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

Dec3107 02:06 AM
jtbell

0 
37,169 
Before posting anything, please review the Physics Forums Global Guidelines.
If you are seeking help with a...

Feb2313 08:40 AM
ZapperZ

1 
37,413 
I can't figure this out.
Say 2 frames are in relative motion. When the origins at at the same place, 2 lasers shoot...

Oct2113 06:42 PM
ghwellsjr

4 
411 
Suppose we have two equal masses, say at least the mass of our sun separated by a distance of 1 ly and devoid of all...

Dec507 01:31 AM
pervect

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2,913 
Q1 If given a 2D Riemannian space, ds^2 = dx^2 + x^2dy^2, do the componets of the metric tensor are these:
g_11 = 1,...

Nov305 10:59 AM
Jimmy Snyder

6 
1,193 
I'm sorry this could be obvious but i thought I'de ask
ok if 2 objects travailing at 1/2 of the speed of light are...

Oct811 01:28 AM
PAllen

2 
976 
I was reading an article about how two protons have less mass combined than by themselves to make helium, which gives...

Jul611 04:37 AM
Pengwuino

3 
760 
here are two kinda simple questions that I wanted to ask, just to clairify something for me.
1. at the event...

Jun1804 10:05 AM
DW

4 
1,364 
1. In general relativity, why is there a requirement for spacetime, in the context of the Universe, to...

Jul1805 08:02 PM
James R

2 
961 
I have two questions...let's suppose we have a metric in the form:
ds^2 =f(t)dt^2 +g(x)dx^2 +H(y)dy^2
So...

Jul2406 03:04 PM
Parlyne

3 
938 
First, a really basic one: if Jack is jogging past me with a constant speed, and I observe that speed to be v in my...

May2913 10:33 AM
WannabeNewton

7 
520 
If 2 balls or cylinders with watches inside were spun one at close to the speed of light, the other at half the speed...

Aug2310 01:43 AM
yuiop

8 
1,259 
I was just reading the sci.physics.faq http://math.ucr.edu/home/baez/physics/Relativity/SR/rigid_disk.html on the...

Feb2514 02:46 PM
bcrowell

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426 
I started attending to GR lectures, and there we referred to an intelingent beetle living on a 2D flat space and...

Apr1014 10:54 AM
ChrisVer

0 
200 
I am interested in solving the null geodesic between two points in the presence of a gravitational mass, assuming that...

May2609 08:28 AM
atyy

1 
1,292 
Hello all,
I have a 2D Riemann metric tensor with coordinates (x,y) in a halfplane
Infinity < x < Infinity, y >...

Jul1206 01:43 PM
alannb

0 
1,992 
will a 2m(rest length) car moving near lightspeed fall in a 1m hole?

Feb511 07:33 AM
harrylin

11 
1,476 
In the weak field approximation,
g_{\mu\nu}=\eta_{\mu\nu}+h_{\mu\nu}
If we make a coordinate transformation of...

Nov2011 09:37 PM
Sam Gralla

4 
883 
I just a beginner for relativity (both GR & SR), so you find my question may be very simple but still hope you can...

Sep1505 12:16 AM
Berislav

1 
1,229 
Hi,
could someone clarify some concepts and definitions for me, concerning how velocity and acceleration are...

Jul108 07:31 PM
yuiop

10 
2,022 
I'm wondering if the perception of spacetime as "3 dimensions of space and 1 of time" is a symptom of our inability to...

Mar3110 08:31 PM
Frame Dragger

171 
9,881 
Though i've always been familiar with the very (very) basic implications of relativity, I've only just now gone into...

Jun113 01:48 PM
ghwellsjr

6 
523 
Is there any fundamental difference between the 3 dimensions of space that we experience. Such as the difference that...

Jul3108 03:15 AM
CompuChip

1 
1,550 
Hi,
As I understand things we exist on the 'surface' of a 3 sphere of radius R in the context of general...

Oct1105 01:14 AM
robousy

2 
905 
This has to do with the ADM formulation of GR. I am following MTW chapter 21 and Wald appendix E and chapter 10.
...

Mar1212 06:10 PM
Matterwave

12 
1,097 
Today I was conversing online in a gaming community and we began talking about relativity. Eventually we started...

Jan3010 09:10 PM
pervect

5 
1,426 
Hi, Does anyone know of any recently published books that might bring the discussions in "300 Years of Gravitation"...

Mar1510 10:17 PM
atyy

1 
1,051 
I'm working on the decay width of a 3body decay with my professor, I'm stuck and he's not being forthcoming.
...

Aug2510 12:03 PM
mxbob468

0 
1,082 
Hi My name is Pete and this is my first post. I'm a few months away from finishing a degree in mathematics.
I'm...

Sep407 04:43 PM
Petroz

9 
2,175 
P = \left( \begin{array}{c}
E/c
\\ \bar{p}
\end{array}\right)
and
U = \left( \begin{array}{c}

May2312 09:32 AM
bayners123

2 
631 
How to show that the electromagnetic 4 potential is a 4vector?

Feb512 07:03 PM
Simon_G

20 
2,101 
In the wikipedia page a distinction is made in the definition of the SR 4acceleration between the case with...

Jan2014 03:32 PM
TrickyDicky

4 
320 
Consider the thought experiment in the diagram below.
...

Feb1214 05:27 PM
WannabeNewton

12 
682 
A blue guy and a red guy are moving at the same speed in opposite directions with respect to some rest system as...

Sep2911 07:36 PM
bobc2

17 
2,655 
Basic 4 momentum questions. Trying to understand SR a bit better.
Suppose m is non zero for a particle (m being...

Jun1010 05:41 PM
Jerbearrrrrr

7 
901 
2 Weeks ago..i was reading the novel "The time Ships"... by Stephen Baxter (the second part of "the time machine" by...

Aug2206 02:40 PM
pervect

2 
1,402 
Since the "tensors" of relativity are defined with respect to the tangent spaces of a pseudoRiemannian manifold,...

Oct610 10:00 AM
Rasalhague

4 
1,400 
Newton's second law of motion is given in Minkowski space by
\bar{F}=m(c\gamma\dot{\gamma},...

Apr512 12:30 PM
PAllen

1 
980 
Are there names for the Lorentz invariant norm of the fourpotential and fourcurrent? I assume that they are...

Nov2204 02:12 PM
pmb_phy

2 
2,363 
Hi all,
I had a rather poor introduction to special relativity and right now I'm refreshing myself in order to...

Nov2307 07:17 AM
pmb_phy

12 
2,133 
In relativity we have u^\mu u_\mu=c^2, which is just another way of saying that p^\mu p_\mu=m^2c^2 or...

Jan1510 07:08 PM
clem

6 
1,193 
Hey all, my first post here.
Now, Im trying to derive the 4acceleration from the 4velocity by explicitly...

Oct906 02:21 PM
pervect

1 
4,050 