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Feb2313 08:40 AM
ZapperZ

1 
42,297 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
41,926 
I would appreciate it if some senior member would give me feedback about this result that I have been using in my...

T 09:30 AM
m4r35n357

3 
253 
We know how the curvature of a vector V or a manifold is depicted by the following formula:
dx\mudx\nu\nu , ∇\mu]V...

T 07:08 AM
stevendaryl

2 
180 
I would like to think that I understand how 4velocity is defined in special relativity. It makes sense to me that one...

T 04:42 AM
stevendaryl

4 
147 
Hi,
On p.4 of "A First Course in General Relativity", Shutz says that we redefine the units of time so that the new...

T 01:55 AM
porcupine137

18 
325 
The at rest distance between Betty the astronaut and a flag in open space is 1 unit. If Betty approaches the flag at...

T 12:56 AM
HALON

24 
735 
Hi guys, i've been thinking about this experiment for the last few hours and I have a few questions which I am deeply...

T 12:31 AM
Orodruin

9 
331 
What if Schwatzchild has made the same mistake as Newton?
( 1  2MG / c2 r ) dt
can be view as a binomial...

Y 11:24 AM
PeterDonis

5 
227 
Hi
I am in a debate with some creationists. They are claiming that the speed of light changes in strong...

Y 10:56 AM
PeterDonis

7 
191 
Hi,
I'm interested in trying to understand Einstein's field equations, I'm a physics student due to start an...

Y 10:31 AM
stevendaryl

3 
175 
In this source explaining how to derive the Schwarzchild metric, the person came up with an ansatz and worked from...

Y 08:31 AM
Nugatory

1 
106 

 
 
 
Does the following argument prove that any method of faster than light communication is impossible?
1. A...

Y 01:53 AM
Mark_Laverty

74 
2,118 
Depending on where I go to get a good understanding of the Lorentz transformations, I run into two formulas for time...

Y 12:22 AM
Nugatory

2 
179 
It is known that, by the expansion of the universe, galaxies that are roughly 4200 megaparsecs away travel away from...

Aug2014 05:12 PM
phinds

15 
735 
Question the thing in the region of space that cannot be seen from us because they recede faster than the speed of...

Aug1914 08:08 AM
phinds

2 
220 
I know that the example of time dilation and length contraction due to Special Relativity is usually given as the...

Aug1914 05:06 AM
Nugatory

2 
232 
I'm looking for proof that Wolfgang Rindler coined the term Event Horizon. I believe that it was Rindler because...

Aug1914 03:34 AM
PhysicistMike

3 
229 
First, here is my source: http://www.thescienceforum.com/physics/30059solvingeinsteinfieldequations.html
As...

Aug1814 10:40 PM
PeterDonis

5 
351 
As you may already know, given a timelike congruence describing some extended body with worldtube ##\mu## embedded...

Aug1814 06:41 PM
WannabeNewton

47 
4,493 
From what I know, to get the reverse trace form of the Einstein field equations, you must multiply both sides by gab...

Aug1814 03:14 PM
pervect

3 
238 
Hello, i am new here.
I have been studying SR en GR for a while on a hobby level,
and i keep pondering on the...

Aug1814 12:50 PM
phinds

37 
823 
If time is being warped by gravity/accelerated motion, does that mean that our clocks are inevitably slowed down since...

Aug1814 12:04 PM
PeterDonis

7 
318 
Is space time like a bowling ball on a trampoline or does it surround all matter like water does a submerged object?

Aug1814 06:44 AM
tom.stoer

15 
475 
Has this idea been recognized outside Frankfurt?
http://arxiv.org/abs/0812.1738
Pseudocomplex General Relativity...

Aug1814 05:28 AM
MrR

1 
282 
After learning more about relativity, and the vast amount of knowledge that is on this forum, I would like to clear up...

Aug1714 08:28 PM
jbriggs444

2 
199 
Here is my basic question:
Lets say we have a massless charged shell with charge q and radius R. Is there some R...

Aug1714 08:26 PM
PeterDonis

34 
4,607 
A first stage of the determination.
We have a body of length L = AB, which moves along the xaxis with velocity v,...

Aug1714 07:37 PM
atto

31 
1,027 
Imagine a theoretical universe which contained only two photons with the same energy. Imagine that each photon began...

Aug1714 05:55 PM
Sting33

18 
738 
In the Wiki article about the Vaidya metric :
http://en.wikipedia.org/wiki/Vaidya_metric
there is mention of a...

Aug1714 07:21 AM
George Jones

3 
215 
How is gravity created? If you have any theories or new facts discovered please share. If u have your own theory...

Aug1714 05:08 AM
Chronos

18 
699 
In General Relativity spacetime is described by a metric. The most common one is the Schwarzschild metric, valid at...

Aug1614 04:39 PM
rlshuler

3 
246 
I think this will be a quick question...
If the Schw's metric is a solution of the vacuum, then what does the mass...

Aug1614 02:35 PM
Nugatory

3 
308 
I was watching a Science Video explaining why Ligtht travels slower in a Transparent Medium than in a Vacuum.
I...

Aug1614 12:37 PM
ChrisVer

5 
329 
Here is a new video, addressing a common question on this forum:
jlTVIMOix3I
It's similar to that one, but has...

Aug1614 08:35 AM
Greg Bernhardt

1 
444 
They say there is no measurement if travelling in a ship at the speed of light you can do to tell whether you are...

Aug1514 09:48 PM
PeterDonis

76 
1,457 
Recently read about a release from 2006 about an electromagnetic superconductor that generated a small gravity field...

Aug1514 06:42 PM
Fival

2 
240 
I've found the equations of motion for a charged test particle in the KerrNewman geometry from a number of sources. ...

Aug1514 01:44 PM
michael879

0 
259 
How can we define SPACE TIME CURVATURE with respect to dark energy and dark matter ?

Aug1514 01:35 PM
timmdeeg

2 
301 
Hi everyone,
I have a few questions about relativity.
I've been reading about relativity and its effects and I...

Aug1514 01:23 PM
Barry911

11 
525 
i have a question, that nobody seems to be able to answer : is math actually suited for reality ? Basically the idea...

Aug1414 09:05 PM
phinds

5 
805 