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Feb2313 08:40 AM
ZapperZ

1 
42,459 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,109 
The Schwarzschild Metric has a form:
##ds^2 = Kdt^2  1/K dr^2  r^2dO^2##
where: K = 1  a/r;
There is a...

T 05:31 AM
wil

48 
886 
http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat
I don't understand, if the radioactive source is put in there...

T 03:25 AM
TheScienceOrca

0 
81 
I have been thinking for the past couple months on how the expansion of the universe effects the matter and energy...

T 02:58 AM
TheScienceOrca

6 
295 
Does this solution mean anything ?
http://www.physicsforums.com/attachment.php?attachmentid=72126&d=1407958868

T 02:40 AM
neilparker62

10 
388 
As you may already know, given a timelike congruence describing some extended body with worldtube ##\mu## embedded...

T 12:57 AM
WannabeNewton

52 
4,974 
I was reading Isaac Asimov's introductory physics text "Understanding Physics". In the chapter on Relativity, he...

Y 09:20 PM
Matterwave

8 
244 
I was recently trying to test something out with the Riemann tensor. I used only 2 dimensions for simplicity sake. As...

Y 07:00 PM
Matterwave

6 
174 
Hello everybody. I was recently brainstorming ways to make the Einstein field equations a little easier to solve (as...

Y 04:36 PM
victorneto

4 
322 
I wondered if anyone had a good online reference on the covariant formulation of Maxwell's macroscopic equations and...

Y 04:30 PM
DaleSpam

10 
274 
Hi,
I'm interested in trying to understand Einstein's field equations, I'm a physics student due to start an...

Y 03:43 PM
victorneto

4 
329 
From what I've understood,
1) the metric is a bilinear form on a space
2) the metric tensor is basically the same...

Y 02:47 PM
victorneto

7 
510 
Due to the blogs being removed, I thought it might be worthwhile posting a few in the forums
zQdIjwoiu4
Time...

Y 02:39 PM
PeterDonis

1 
143 
Due to the blogs being removed, I thought it might be worthwhile posting a few in the forums
From 'Exploring...

Y 06:59 AM
stevebd1

0 
144 
Hi,
How can null geodesics be defined?
Obviously the concept of paralleltransport, of the tangent to the...

Aug3014 11:27 AM
WannabeNewton

2 
213 
I was wondering about how to speed up time because I was bored, so I considered rotating my body clockwise (in the...

Aug2914 09:07 PM
Simon Bridge

10 
285 
It's well understood that extinction effects must be considered when conducting experiments to measure the velocity of...

Aug2914 07:06 AM
DaleSpam

14 
410 
Hello,
I was wondering what the exact definition of conformal transformations is.
This is a question in the...

Aug2914 06:55 AM
haushofer

2 
195 
The subject of Birkhoff's theorem has come up in a number of PF threads, and in the course of researching it for one...

Aug2814 07:06 PM
PeterDonis

0 
203 
If you are standing on the earth and you drop a ball, the ball falls to the ground due to the force of gravity acting...

Aug2814 05:49 PM
my2cts

8 
431 
This old blog entry is being reposted here for archival purposes
because the blog system is being removed.
...

Aug2814 12:14 PM
robphy

0 
178 
Can the above logic be applied to Schw. Metric as well?
Suppose I have an object moving with a radial velocity...

Aug2814 09:12 AM
stevendaryl

11 
260 
...
The other night my telescope buddy and I were discussing gravities vs time over a campfire and beverages.
I...

Aug2814 07:51 AM
ghwellsjr

6 
249 
Hello,
I noticed quite a few questions on the HafeleKeating experiment here, but I believe none that have my exact...

Aug2814 06:23 AM
A.T.

9 
222 
Draft re Ricci vs Riemann tensors
This one is really just the beginning of a musing. I can't even remember if I...

Aug2814 02:54 AM
Markus Hanke

1 
113 
In the Wiki article about the Vaidya metric :
http://en.wikipedia.org/wiki/Vaidya_metric
there is mention of a...

Aug2814 02:45 AM
Markus Hanke

4 
331 
Can you explain please!
thank you.

Aug2814 12:02 AM
Chronos

5 
351 
Hello,
I read in an article that in GR it is possible to use a connection with torsion to model ponctual particle...

Aug2714 03:48 PM
tom.stoer

6 
389 
Here is my basic question:
Lets say we have a massless charged shell with charge q and radius R. Is there some R...

Aug2714 01:06 PM
michael879

35 
4,831 
Hello,
I am trying to understand Kaluza Klein theory on the five dimensional unification. It was mentioned over...

Aug2714 05:47 AM
DaleSpam

1 
218 
I'm seeing examples where for the person in the train the offset of both lights at the end of the train are not seen...

Aug2714 04:59 AM
jebii

6 
227 
hi, I need an explanatory difference between timelike and space like events . examples will do, i know the mathematics...

Aug2714 01:44 AM
Orodruin

3 
173 
Hi
I am in a debate with some creationists. They are claiming that the speed of light changes in strong...

Aug2614 03:42 PM
Drakkith

19 
687 
As far as I have the knowledge of GTR that a mass bends the space time around it.But why does this bend occur?The...

Aug2614 09:03 AM
Simon Bridge

2 
211 
The speed of light is constant in all inertial frames of reference
Imagine a thought experiment, an observer at...

Aug2614 08:24 AM
ghwellsjr

4 
281 
The at rest distance between Betty the astronaut and a flag in open space is 1 unit. If Betty approaches the flag at...

Aug2614 01:29 AM
ghwellsjr

38 
1,326 
In the formula for Christoffel symbols:
\Gammamij= \frac{1}{2}gmkki/∂xj) + (∂gjk/∂xi)  (∂gij/∂xk)
you do sum...

Aug2514 11:35 PM
Matterwave

2 
213 
I've found the equations of motion for a charged test particle in the KerrNewman geometry from a number of sources. ...

Aug2514 02:05 PM
michael879

1 
392 
We know how the curvature of a vector V or a manifold is depicted by the following formula:
dx\mudx\nu\nu , ∇\mu]V...

Aug2514 01:36 PM
stevendaryl

28 
989 
I know that the example of time dilation and length contraction due to Special Relativity is usually given as the...

Aug2514 04:37 AM
PhilDSP

5 
514 
Hi all,
I'm trying to derive that t=δ(t'+vx'/c^2)
Using x'=δ(xvt) then substituting for x=δ(x'+vt') I should...

Aug2414 05:26 PM
Fredrik

7 
293 