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Feb2313 08:40 AM
ZapperZ

1 
40,732 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
40,379 
If T_{ab} = \rho u_a u_b is the stress tensor for dust. How can I show that T^{ab}_{;b} = 0 mean that dustparticles...

Feb1708 05:28 PM
TheMan112

0 
989 
I am reading Taylor and Wheeler's Spacetime Physics. I am enjoying it a lot and find it extremely readable but I have...

Feb1708 05:01 PM
Ed Quanta

0 
1,254 
Hey folks,
Does anyone know how to get the line element on a torus? The ds^2 term.
I want to find the metric...

Feb1708 04:38 PM
robousy

2 
2,584 
Hello everybody, this is my first post here.
I need help with a task in General Relativity.

Given we...

Feb1708 10:19 AM
CompuChip

10 
3,032 
The idea is that you have a clock at the origin of some frame O. In order to synchronize this clock with 2 other...

Feb1708 06:28 AM
Doc Al

7 
2,238 
Good day to you all, I am total amateur so people with high physics degree dont need to waste their time since this...

Feb1608 04:02 PM
Tachyonie

2 
1,400 
I was thinking about how one would teach special relativity using a spacetimegeometric approach. I think you would...

Feb1608 09:12 AM
Fredrik

16 
4,294 
Well, it's an interesting thought, but one that I can't quite believe, or maybe more I can't understand how, something...

Feb1508 08:44 PM
RetardedBastard

65 
7,566 
Rereading "On the Electrodynamics of Moving Bodies" by A. Einstein from 1905 (English translation I found on the...

Feb1508 06:23 PM
W.RonG

6 
1,751 
As we know, Bondi derives the Lorentz transformations (LT) via the radar detection of the spacetime coordinates of a...

Feb1508 03:31 PM
bernhard.rothenstein

7 
1,973 
i've never been good at putting my thoughts into words...so i was hoping someone could pickup on my theory, maybe even...

Feb1508 11:43 AM
HallsofIvy

1 
1,455 
When searching for KK stuff in forums, I see that when g(5) is applied to L(5 R), this effectively splits the equation...

Feb1508 10:51 AM
MikeL#

13 
3,532 
Hi im new to understanding the theory of relativity so please excuse me. I can make sense of most of it. The one thing...

Feb1408 07:55 PM
CaptainQuasar

8 
1,640 
Imagine a solid chain from the Earth to the moon's surface (which I believe is 1.5 light seconds away).
Now Imagine...

Feb1408 04:00 PM
russ_watters

4 
1,314 
Does anyone know of any good tutorials for grtensor (for maple) other than the documentation that comes with the...

Feb1408 12:14 PM
Pacopag

0 
4,239 
How do you argue that the equation for time dilation derived from studying a light clock can be used in general. For...

Feb1408 11:32 AM
country boy

3 
2,639 
Could someone pleases either:
a. Justify the notion that the Lorentz interval between two events is independent of...

Feb1408 06:58 AM
DrGreg

15 
3,512 
Hello all.
I asked this question as a subquestion in another thread where it was perhaps inappropriate. It is very...

Feb1308 11:12 PM
JesseM

9 
1,673 
This thread is another extending from the `Schwarzschild Metric` and `Climbing out of a Black Hole`. I hope the...

Feb1308 10:34 PM
yogi

6 
2,011 
I ahve always wondered why only the curvature term R_{\mu,\nu} been considered in GR. From differential Geoetry, how...

Feb1308 04:47 PM
geoffc

2 
2,112 
The time dilation equation:
\Delta t' = \Delta t/\sqrt{1  v^2/c^2}
Now lets consider a tachyon with v = 2c
...

Feb1308 04:20 PM
DaleSpam

71 
27,406 
Hi everyone;
I'm new to both PF and GR, so please bear with me if I'm not being very clear, or using standard syntax...

Feb1308 10:05 AM
haushofer

3 
2,526 
Forgive me if this has been posted before, but looking through a page of search entries I found many topics that were...

Feb1208 04:44 PM
yuiop

19 
2,771 
If we impose that under no force or gravitational field Lorentz transform must hold, my question is if the validity of...

Feb1208 01:04 PM
yuiop

2 
1,807 
Let’s put an observer in a 3D frame of reference at x=0, y=0, z=0 to observe one of Einstein’s thoughtexperiments. ...

Feb1208 06:24 AM
JesseM

3 
1,483 
Hi,
I am new to this forum so I apologise if a similar thread already exists.
I am trying to resolve the...

Feb1208 06:19 AM
Ich

10 
4,169 
Proof that pressure is invariant on the front and back faces of the moving box.
(We are already agreed in another...

Feb1108 11:40 PM
yuiop

44 
5,794 
why no one use the Special or General Relativity in QM (Quantum mechanics) ...
when QM studies particles that move...

Feb1108 11:31 AM
Tom Mattson

8 
1,900 
If it has been determined that time/space is always relative to gravity as observed in several equations (correct me...

Feb1108 10:03 AM
masudr

11 
3,612 
Suppose 2 particles are heading towards each other at a speed very close to the speed of light (relative to a...

Feb1108 05:15 AM
itsjustme

4 
1,525 
Now, It is has been derived from GR that the pressure within a substance contributes to it's gravity just as it's mass...

Feb1008 07:17 PM
pervect

16 
3,535 
why haven't there been any observations of planets or stars or anything near a black hole's event horizon being...

Feb1008 03:25 PM
mathman

3 
1,426 
By way of explanation, I am on a learning curve as far as relativity is concerned, but then this might be true for...

Feb1008 11:12 AM
pervect

4 
1,606 
How do you get gravitational waves or gravitons out of the EFE? It certainly doesn't look like a wave equation. Are...

Feb908 02:16 PM
joelperr

2 
1,123 
Nothing can be said about an objects speed in space unless it is compared to the motion of another object.
1. Can...

Feb808 10:30 PM
JesseM

15 
3,285 
It occurred to me that, as far as calculating the position or movement of objects a reference frame can be rotational,...

Feb808 03:45 PM
CaptainQuasar

3 
1,675 
S = a stationary onedimensional coordinate system. The x'axis of another onedimensional coordinate system S'...

Feb808 12:17 PM
arbol

6 
1,866 
Why did Einstein chose R_ab  1/2 g_ab R = k T_ab the Right side is basically saying the mass/energy causes the...

Feb708 09:03 PM
Phymath

2 
1,834 
Since everything in the universe is moving relative to the other, how can one measure an absolute velocity? Therefore,...

Feb708 08:07 PM
pervect

14 
2,054 
Can anyone explain to me how to expand this expression for curl which I find in the GR book I'm reading (by Hobson,...

Feb708 04:40 PM
Mentz114

12 
2,497 