is always less then 1 and time for moving object will be greater so can anyone help me!
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    Relativity of time length and momentum

    calculate the relativistic momentum of a helium nucleus of rest mass 6.65*10^-27 kg,,moving in the laboratory frame at o.400c.
  14. P

    relativity of time,length and momentum

    In 2000, a 20 year old astronaut left earth to explore the galaxy; her spaceship travels at 250000000 m/s. She returns in 2040. About how old will she appear to be?
  15. B

    Special Relativity

    Is to always the stationary frame of reference (on earth), and t the frame of reference moving relative to the stationary frame? this is how my teacher explained it but I went to some websites that say the contrary. And what if there is a question like "a man 6ft. tall boards a spaceship, that...
  16. O

    Relativity

    please explain me the theory of relativity(general&special).
  17. N

    Debate Relativity

    I was once a firm believer in Einstein's relativities. Now I realize they are illogical, and disproved by experiments. I sincerely want to debate this with educated people. Unfortunately, I only receive negative feedback and mockery from the scientific community. I'll try once more, but will...
  18. A

    Special Relativity

    8. A meteorite is approaching Earth head on at speed 0.40 c: A missile is fired from earth toward the meteorite to destroy it before it hits the Earth. The missile travels at speed 0.20 c relative to the Earth. (a) How fast does an unfortunate astronaut stranded on the meteorite sees the...
  19. C

    Theory of special relativity

    Because there is no such thing as absolute simultaneity, two observers in relative motion may disagree on which of two events A and B occurred first. Supposed, however, that an observer in reference frame S measures that event A occurred first and cause even B. For example, even A might be...
  20. S

    Homework questions on quantum theory (blackbody radiation)

    Hello.. i need help with two homework questions if anyone would be so kind. I do not know where to begin on solving these questions. The questions are as follows: 1. If the angular frequencies of waves in a three-dimensional box of sides L generalize to: Ω = πc/L (nx²+ny²+nz²)^1/2 Where all n...