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Feb2313 08:40 AM
ZapperZ

1 
41,654 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
41,299 
What are the equations that shows that time slows down as you near a black hole? I'm trying to prove to a...

Jul514 04:50 PM
PeterDonis

7 
1,452 
Dear All,
I am teaching myself tensors for the first time. I am using D'Inverno's book and got stuck at page 73....

Jul514 04:19 PM
Matterwave

5 
1,333 
The symbol, c, represents both the speed of light and the speed of sound in most scientific reference texts. Can the...

Jul514 11:46 AM
DaleSpam

54 
9,530 
By theoretical calculations of super dense black holes show their gravity exceeding to a limit that can pull in light...

Jul514 10:14 AM
stevebd1

11 
2,060 
Hey all,
I've been reading "Time Travel and Warp Drives" by Allen Everett and Thomas Roman, and the book had an...

Jul514 09:03 AM
DaleSpam

3 
1,096 
I am curious to know the various opinions, what ideas you favor as to the cause of inertia? What could the reference...

Jul414 04:58 PM
yogi

25 
4,986 
I've heard that a changing magnetic field creates an electric field and vice versa. So if shoot an electron in a...

Jul414 04:16 PM
Nugatory

3 
986 
Hello guys, I just had to ask a quick question about the nature of light. In different synchronization parameters...

Jul414 03:33 PM
DaleSpam

9 
1,784 
Hey guys,
as this is a basic QFT question, I wasn't sure to put it in the relativity or quantum section. Since this...

Jul314 09:31 PM
jk86

1 
1,099 
If someone stands up through the sunroof of a car travelling down the freeway at 60 mph and measures the speed of a...

Jul214 05:58 PM
nikkkom

10 
1,509 
Hi all,
What is the difference between Lorentz transformations and yt?. That is, the Lorentz transformations for...

Jul214 04:12 PM
pervect

6 
1,185 
SR is a theory based on flat spacetime, and all of its effects are there in a flat spacetime framework.My question...

Jul214 03:28 PM
WannabeNewton

30 
3,965 
After my studies of metric tensors and Cristoffel symbols, I decided to move on to the Riemann tensor and the Ricci...

Jul214 01:45 PM
ChrisVer

15 
1,560 
Hello guys!
I've been trying to get some intuition for differential forms. I know the formal theory and I know how...

Jul214 09:26 AM
micromass

2 
981 
This bothers me, and the question is simple:
If am working with a nonminkowski metric g, when raising or lowering...

Jul214 09:22 AM
WannabeNewton

3 
1,090 
Hi all,
Is it possible to derive the equation p = ymv, and hence based on this, kinetic energy formula, without...

Jul214 09:01 AM
pervect

5 
1,115 
I have read some basics knowledge about General Relativity and I see that it deal perfectly with gravity. But what...

Jul114 08:27 AM
WannabeNewton

6 
1,209 
A second SR question that has been on my mind lately is that of hyperbolic nature of Minkowski space. The fact that...

Jul114 06:24 AM
pervect

4 
1,031 
Hey guys,
in classical mechanics Newton's law of universal gravitationa force says that the force between two...

Jul114 02:22 AM
haushofer

10 
1,422 
I just derived the 3D Cristoffel symbol of the 2nd kind for spherical coordinates. I don't think I made any careless...

Jun3014 11:10 PM
PeterDonis

6 
926 
According to my understanding of SR, a light photon traveling at c, of course, relative to me "experiences" no time. ...

Jun3014 09:23 PM
PeterDonis

7 
1,043 
Sorry if I mess up some terms, im not a physics guru in any way.
To my understanding, the universe inflates like a...

Jun3014 07:15 PM
PAllen

9 
1,386 
I was just thinking about this, and from a perspective of an inertial frame, it's easy to see how distances contract,...

Jun2914 08:39 PM
DaleSpam

5 
1,440 
I recently derived a matrix which I believe to be the metric tensor in spherical polar coordinates in 3D. Here were...

Jun2814 11:39 AM
spacetime

2 
849 
Static spacetimes can be defined as having no g_{tx} component of the metric.
Alternatively we can say that they...

Jun2814 09:44 AM
WannabeNewton

5 
738 
Bear with me, I am (not even) a chemist.
This is something that bothers me for some time.
The larger the black...

Jun2814 12:33 AM
PAllen

22 
2,992 
Suppose there were a supermassive, superdense hollow sphere. Inside of the sphere, would time move more slowly...

Jun2714 10:45 PM
PeterDonis

7 
990 
There are several threads on the Bell paradox, plus the article in the FAQ forum, but I must be missing something...

Jun2714 07:58 PM
PeterDonis

25 
2,628 
When we talk about spacetime curvature or the curvature of space, how many different "types" of curvature are there...

Jun2714 04:06 AM
Drakkith

10 
798 
Objects with mass always travel less than c with respect to other objects with mass. Objects without mass always...

Jun2714 01:15 AM
PAllen

17 
1,387 
Hello. I was going through the problems in the angular momentum chapter of the text "Problem Book in Relativity and...

Jun2614 09:39 PM
WannabeNewton

22 
1,876 
Hi!
New here. Be gentle.
Kinda an idea that popped into my head a little while ago:
Are the tidal forces of...

Jun2614 08:36 PM
PeterDonis

58 
4,659 
I am trying to get an understanding of general relativity one tidbit at a time. I have a vague concept of why curved...

Jun2614 04:19 PM
pervect

7 
732 
I think I have come across something that invalidates something one of my Physics professors said back in college,...

Jun2514 09:23 PM
DaleSpam

27 
2,009 
I am planning to start self studying GR and, before choosing a better book to use, I have been flipping through an old...

Jun2514 11:31 AM
WannabeNewton

5 
679 
We have the (I think FRW) metric in the coordinates
y^{0}=t,~~y^{1}=\psi,~~y^{2}=\theta,~~y^{3}=\varphi
...

Jun2414 04:32 AM
ChrisVer

5 
862 
I only understand mass and energy according to Newtonian mechanics,
Where mass is the resistance of a body to...

Jun2314 02:06 PM
pervect

3 
674 
It is wellknown that Newtonian's law of gravitation
\Phi(\vec{r}) = \frac{Gm}{\vec{r}  \vec{a}}
for the...

Jun2314 07:45 AM
stevendaryl

20 
1,864 
A lorentz transformed electric field has it's own name. It's called a magnetic field.
That makes me wonder if there...

Jun2214 10:52 PM
pervect

4 
591 
Hello, I have a doubt regarding the postulates of SR.
The two postulates, according to Schutz, are:
1) No...

Jun2114 08:33 PM
Meir Achuz

122 
7,893 