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Feb2313 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...

Dec3107 02:06 AM
jtbell

0 
41,112 
Einstein's article "on the electrodynamics of moving bodies", starts with talking about synchronizing clocks at...

Mar414 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...

Mar414 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...

Mar314 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...

Mar314 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...

Mar314 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...

Mar214 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...

Mar214 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...

Mar214 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...

Mar114 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...

Mar114 01:59 PM
PAllen

3 
513 
I was wondering how is our perception created according to relativity, since what we perceive depends on the...

Mar114 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...

Mar114 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...

Mar114 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....

Feb2814 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...

Feb2814 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...

Feb2814 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...

Feb2814 09:31 AM
jtbell

8 
397 
Bit confused regarding how noninertial frames can be treated in GR (and by noninertial i mean affected by some kind...

Feb2814 01:58 AM
WannabeNewton

1 
288 
I am trying to write the Einstein field equations
$$R_{\mu\nu}\frac{1}{2}g_{\mu\nu} R=\frac{8\pi G}{c^4}T_{\mu\nu}$$...

Feb2714 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...

Feb2714 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 +...

Feb2714 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...

Feb2714 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...

Feb2714 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...

Feb2614 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...

Feb2614 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...

Feb2614 11:29 AM
Yashbhatt

17 
727 
Suppose we have an event horizon H which is a lightlike, closed 2surface. Photons radiated outwards at the horizon...

Feb2514 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...

Feb2514 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...

Feb2514 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...

Feb2514 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...

Feb2514 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...

Feb2414 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.

Feb2414 02:43 AM
mra20x

3 
334 
Could spacetime itself be a field?

Feb2414 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...

Feb2314 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...

Feb2314 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...

Feb2314 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...

Feb2314 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...

Feb2214 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...

Feb2214 06:31 PM
pervect

2 
316 