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Feb2313 08:40 AM
ZapperZ

1 
42,385 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,028 
This is a followup to another thread I started, on the current status of Newton's theory of gravity as compared with...

Aug3011 11:46 AM
clisp

3 
1,212 
A gigantic machine that has let's say another 1000 machines inside of it. We start the primary machine to travel at...

Aug3011 10:21 AM
ghwellsjr

14 
1,838 
Can someone provide for a layman a positive definition of space? I am looking for a definition of what space is,...

Aug2911 11:38 AM
DaleSpam

16 
2,451 
Hello, in a paper http://wwwlibrary.desy.de/preparch/conf/theows/workshop2004/data/Chatillon.pdf .
says that.
...

Aug2911 10:59 AM
WannabeNewton

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2,789 
in einstein train thought experiment, if two bulbs were placed, in the front and rear of a moving train. And a person...

Aug2911 05:02 AM
Doc Al

13 
2,805 
Hello
I don't undestand what means that the gauss bonnet lagrangian in 4D
L = ...

Aug2911 12:52 AM
alejandrito29

0 
885 
I only know time dilation in it's basic form and it was explained to me beautifully using mirrors in a spacecraft. The...

Aug2811 03:55 PM
Janus

2 
1,227 
What are the causes that led einstein formulate curvature of spacetime?
what it has to do, if any, with the...

Aug2811 01:27 PM
Bill_K

1 
1,055 
Is anyone here familiar with the Vaidya/LemaitreTolman metrics? Wiki claims that they're both used to model radiating...

Aug2811 12:16 PM
George Jones

9 
2,182 
I know that Newton's theory of gravity fails to predict certain features of Mercury's orbit in comparison with GR, and...

Aug2811 08:37 AM
chaszz

4 
1,581 
I try to determine the speed of muons. In an book I have there's an exercise regarding muons.
Given that they half...

Aug2811 08:32 AM
yuiop

7 
1,771 
I have never been formally trained in GR, and have a question regarding the basics of how to calculate the energy...

Aug2811 01:51 AM
K^2

7 
1,249 
Suppose an experimenter firstly is entirely ignorant of general relativity and noneuclidean space. He finds (say) a...

Aug2711 02:46 PM
utesfan100

9 
2,177 
I'm going to attempt to start a beginner GR book since we're covering it in Modern Physics and I've been covering the...

Aug2711 01:58 PM
Elwin.Martin

2 
1,271 
Can someone explain why the covariant derivative of g_{\alpha\beta} with respect to x^{\lambda} is always zero?
I am...

Aug2711 01:29 PM
JDoolin

30 
2,992 
Lets say we have a frame of reference moving at, say, 10% speed of light.
In it is a nuclear reactor (fusion or...

Aug2711 07:29 AM
jtbell

4 
2,071 
Hi
If two events are separated by a timelike interval, then all inertial reference frames will agree on the order of...

Aug2711 12:58 AM
PeterDonis

1 
2,633 
Interferometrics Cart
http://negrjp.fotoblog.uol.com.br/images/photo20100912153045.jpg
Imagine that a cart is...

Aug2611 10:36 PM
D H

10 
2,282 
If you were infinitely close to the speed of light, and you attempted to take a picture of yourself, would it work?...

Aug2611 03:02 PM
DaveC426913

44 
4,373 
Hi. I can't find a source that shows how to superpose two metrics.
For example, superposing Schwarzchild metric
...

Aug2611 01:01 PM
inottoe

6 
1,242 
My text explains that free float frames are locally indistinguishable from flat spacetime in the sense that in a...

Aug2511 11:53 AM
Bill_K

2 
1,046 
What happens to the Schwarzschild metric for an isolated nonrotating body when the horizon radius is inside the body?...

Aug2511 08:54 AM
George Jones

7 
1,948 
ok, this is realy bugging me that i cant figure it out and it just agitates me all day long. I've heard explanations...

Aug2511 04:59 AM
K^2

19 
5,151 
We've known for a while that the Pioneer anomaly couldn't be gravitational:
Iorio, "Does the Neptunian system of...

Aug2411 11:40 PM
atyy

39 
5,853 
Hi,
I ran this by my friend awhile ago and I'm not sure how to feel about it still... Consider the following:
...

Aug2411 09:07 PM
robphy

16 
1,861 
2 space stations are separated by a distance of 10 light years and are at rest wrt each other. I set off from A to B...

Aug2411 06:36 PM
rede96

2 
1,526 
I am aware that the following operation:
mathbf{M}_{ij} \delta_{ij}
produces
mathbf{M}_{ii} or...

Aug2411 07:14 AM
dextercioby

7 
2,533 
Hi, everyone
I'm now reading A Relativist's Toolkit by Eric Poisson.
In chapter 3, he say something about...

Aug2311 05:20 PM
WannabeNewton

9 
1,660 
I've worked through a commonsense argument1 , 2 showing the timetime component of the Schwarzschild metric
g_{tt}...

Aug2311 01:51 PM
pervect

7 
1,845 
Let r_{\mu} be a tensor in coordinates x^{c} and R_{b} be a tensor in coordinates X^{c}.
Then let r_{\mu} = 0.
...

Aug2311 07:26 AM
grzz

7 
1,181 
\partial_u \partial^u
Isn't this like a box symbol? How is it written out again? You can write it out in 2...

Aug2211 04:31 PM
LostConjugate

5 
1,228 
I have been reading around in general relativity, and see that, for Quantum Field Theory in Curved Spacetime, the...

Aug2211 12:05 PM
Bill_K

1 
1,135 
I may have the option my senior year to take a GR class at the graduate level. I was wondering if taking this class...

Aug2211 07:43 AM
K^2

6 
1,341 
i constantly feel that newton was right in measuring the relative velocity.einstein makes use of light which has a...

Aug2211 02:32 AM
harrylin

2 
1,030 
Some friends and I were out at a pub last night and this question came up.
If you were in space and you had two...

Aug2211 02:06 AM
harrylin

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3,026 
From my internet research I gather that they are very hard to detect but is that because the energy carried by the...

Aug2111 05:28 PM
mrspeedybob

11 
1,804 
Hi everyone. So basically I am still struggling to find a description of the derivation of relativistic momentum (via...

Aug2111 04:38 PM
jimbobian

6 
1,551 
please let me know what is a significance of lorentz factor,and what will happen if lorentz factor is not multiplied...

Aug2111 09:00 AM
bodhi

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2,192 
Gou et al., "The Extreme Spin of the Black Hole in Cygnus X1," http://arxiv.org/abs/1106.3690
Pretty cool. I'd...

Aug2111 05:34 AM
martinbn

8 
2,547 
Before I post this, I want to assure everyone that I am not a conspiracy theorist who doubts Einstein or relativity...

Aug2011 01:21 PM
ghwellsjr

9 
2,238 