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Feb2313 08:40 AM
ZapperZ

1 
42,478 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,134 
Hi does anyone know a formal definition for why off diagonal ricci tensors are equal to zero in a symmetric standard...

Jan2613 05:01 PM
bcrowell

3 
527 
hello,
Please attached snapshot. Does the integral 7.9 equal to 0.5 \inthμσ dzμ/dτ dzσ/dτdτ ?
I'm confused as to...

Jan2613 01:28 PM
Bill_K

1 
665 
I'm trying to wrap my head around what happens as mass is converted to energy. In a nuclear reaction, it is my...

Jan2613 11:35 AM
PeterDonis

14 
1,260 
I just read in a article that NASA has revisited an older theory and found they can improve on it greatly. here is a...

Jan2513 11:21 PM
pervect

2 
997 
since energy absorbed by a BH is no longer available to the universe, why is that not a violation of the principle of...

Jan2513 07:30 PM
PAllen

13 
1,884 
so i am hoping that all of you are familiar with the fact that a basic way of finding the distance between two points...

Jan2513 10:40 AM
Mentz114

6 
886 
In General Relativity (GR), we have the _geodesic deviation equation_ (GDE)
...

Jan2513 10:22 AM
Mentz114

29 
2,610 
I saw this question (in a far removed forum), and I thought it was interesting. Do we have any theoretical reason (or...

Jan2513 05:48 AM
Garth

4 
635 
I am trying to improve my understand of the basic elements of GR.
I have read that the earth orbits the sun because...

Jan2513 02:48 AM
Johninch

25 
2,288 
I'm reading Spacetime and Geometry: An Introduction to General Relativity by Sean M. Carrol and in the chapter on...

Jan2413 10:43 PM
tensor33

6 
1,069 
Can anyone explain proper time with a simple example analogous to real life please? I am having a problem...

Jan2413 05:36 PM
pervect

7 
694 
How can space know how to curve from a black hole.
My understanding is that the no information can escape a black...

Jan2413 01:59 PM
DiracPool

17 
1,349 
Ok so i am aware that if someone manages to travel faster than light, they are technically "travelling through time"...

Jan2413 11:23 AM
ZapperZ

1 
620 
EM radiation seems like a wave traveling through spacetime so, why isn't spacetime the same as ether?

Jan2413 07:25 AM
DaleSpam

1 
432 
Hi,
I've been wondering about this forever and I finally decided to ask on the forums. In relativistic index...

Jan2313 11:38 PM
WannabeNewton

6 
1,104 
According to the special theory of relativity: The combined speed of any object’s motion through space and its motion...

Jan2313 09:47 PM
DaleSpam

11 
2,333 
I know that mass warps spacetime and that's basically the force of gravity (warped spacetime), but why does mass warp...

Jan2313 02:00 PM
Naty1

32 
4,215 
If earth is moving with the speed of 800 km/s in universe, then do we travel at 1/375 of the speed of light according...

Jan2313 12:30 PM
arindamsinha

17 
2,139 
Do the Gravity Probe B results provided by NASA from 2011 support and lean in favor of a 4dimensional everyday world?...

Jan2213 10:26 PM
bcrowell

2 
551 
Earlier today I was on youtube when I saw this comment
I went to respond to this saying that the light would blue...

Jan2213 07:12 PM
PeterDonis

6 
1,083 
An arbitrary Lorentz transformation ##\Lambda## in 1+1 dimensions can be written as
\begin{align}...

Jan2213 05:04 PM
dextercioby

5 
807 
The thought experiment starts with the basic experiment shown here:
...

Jan2213 06:45 AM
soprano

10 
1,858 
Question to the physicists in here:
Would it be possible to spin a metal disk such that it increases mass along the...

Jan2113 07:36 PM
PeterDonis

3 
881 
If you are traveling .6C away from your point of origin and your friend is traveling .6C away from the same point of...

Jan2113 04:05 AM
harrylin

8 
1,091 
Is a negative zerothcomponent of a fourvelocity V^0 with a curved space metric of signature +++ allowed?

Jan2113 03:56 AM
c299792458

2 
859 
I thought about an idea that keeps spinning my head around. It's proven that the faster you move the slower the time...

Jan2013 02:43 PM
SJBauer

21 
1,863 
Hey all! Two things came to my mind about black holes, and I hope some of you can help me out :)
1. Say you have a...

Jan1913 09:01 PM
curiousasker

17 
1,937 
Can the Planck relation, and the Heisenberg and the timeenergy uncertainty principles be derived, or produced, from...

Jan1913 04:22 PM
stevendaryl

13 
1,613 
Hi all,
I'm having a discussion with someone who believes they understand GR, here is their understanding of how...

Jan1913 03:15 PM
A Troubled Man

26 
2,507 
So when a moving object reaches the speed of light time dilates so I assume if an object that has mass somehow...

Jan1913 08:28 AM
PAllen

61 
4,790 
what is the formula of spin connection in GR ?
can we show it in term of structure coefficients ?

Jan1913 04:29 AM
haushofer

10 
2,046 
I know there are quite a few questions about this drive due to the recent news but I have a question that I haven't...

Jan1813 08:41 PM
SJBauer

3 
925 
Well, to start off. I'm in my second year of physics, (honors last year, AP this year) and we haven't talked about any...

Jan1813 07:57 PM
Fredrik

11 
1,352 
This is the barn pole paradox using a slightly curved pole and a silo instead of a perfectly straight pole and doors...

Jan1813 03:17 AM
Sylvia Else

4 
963 
Is there anyone here who could help me understand the state of physicists understanding just prior to 1905 and...

Jan1713 09:39 AM
Thinker007

15 
1,495 
Hi friends,
going through Palatini gravity, I cannot do the variation for palatini f(R) gravity and get to the...

Jan1713 09:37 AM
shadi_s10

7 
803 
Hey all, making my way through Landau and Lifgarbagez classical theory of fields and i had a specific question on the...

Jan1613 08:42 AM
shadi_s10

9 
1,747 
i can't get my head around the twin paradox at all.
so twins A and B move relative to each other and as a result,...

Jan1513 04:07 PM
PeterDonis

16 
1,923 
What is the best software for GR calculations ? GRTensor ?

Jan1513 12:37 PM
bcrowell

6 
1,061 
hi guys, i have a basic question on special relativity.. if the inertial reference frame denotes the frames that holds...

Jan1513 10:09 AM
harrylin

8 
943 