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

Dec3107 02:06 AM
jtbell

0 
41,133 
Before posting anything, please review the Physics Forums Global Guidelines.
If you are seeking help with a...

Feb2313 08:40 AM
ZapperZ

1 
41,503 
I'd like to start by mentioning that I have very little in the way of experience on the subject, so forgive me if my...

Jan1511 09:23 PM
JesseM

11 
1,473 
Why must the 4momentum for photons p^\mu =(\frac{h\nu}{c},\frac{h\nu}{c} \textbf{e}) transform as a 4vector in...

Jan1611 02:09 PM
CompuChip

2 
1,041 
I'm not very fund of the subject, but what i know is that the Schwarzschild metric and other known solutions for...

Jan1611 03:09 PM
atyy

4 
920 
If gravity and acceleration are "cousins," How much faster does time proceed on Earth than floating motionless (or...

Jan1611 08:21 PM
poeteye

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2,562 
I am confused with some of the aspects of time dilation. I read the derivation (the one with the mirrors) and I...

Jan1611 11:08 PM
merry

10 
2,275 
I was reading in a paper for Chamseddine the following:
"In the past many attempts were made to construct
gravity...

Jan1711 05:04 AM
haushofer

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2,449 
This is a two part question. Part 1: I am embarrassed to ask but if someone could please help me. I was thinking about...

Jan1711 10:10 AM
JesseM

23 
2,826 
Hi
I tried using the search function but it keeps timing out on me. Anyway I'm trying to find a good description...

Jan1711 04:59 PM
jason12345

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7,928 
Is it
\nabla_\mu\nabla_\nu A^\alpha={A^\alpha}_{;\mu\nu}
or
\nabla_\mu\nabla_\nu...

Jan1711 10:32 PM
pellman

3 
1,425 
Hi,
Is Spacetime inside the Quantum Vacuum or is the Quantum Vacuum inside or fill up Spacetime?

Jan1811 12:25 AM
Alfrez

2 
824 
Ok so in Einstein's thought experiment with the train, everything makes sense except...
Einstein is stating that an...

Jan1811 08:29 AM
JesseM

7 
1,044 
What are the symmetries determined by FRW spacetime? I guess they include Lorentz symmetry, rotationally and...

Jan1811 01:58 PM
Ich

6 
2,461 
In the LHC, what radial and tangential Gforces does a proton experience where from start to finish? Where would each...

Jan1811 03:10 PM
teve

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997 
To travel by space ship to Andromeda (2.5 million light years) within a life time (say 50 years) you would have to...

Jan1811 03:39 PM
Nabeshin

8 
3,186 
if light can be affected by gravity then why is it said to have no mass? and sience light is affected by gravity.. if...

Jan1911 05:57 AM
DaleSpam

46 
6,840 
I'm a little confused about what an observer would see while watching something fall into a black hole.
From what...

Jan1911 06:39 AM
lavinia

24 
3,042 
Hello. When one is converting between coordinate systems, the Jacobian arises as a necessary consequence of the...

Jan1911 10:20 AM
bcrowell

2 
1,700 
Folks, apologies for reviving a thread that I know has been picked over, but I am a bit confused.
I understand the...

Jan1911 10:26 AM
JesseM

20 
2,485 
i have read quite a bit about gravity waves, and even worked (as a lab tech) on an early GW experiment at LSU back in...

Jan1911 04:36 PM
Naty1

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734 
when we say "a topological action", do we only mean that the action is metric free? or is there some other meaning for...

Jan1911 04:46 PM
Naty1

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2,079 
1. What are the value of physics constant in Kerr metric, including G, M, c, a, r, or others?
I expect to...

Jan2011 02:01 AM
stevebd1

2 
1,158 
Is there such an animal as an energy continuity equation, or one involving Pmu or the stress energy tensor?
It...

Jan2011 04:09 AM
Phrak

2 
1,824 
Hello PF Folks.
So Einsteins Special Thoery of Relativity is based upon two principles (im shortening them for...

Jan2011 09:28 AM
roineust

23 
4,035 
If we rearrange Einstein's massenergy equivallency equation we get.
m=\frac{E\sqrt{1\beta^{2}}}{c^{2}}
A...

Jan2011 01:19 PM
Mueiz

8 
1,442 
What do we mean by "Time is elastic"?
How can we see that time is elastic? Is there anyway to illustrate this?

Jan2011 08:48 PM
BigBang1234

5 
1,633 
Suppose we are looking from an inertial frame at two events in a region of spacetime.
The first event A (0,0,0,0) is...

Jan2111 01:52 AM
JesseM

22 
2,053 
I understand that the distance between 2 points in 2 dimensions
sqrt(x^2 + y^2)
and in 3 dimensions it's
sqrt(x^2 +...

Jan2111 03:12 AM
K^2

4 
1,150 
I'm confused about how photons are able to split into electrons and positrons. Learning about four dimensional...

Jan2111 08:17 AM
DaleSpam

4 
1,186 
let's say a train is traveling at relativistic speed along a straight line to right, and a man is standing in the...

Jan2111 09:05 AM
ghwellsjr

3 
1,006 
Probably this has an easy answer but I can't see it just now, according to the principle of relativity we shouldn't be...

Jan2111 10:52 AM
TrickyDicky

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2,172 
We have talked about black hole, Unruh and cosmological horizons in these forums....I am wondering if a simple...

Jan2111 11:18 AM
Qreeus

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4,513 
I'm having a bit of a debate on travelling to AC. I was wondering if someone can post calculatons to show how long it...

Jan2111 01:34 PM
JesseM

17 
2,708 
Hi all!
I was browsing Wikipedia when I came upon the following article:
...

Jan2111 03:23 PM
nismaratwork

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840 
Hi guys!
I was reviewing some basic stuff in Special Relativity, specifically the part where it can be proven that a...

Jan2211 01:25 PM
arestes

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1,829 
Very quick question here thats bugging me.
I go to the LHC and send a proton around at 0.999999991c. After 5...

Jan2211 03:30 PM
=Red=

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964 
Well the other day I was thinking about the speed of light and how physics says that nothing can go above the speed of...

Jan2311 03:13 AM
GrayGhost

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2,828 
The existence of singularities in the form of black holes as predicted by GR is universally accepted at this point.
...

Jan2311 11:08 AM
atyy

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1,771 
What is the purpose of MichelsonMorley Experiment?
Why it is called the failed experiment? what is the contradiction...

Jan2311 02:46 PM
abrowaqas

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5,292 
Hi, I asked a theoretical question here a month or two ago and someone was able to help me. I have another:
Imagine...

Jan2411 07:53 AM
bobc2

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1,619 
If the equivalence principle is true then it means that the Earth's gravity field is a constantly accelerating frame...

Jan2411 10:41 AM
nismaratwork

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7,102 