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

Dec3107 02:06 AM
jtbell

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41,363 
Before posting anything, please review the Physics Forums Global Guidelines.
If you are seeking help with a...

Feb2313 08:40 AM
ZapperZ

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41,729 
Okay because my previous post of similar kind was I guess rather too full of thought experiments and ideas that nobody...

Aug2113 04:08 PM
Simon Bridge

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678 
Consider some material object, more or less rigid, with two ends, A and B, like
AB
It is at rest at a point...

Dec2707 06:07 PM
pervect

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1,979 
I know that there is an equation for an accelerating object that is already a notable fraction of the speed of light...

Nov213 12:01 AM
pixelpuffin

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903 
Difficult to explain this question but i will try, Space is expanding
and un gravitationally bound matter is carried...

Feb1805 10:55 AM
chronon

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3,738 
Maybe this should be in the classical physics section, but there is a connection with GR so I'm posting here.
I've...

Sep208 08:24 PM
Mentz114

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2,078 
I am thinking about train paradox here. The only difference between the passenger and the person waiting at the...

May2111 11:38 PM
ZealScience

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1,013 
Consider two point charges in space: one positive(+Q) and other negative(Q), lying on the yaxis and separated by...

Jul411 10:02 AM
lovetruth

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5,949 
Does anyone have any references in the literature that talk about interpreting forces as Christoffel symbols?
...

Dec1111 10:54 PM
atyy

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1,787 
To avoid hijacking an existing thread, I wanted to start a new one on how "gravitational forces" are represented in...

Jul2912 07:39 AM
Mentz114

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2,359 
Let's tie a rope on an object, then we swing the object around in a circle, then we start running forwards while...

Oct2713 07:07 AM
DaleSpam

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12,124 
I was wondering why can't I use formulas from the "Special Relativity" in cases like:
F=mv^2/r Or F=qv•B...

Jul2214 12:56 AM
ghost313

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611 
I am attemting to help my son with a Physics problem, and it has been 20 years since my last Physics class. I would be...

Feb904 06:49 PM
Bigniko

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1,298 
In my general relativity class my professor derived the form of the KruskalSzekeres form of the Schwarzschild metric...

Oct1912 02:25 PM
Airsteve0

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1,027 
This is a fairly trivial question I think. I'm only asking it here because after some googling I was unable to find...

Aug1412 07:26 PM
LittleSailor

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886 
Considering how the various forms of equivalence principle can lead to ambiguous discussions, I would like to know if...

Jan1507 10:24 AM
Crosson

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1,762 
i am read a paper of name: "formalism for an extended object"(in spanish)..
a sub manifold of coordinates y^i...

Nov1809 05:11 PM
alejandrito29

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787 
Does anyone have any information on this experiment involving Einstein's prediction of the speed of gravity? Was it...

Feb607 07:40 AM
Satie

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3,929 
Hello;
I know that the formula for density is mass/volume. However, this is only true for rest mass. What about...

Mar1710 02:44 AM
FeDeX_LaTeX

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1,341 
If a stationary observer throws a rock out in the radial direction in a Schwarzschild geometry, what is the...

Nov2808 02:21 AM
Ich

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1,202 
i have looked on the net for a formula that would give me an idea
of how much gravitational energy verses other...

Nov403 03:45 PM
wolram

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2,491 
I was just wondering if there is a simple formula for determining how much a horizontal light beam deflects in an...

Aug512 03:30 PM
wmikewells

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1,214 
what is the formula for the acceleration felt by an accelerating object? I've spent days googling and cant get a...

Sep2408 05:03 AM
granpa

6 
1,520 
As you know,the formula for doppler effect is:
f^{'}=\frac{vv_{o}}{vv_{s}}f
relativity suggests(at least I...

Nov1011 10:28 PM
ghwellsjr

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2,431 
I am trying to understand where the EinsteinHilbert action comes from.
Neglecting a constant multiplier, Wikipedia...

Dec409 10:28 AM
AEM

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2,802 
this is a question more about the history of the field equations, but did Einstein get his field equations originally...

Jun1608 06:02 AM
haushofer

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1,152 
In the 19th century they believed in the absolute motion and the ether, and they were searching for a scientific proof...

Oct313 04:56 PM
DaleSpam

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5,393 
Chapter 9 on the theory of relativity discusses a thought experiment (http://www.bartleby.com/173/9.html) about a...

May412 12:37 AM
mananvpanchal

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3,343 
Hey, i don't know if this is the right spot to post this question, but I was reading "The Universe in a Nutshell" by...

Oct1604 07:55 PM
Demiwing

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1,297 
I'm looking for a good text on the foundations of GR. Geared towards physicists, but with a focus on the subtleties of...

Jul3112 02:33 PM
Naty1

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574 
Hi everyone,
I've been reading posts here occasionally, and have been impressed with the amount and quality of...

Oct3013 09:56 AM
PeterDonis

22 
1,878 
I'm having trouble interpreting the four dimensional version of Gauss' law. In the original version, a vector would be...

Jul912 11:28 AM
ApplePion

7 
1,784 
About momentumenergy vector ,we have :
\vec{P}=(\vec{p},i\frac{E}{c})
and four dimentianal wave vector :
...

Aug212 02:32 AM
zhangyang

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476 
I attempted to derive a fully expanded expression for the force four vector
The four velocity being > (γ,γv)...

Jul2012 03:04 PM
DrGreg

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619 
Suppose that some relativistic field has energy density and momentum density. Integrating these, we get the total...

Oct2707 05:48 PM
samalkhaiat

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5,956 
Hi, I'm trying to reconcile some general relativity stuff and I'm getting confused on a few topics.
Would someone be...

Dec811 12:58 AM
PAllen

13 
2,560 
Hi,
I have just been pondering the problem of electron  positron annihilation into a single photon in the CM...

Oct1908 12:56 PM
clem

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3,305 
I've been trying to see how relativity shows that the quantity gamma*m*c^2 (total energy) is conserved. I assumed that...

Oct3004 05:46 AM
Garth

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3,660 
What is the simplest way to find out if a physical quantity is the component of a four vector? There are opinions that...

Feb1109 02:44 AM
bernhard.rothenstein

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1,655 
Hey I'm reading about relativity and I stumble across statements such as if a fourvector is timelike then it's always...

Jun112 12:59 PM
George Jones

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1,805 
Does anyone know where I can find a mathematical proof that the norm of any fourvector is Lorentz invaraint?

May904 04:50 PM
DW

1 
1,546 