# Special & General Relativity

- Dependence of various physical phenomena on relative motion of the observer and the observed objects. Exp. & theo. theories of relativity
 Meta Thread / Thread Starter Last Post Replies Views Views: 113,957 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Before posting anything, please review the Physics Forums Global Guidelines. If you are seeking help with a... Feb23-13 08:40 AM ZapperZ 1 41,486 The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many... Dec31-07 02:06 AM jtbell 0 41,112 Einstein's article "on the electrodynamics of moving bodies", starts with talking about synchronizing clocks at... Mar4-14 11:46 AM WannabeNewton 7 381 I've been working on Ex 5.4 in MTW. The maths is fairly straight forward, but I don't really understand what is going... Mar4-14 09:40 AM TerryW 2 359 Hi all. I'm taking a course in GR and trying to get my intuition and mathematical techniques up to speed. I've been... Mar3-14 03:42 PM PAllen 6 438 In GR one of the fundamental postulates is that ##-ds^2 = - g_{\mu \nu} dx^\mu dx^\nu## is interpreted as a the time... Mar3-14 10:27 AM dauto 1 281 Hi folks! I'll start by admiting that I'm a cockroach compared to Einstein or Hawking, and I think that due to... Mar3-14 10:24 AM dauto 14 572 It seems that time dilation does not occur due to acceleration alone. It surprised me to learn this due to the... Mar2-14 12:55 PM PAllen 19 862 I know that the spacetime in special relativity is not curved and that the axis can be transformed via the lorentz... Mar2-14 10:52 AM Naty1 2 324 Hi, I have been pondering on this - what is the energy required to move a point mass m0 from a radial position... Mar2-14 08:39 AM Sunfire 11 563 Hey guys, I am working on a computer simulation of our solar system and basically analyzing the affects of the... Mar1-14 04:18 PM muzz 0 274 Suppose Alcubierre warp drives or some alternative form of warp drive is possible. Then surely a warp drive could... Mar1-14 01:59 PM PAllen 3 513 I was wondering how is our perception created according to relativity, since what we perceive depends on the... Mar1-14 11:07 AM Nugatory 7 579 Hello All, As far as the Newtonian mechanics and Einstein's GR is concerned, I am a little bit confused in the... Mar1-14 09:44 AM Naty1 55 2,578 When we write contravariant and covariant indices, for example for the Lorentz transformation, does it matter if we... Mar1-14 04:06 AM Fredrik 2 365 Hi. I'm curious about this: The supposed "warp drive" by Miguel Alcubierre is supposed to go faster than light.... Feb28-14 10:11 PM UltrafastPED 2 359 In a Kerr Black Hole there exists a region called the Ergosphere. It is between the Event Horizon and a spheriod... Feb28-14 02:25 PM Philosophaie 2 315 I'm only an amateur enthusiast when it comes to physics and have no background in science at all. It's just something... Feb28-14 11:17 AM phyti 35 1,373 So I read the Wiki entry, and from what i gather ultrarelativitic speeds are speeds that almost the speed of light (I... Feb28-14 09:31 AM jtbell 8 397 Bit confused regarding how non-inertial frames can be treated in GR (and by non-inertial i mean affected by some kind... Feb28-14 01:58 AM WannabeNewton 1 288 I am trying to write the Einstein field equations $$R_{\mu\nu}-\frac{1}{2}g_{\mu\nu} R=\frac{8\pi G}{c^4}T_{\mu\nu}$$... Feb27-14 10:56 PM Nabigh R 2 467 There is a moving light clock at a certain velocity. For an outside observer, the light just seemed to be traveling in... Feb27-14 07:04 PM DaleSpam 28 1,061 If we consider a perfect relativistic fluid it has energy momentum tensor T^{\mu \nu} = (\rho + p) U^\mu U^\nu +... Feb27-14 05:53 PM TrickyDicky 15 485 The solution of Einstein's field equations for a simple black hole show a slowing of time as you get close to the... Feb27-14 11:44 AM PAllen 37 2,077 Hi guys, Firstly apologies if this question has been asked before (or are stupid questions) or better explained... Feb27-14 08:58 AM jtbell 5 561 This is a purely terminological question. Consider the following setup: we have two inertial observers A and B at rest... Feb26-14 04:28 PM bcrowell 14 971 Hello To demonstrate that we can deduce from special relativity the existence of an observer who finds that his... Feb26-14 01:26 PM DaleSpam 54 2,182 I recently watched a video in Einstein's train though experiment. www.youtube.com/watch?v=wteiuxyqtoM From what... Feb26-14 11:29 AM Yashbhatt 17 727 Suppose we have an event horizon H which is a light-like, closed 2-surface. Photons radiated outwards at the horizon... Feb25-14 09:41 PM George Jones 3 340 Trying to understand the conservation of relativistic momentum, I thought of this problem. It's very simple, and... Feb25-14 03:55 PM epovo 2 287 I was just reading the sci.physics.faq http://math.ucr.edu/home/baez/physics/Relativity/SR/rigid_disk.html on the... Feb25-14 02:46 PM bcrowell 15 497 Hi all, I tried searching for this but failed to find an answer to my question. I am having an issue with properly... Feb25-14 01:01 PM scinoob 12 797 Howdy, This is my first post. Please be gentle. ;-) I have been thinking about the speed of light. Scenario... Feb25-14 09:19 AM dauto 4 451 Sorry I'm new to this. There are apparently four forces in the universe: Gravity, EM, Weak and Strong. Is gravity... Feb24-14 04:19 PM pervect 7 638 hi guys i have question can any body answer please. why the light fell in to the black hole whether it have no mass. Feb24-14 02:43 AM mra20x 3 334 Could spacetime itself be a field? Feb24-14 12:01 AM Fredrik 5 324 i have asked my physics and maths teacher a question which they could not answer, the question follows:- Does the... Feb23-14 06:30 PM pervect 15 796 I'm working through A. Zee's new EGR book, and I came to a step on tidal forces I couldn't follow. He presents the... Feb23-14 10:33 AM russelljbarry15 4 526 Is there an absolute sequence of events in the universe- independent of observation? It seems like so much emphasis is... Feb23-14 03:08 AM adrian_m 6 677 In the spirit of this forum I should first announce: -generally, I have no idea what I'm talking about but look for... Feb23-14 12:29 AM ghwellsjr 6 489 In Special Relativity the example is given of a pole that alternates color, as seen in its own rest frame. Someone in... Feb22-14 09:56 PM gabeeisenstei 19 699 Before I get down to business, I would like to note (you don't have to read this; feel free to skip to where it says... Feb22-14 06:31 PM pervect 2 316