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Feb2313 08:40 AM
ZapperZ

1 
42,428 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,075 
If you can "catch up" to the light reflected from the Earth at that time in the past. What kind of resolution would...

Aug1314 03:13 AM
Gerinski

4 
405 
When you have a general coordinate chart on spacetime you have a lot of freedom to pick your coordinates, but you are...

Aug1214 07:03 PM
Fredrik

1 
216 
The Riemann curvature of a unit sphere is sinesquared theta, where theta is the usual azimuthal angle in spherical ...

Aug1214 04:16 PM
pervect

13 
351 
When neglecting gravity and body size, if a body rotating at uniform angular velocity about a central body sends a...

Aug1214 01:49 AM
HALON

3 
292 
if we know
K^{a b}= (∇^a*ζ^b ∇^b*ζ^a)/2,
ζ is a killing vector,
under the variation of metric g_{a b}→g_{a...

Aug1114 05:34 PM
WannabeNewton

6 
472 
In Carroll's we read
...The Unruh effect teaches us the most important lesson of Quantum Field Theory (QFT) in...

Aug1114 03:38 PM
Matterwave

1 
287 
I was looking up ways to solve the Einstein field equations when I came across a couple of sources.
...

Aug1114 08:20 AM
robphy

2 
308 
I am pretty sure this question must have been asked before... However I was always wondering, what would a theory be...

Aug1014 06:45 PM
ChrisVer

3 
382 
Two spaceships approach an observer from an equal distance and from an opposite direction with an equal speed in the...

Aug1014 08:08 AM
Nugatory

2 
381 
This is a conceptual problem, right out of a book.
Say Mavis is moving in a spaceship at 0.6c relative to Stanley on...

Aug1014 02:47 AM
ghwellsjr

11 
425 
Theoretical question.... If an extremely long object approached the event horizon, let’s say a torpedo shaped craft 1...

Aug914 07:11 PM
pervect

6 
362 
Why photons can't go any slower than the speed of light, in vacuum? Or if they could, then why they don't?

Aug914 03:41 PM
DaleSpam

74 
1,716 
Dear all,
I was reading this...

Aug914 03:04 PM
dextercioby

2 
207 
If you have two counterrotating streams of particles traveling at near luminal velocity then is there effective...

Aug914 10:25 AM
jtbell

4 
368 
I have a little bit confuse on the Simultaneity
I know if there are 2 coordinates. One coordinate S' is moving V...

Aug914 09:57 AM
ghwellsjr

6 
449 
Recent data in qm suggest black holes could decompress into a white hole on either our universe or another as such is...

Aug814 11:42 PM
PeterDonis

1 
311 
I'm sure that most people on these forums are familiar with the similarities between compressible flow in aerodynamics...

Aug814 12:27 PM
jlefevre76

6 
575 
I have question on my own understanding.. So please correct me..
1. It is said that mass of photon is zero; Or it...

Aug814 10:29 AM
jlefevre76

24 
1,134 
The free field EinsteinMaxwell action is often states as
$$S =  \frac{1}{4}\int_M F^{\mu \nu} F_{\mu \nu}d^4 x +...

Aug714 11:24 PM
Matterwave

1 
296 
Ok, so if I were to travel towards a black hole at close to c, would the event horizon become visible?
Let us...

Aug714 01:31 PM
tionis

41 
1,442 
hi, i am stucked with a confusion about michelsonmorley experiment. I am not going into mathemtaical detail, the...

Aug714 01:37 AM
ghwellsjr

15 
457 
Meter sticks laid out around the rim of a rotating disk will foreshorten by the Lorentz factor. This means more of...

Aug614 10:10 AM
WannabeNewton

8 
405 
Consider two equal and opposite charges moving in the same direction and velocity v0, and are separated a distance R. ...

Aug614 04:07 AM
KatamariDamacy

13 
463 
Basically I am trying to lorentz transform the magnetic field along θ of a bunch particles which have a gaussian...

Aug614 03:12 AM
matt_crouch

4 
290 
Hi all,
I am really curious about the final state conjecture in general relativity, but I don't really understand...

Aug514 03:36 PM
bcrowell

2 
273 
http://i57.tinypic.com/2j5n9s4.jpg
We’ve all seen this little fellas up there. Two brothers, twins, in their 60’s....

Aug514 07:34 AM
DaleSpam

3 
312 
when muons are created in the atmosphere and fall to earth the earth clock runs faster. Thus, the "slower" muon clock...

Aug414 10:08 PM
PAllen

2 
216 
Do experiments like 1971's Hafele & Keating show that SR relativistic effects of time dilation are not mere products...

Aug414 03:50 AM
pervect

16 
877 
Hello everybody. I was recently brainstorming ways to make the Einstein field equations a little easier to solve (as...

Aug314 09:01 PM
Nugatory

3 
280 
Hi all,
I was thinking about special relativity and spacetime and had the thought of measuring our velocity with...

Aug314 08:59 PM
Matterwave

8 
443 
I understood that the basic idea of the MichelsonMorley experiment was to measure the velocity of light, as seen from...

Aug314 11:18 AM
ghwellsjr

4 
427 
Ok so I read this on another site... "the Milky Way is part of the Local Group...The Local Group is calculated to move...

Aug314 02:42 AM
sublime56

9 
481 
Hi
Just wondering about the orbital path of a high speed particle  eg electron in orbit. Is it length contracted?...

Aug214 11:24 PM
jartsa

3 
346 
Hi
I have a new formula (or at least I think it's new) for predicting the wavelengths/frequencies of hydrogen's...

Aug214 03:35 PM
DaleSpam

1 
352 
I was thinking a bit earlier:
What if you created a particle at infinity (ignore the normal particle rules for...

Aug114 10:43 PM
pervect

2 
264 
I recognize the analytical usefulness of having time, a parameter. However, does time really exist? If so, is there a...

Aug114 11:37 AM
ChrisVer

21 
644 
Considering that speed of light is constant and finite, then why are the time dilatation and length contraction...

Aug114 10:16 AM
tonyxon22

6 
356 
We know that distant galaxies (which are expanding) are sometimes expanding at rates that do not conform with our...

Aug114 08:22 AM
Drakkith

2 
258 
From my understanding and from what I have read Quantum Mechanics and Relativity do not mix well. I understand that...

Jul3114 10:37 PM
WannabeNewton

3 
318 
This may be a stupid question, but have the various gravitational wave observatories around the world been tested by...

Jul3114 03:42 PM
PeterDonis

2 
223 