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Feb2313 08:40 AM
ZapperZ

1 
42,799 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,438 
Hiya,
I am a grad student who has had a couple semesters of GR. I am currently perusing a book about Two Spinors in...

Feb1014 02:34 PM
dozappp

0 
317 
I thought that one of the features of GRT was to allow for ACCELERATING reference frames. Yet none of my textbooks...

Feb1014 11:38 AM
DaleSpam

15 
875 
There are only two frame moving relative with each other at certain velocity. One frame see the other going right and...

Feb1014 09:22 AM
Nugatory

1 
343 
The popular thought experiment states, that if of two identical twins one is left on earth an the other is embarked on...

Feb1014 09:14 AM
scienalc

2 
402 
Hi,
I decided to learn about relativity with this book, and I'm looking for people who would like to read it with...

Feb914 05:19 PM
strangerep

3 
640 
page 71 he appears to define the affine connection in terms of derivatives on the locally inertial coordinates with...

Feb914 04:39 PM
thoughtgaze

9 
439 
I had a quick question about Time Dilation and Length Contraction.
Are the two just different ways of...

Feb914 01:41 PM
phyti

14 
571 
From what I understand, Hawking radiation results when one virtual particle (of the pair) falls into the black hole...

Feb914 12:17 PM
PeterDonis

1 
360 
I am trying to derive the geodesic equation by extremising the integral
$$ \ell = \int d\tau $$
Now after applying...

Feb914 11:47 AM
Nabigh R

3 
380 
I have a question regarding world lines and Minkowski diagrams. I have been looking everywhere for an answer and can't...

Feb914 02:27 AM
ghwellsjr

2 
453 
Thanks for the answers on my previous thread, it made some sense, and if I'll reply if there's further misconception....

Feb814 03:12 PM
phyti

42 
1,861 
Hi,
I'm just beginning to learn relativity, but I have a question about why gravity is so different from other...

Feb714 08:08 PM
WannabeNewton

4 
553 
hi everyone. i'm having trouble understanding the concept of proper time in general relativity.
suppose we have...

Feb714 06:04 PM
pervect

31 
1,083 
I have a pretty basic question  one that should have occurred to me long ago, but I never really thought about...

Feb714 03:12 PM
A.T.

11 
558 
I'm not sure if this is the right forum.
I'm sorry, but I'm not good at Physics or English (which is not my first...

Feb714 01:02 PM
waitedavid137

8 
563 
Hello! This is regarding problem 10.4 in Wald. Let ##(M,g_{ab})## be a spacetime, ##\Sigma_{t}## be a one parameter...

Feb714 09:25 AM
WannabeNewton

7 
923 
We know the equations for speed of rotating magnetic field, as N= 120*f/P, where f is frequency of AC currents & P is...

Feb714 07:16 AM
Bill_K

1 
471 
The velocity of an object can, theoretically, only be measured relative to the velocity of another object. If I...

Feb614 01:45 PM
Glurth

9 
437 
In classical mechanics we talk about homogeneous and inhomogeneous gravitational fields.
Do we do this with...

Feb514 09:35 AM
DaleSpam

1 
257 
There is a connection between the origin and the points in the light cone.That is to say,there is a casual...

Feb514 12:17 AM
bcrowell

13 
772 
In flat spacetime, there exists a natural connection that allows you to compare two vectors at different events. Now,...

Feb414 05:33 PM
dextercioby

23 
1,047 
EDIT dw i figured it out, not sure how to remove it though!

Feb414 03:28 PM
tommyj

4 
542 
Lets say I fall into a supermassive black hole's event horizon. Facing outwards towards the event horizon (with the...

Feb414 12:03 AM
Glurth

15 
804 
Hi, I'm doing the master in science and one of things that I have to study is the Gödel metric. His paper have a high...

Feb314 08:56 PM
George Jones

2 
382 
Imagine a 2.3 Ly long box. At the middle of the box there's a half silvered mirror (S) which splits laser beam into...

Feb314 01:55 PM
Vanadium 50

10 
648 
Hello all,
After a brief break from attempting to learn tensor calculus, I'm once again back at it. Today, I...

Feb314 12:46 PM
Nugatory

12 
878 
For a long time I had basically taken for granted the usual interpretation of oneparameter families of orthogonal...

Feb314 12:43 AM
WannabeNewton

4 
685 
I am writing a paper about SR and GR. I have the following:
Special relativity deals with inertial reference...

Feb214 06:03 PM
PAllen

27 
1,716 
As per Maxwell's equations the speed of light is
c = 1/√(permeability X permittivity)
I find that both...

Feb214 04:51 PM
pervect

12 
634 
https://www.youtube.com/watch?v=Cxqjyl74iu4
If the speed at which light waves propagate in vacuum is independent...

Feb214 04:32 AM
ghwellsjr

40 
1,884 
When I look at a minkowski diagram for a black hole I can see that time goes to infinity for the outside observer...

Feb214 02:55 AM
dyb

11 
527 
I have been learning that gravity has a negative energy associated with it. I've heard this stated a couple different...

Feb214 01:19 AM
pervect

13 
789 
Hi
In the Schwarzchild metric, the proper time is given by
c^{2}dτ^{2} = (1 \frac{2\Phi}{c^2})c^2 dt^2  r^2 dθ^2...

Feb114 09:42 PM
waitedavid137

10 
574 
Pretty straightforward, I'm just curious. My current level and understanding of physics has lead me to believe that...

Feb114 05:21 PM
Drakkith

9 
824 
Hi, could anyone help me out?
The FLRW metric in spherical coordinates is:
\;\; ds2 = dt2  a(t)2(dr2 +...

Feb114 04:53 PM
Mordred

36 
1,262 
Hi, I noticed this topic already being discussed but didn't want to hijack the thread with a different question. I...

Feb114 02:36 PM
rede96

14 
714 
Well I am not sure if this thread belongs here or in mathematics/groups but since it also has to do with physics, I...

Feb114 02:32 PM
BruceW

4 
381 
Hi guys... I was wondering if anyone have a sort of a summary of sign conventions in general relativity books. By...

Feb114 12:25 PM
Nabigh R

7 
543 
As it's known, one of the most fundamental aspects of relativity is that all motion is relative.
But when we apply...

Feb114 10:47 AM
ghwellsjr

52 
3,595 
Upon discovering the Starship Titanic while doing some research about time travel, I was wondering what joules would...

Feb114 08:00 AM
waitedavid137

7 
505 