# 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: 2,466 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 42,469 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 42,118 I feel I understand relativistic velocity addition fairly well. However, the way I usually see it modeled is with two... Aug14-14 05:14 PM DiracPool 6 476 My understanding is that a light beam will bend in an upward accelerating elevator. I told my uncle this. He responded... Aug14-14 03:42 PM rlshuler 7 631 This expression: \Gammaavc\Gammacab Can someone please show me how to multiply the two Christoffel symbol... Aug14-14 12:45 PM HallsofIvy 1 184 In my studies of methods to simplify the Einstein field equations, I first decided to go about expanding the Ricci... Aug14-14 06:33 AM space-time 1 295 Or stated otherwise: Is it possible, due to other effects than mass for a non-spinning object with inertial mass n to... Aug14-14 04:05 AM timmdeeg 22 991 Hello, I thought of something after watching this video on the theory of relativity.... Aug14-14 03:12 AM ghwellsjr 10 282 Error below :grumpy: For a couple of years now, I have been attempting to solve for the values in GR of the time... Aug13-14 06:22 PM robphy 11 463 Hey guys, this is a question that has been bothering me since I finished my special relativity course last year. I... Aug13-14 08:00 AM jtbell 12 640 If you can "catch up" to the light reflected from the Earth at that time in the past. What kind of resolution would... Aug13-14 03:13 AM Gerinski 4 407 When you have a general coordinate chart on spacetime you have a lot of freedom to pick your coordinates, but you are... Aug12-14 07:03 PM Fredrik 1 217 The Riemann curvature of a unit sphere is sine-squared theta, where theta is the usual azimuthal angle in spherical ... Aug12-14 04:16 PM pervect 13 357 When neglecting gravity and body size, if a body rotating at uniform angular velocity about a central body sends a... Aug12-14 01:49 AM HALON 3 293 if we know K^{a b}= (∇^a*ζ^b -∇^b*ζ^a)/2, ζ is a killing vector, under the variation of metric g_{a b}→g_{a... Aug11-14 05:34 PM WannabeNewton 6 473 In Carroll's we read ...The Unruh effect teaches us the most important lesson of Quantum Field Theory (QFT) in... Aug11-14 03:38 PM Matterwave 1 288 I was looking up ways to solve the Einstein field equations when I came across a couple of sources. ... Aug11-14 08:20 AM robphy 2 308 I am pretty sure this question must have been asked before... However I was always wondering, what would a theory be... Aug10-14 06:45 PM ChrisVer 3 383 Two spaceships approach an observer from an equal distance and from an opposite direction with an equal speed in the... Aug10-14 08:08 AM Nugatory 2 381 This is a conceptual problem, right out of a book. Say Mavis is moving in a spaceship at 0.6c relative to Stanley on... Aug10-14 02:47 AM ghwellsjr 11 427 Theoretical question.... If an extremely long object approached the event horizon, let’s say a torpedo shaped craft 1... Aug9-14 07:11 PM pervect 6 366 Why photons can't go any slower than the speed of light, in vacuum? Or if they could, then why they don't? Aug9-14 03:41 PM DaleSpam 74 1,727 Dear all, I was reading this... Aug9-14 03:04 PM dextercioby 2 208 If you have two counter-rotating streams of particles traveling at near luminal velocity then is there effective... Aug9-14 10:25 AM jtbell 4 376 I have a little bit confuse on the Simultaneity I know if there are 2 coordinates. One coordinate S' is moving V... Aug9-14 09:57 AM ghwellsjr 6 452 Recent data in qm suggest black holes could decompress into a white hole on either our universe or another as such is... Aug8-14 11:42 PM PeterDonis 1 313 I'm sure that most people on these forums are familiar with the similarities between compressible flow in aerodynamics... Aug8-14 12:27 PM jlefevre76 6 579 I have question on my own understanding.. So please correct me.. 1. It is said that mass of photon is zero; Or it... Aug8-14 10:29 AM jlefevre76 24 1,139 The free field Einstein-Maxwell action is often states as S = - \frac{1}{4}\int_M F^{\mu \nu} F_{\mu \nu}d^4 x +... Aug7-14 11:24 PM Matterwave 1 299 Ok, so if I were to travel towards a black hole at close to c, would the event horizon become visible? Let us... Aug7-14 01:31 PM tionis 41 1,448 hi, i am stucked with a confusion about michelson-morley experiment. I am not going into mathemtaical detail, the... Aug7-14 01:37 AM ghwellsjr 15 461 Meter sticks laid out around the rim of a rotating disk will foreshorten by the Lorentz factor. This means more of... Aug6-14 10:10 AM WannabeNewton 8 407 Consider two equal and opposite charges moving in the same direction and velocity v0, and are separated a distance R. ... Aug6-14 04:07 AM KatamariDamacy 13 464 Basically I am trying to lorentz transform the magnetic field along θ of a bunch particles which have a gaussian... Aug6-14 03:12 AM matt_crouch 4 293 Hi all, I am really curious about the final state conjecture in general relativity, but I don't really understand... Aug5-14 03:36 PM bcrowell 2 276 http://i57.tinypic.com/2j5n9s4.jpg We’ve all seen this little fellas up there. Two brothers, twins, in their 60’s.... Aug5-14 07:34 AM DaleSpam 3 317 when muons are created in the atmosphere and fall to earth the earth clock runs faster. Thus, the "slower" muon clock... Aug4-14 10:08 PM PAllen 2 218 Do experiments like 1971's Hafele & Keating show that SR relativistic effects of time dilation are not mere products... Aug4-14 03:50 AM pervect 16 878 Hi all, I was thinking about special relativity and spacetime and had the thought of measuring our velocity with... Aug3-14 08:59 PM Matterwave 8 451 I understood that the basic idea of the Michelson-Morley experiment was to measure the velocity of light, as seen from... Aug3-14 11:18 AM ghwellsjr 4 431 Ok so I read this on another site... "the Milky Way is part of the Local Group...The Local Group is calculated to move... Aug3-14 02:42 AM sublime56 9 483 Hi Just wondering about the orbital path of a high speed particle - eg electron in orbit. Is it length contracted?... Aug2-14 11:24 PM jartsa 3 350