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

Feb2313 08:40 AM
ZapperZ

1 
42,469 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,118 
Suppose we have a box at rest that is filled with a uniform gas. We denote the volume by V and the pressure by p....

Jun108 12:18 PM
pmb_phy

89 
13,323 
If we add a third observer to the twins paradox at the turnaround point (at rest with earth), and with a clock that...

Jun108 06:22 AM
Al68

4 
1,301 
I have ben doing some reading on general relativity but I can not find an answer to my question.
If a curved 2D...

Jun108 02:38 AM
gravity guru

6 
1,486 
general relativity says that gravity and acceleration produce the same effects but when an object accelerates its...

May3108 04:29 PM
yuiop

22 
2,610 
Simple question (derived from some unanswered posts from various posters, mostly mitesh9)...
Two identical clocks A...

May3108 08:51 AM
yuiop

96 
8,524 
Apparently a moving rod shrinks. What are the measurements of two moving parallel train tracks?(2 vertical tracks...

May3108 06:03 AM
Doc Al

1 
921 
I'm new to educating my self on this field by reading..but i have a question.
if you are approaching the speed of...

May3008 09:43 PM
CJames

13 
2,290 
According to the Wikpedia entry
http://en.wikipedia.org/wiki/Bell's_spaceship_paradox
and this paper...

May3008 06:14 PM
Wizardsblade

104 
13,244 
Andromeda Paradox

May3008 12:36 PM
paw

1 
1,647 
Suppose one twin travel to a distance L and turn around, another twin travel to a distance L/2 and turn around. When...

May3008 10:16 AM
kahoomann

12 
2,098 
Prove that 4 vector potential does really a 4 vector? Most of the textbooks I found only mention that divergence of 4...

May2908 09:33 AM
pmb_phy

59 
13,721 
any body can give me some material about Palatini forms of GR please, thank you!

May2908 05:18 AM
xiaomaclever

0 
1,069 
From Bergmann chapter 8.Please show that (see at Fig. below)....thank you.

May2908 03:54 AM
supakorn

3 
1,158 
Hi,
I understand that EM fields have energy and they travel at c. Light is an EM field so it travels at c as well....

May2808 11:39 PM
worwhite

9 
1,219 
Can someone tell me how much does a light ray bend when it passes over the surface of the densest star known?
Is...

May2808 05:16 PM
Ulysees

2 
4,681 
Please tell me if it is possible to derive the formula which accounts for the Lorentz contraction from the invariance...

May2808 12:19 PM
DrGreg

30 
8,698 
Quite often the explanation to the twins paradox is stated as acceleration breaks the symmetry or one twin feels...

May2808 11:12 AM
RandallB

63 
5,771 
Hi All,
Can someone tell me what is meant by time & space being "continuous" as opposed to "discontinuous"? What...

May2808 07:09 AM
flatguy

13 
4,496 
This is still rather new to me so please pardon my ignorance. My introduction to tensor differentiation involved only...

May2808 04:46 AM
snoopies622

12 
4,742 
If I want to consider the velocity of distant receding galaxies which may be receding at velocities close to the speed...

May2708 11:08 PM
duordi

6 
1,325 
I have been roaming around threads on PF and there are certain things on which there is no consensus. I would...

May2708 03:07 PM
RandallB

21 
2,485 
Based on the quote below and the link to Wikipedia, I believe the implication is that gravitational redshift will...

May2708 11:11 AM
mysearch

70 
7,955 
Can a 4dimensional manifold with the Schwarzschild metric be embedded into a flat manifold of 5 (or more if...

May2708 10:14 AM
shoehorn

14 
1,974 
Hey I have done a few google searches, and I do not have a relativity book to let me know what the equation for time...

May2708 10:09 AM
shalayka

12 
2,507 
Is there any free online tutorial which completely explains General Relativity without concept of Tensors?

May2708 09:22 AM
pmb_phy

2 
3,755 
Trying to understand black holes as much as possible without the difficult math....
I gather that matter  or...

May2708 04:26 AM
HarryWertM

0 
1,030 
1. How would a general relativist explain why an object falls towards the earth?
2. Is it correct to say that it is...

May2708 04:22 AM
cristo

4 
1,430 
This is related to this thread here. To make responding easier, I have marked questions in red. I have tried to...

May2708 02:00 AM
neopolitan

8 
1,912 
I'm curious about how people here view Einstein's prescription for determining simultaneity in an inertial frame, and...

May2708 12:26 AM
Ken G

152 
17,542 
Since SR physics has considered motion strictly as the separation of bodies,
no longer can a body move through space...

May2608 07:48 PM
Chrisc

45 
3,046 
Hi,
I am not exactly sure how to present this question. Even thinking about it creates some confusion,so I will...

May2608 07:18 PM
tinytim

1 
4,703 
(This is probably answered somewhere, but I couldn't find it, I'm kinda new. >_>)
So, say I was able to travel at...

May2508 04:26 PM
pmb_phy

9 
3,980 
What is the meaning of the curvature scalar (R) in GR? More precisely, what is the meaning of it's evolution? Why when...

May2508 04:02 PM
pmb_phy

11 
2,778 
Doran/Lasenby define a proper interval as:
\delta \tau = \int \sqrt{\frac{dx}{d\lambda} \cdot...

May2508 11:13 AM
Peeter

8 
2,372 
Hello.
If you were far away from a small black hole, and shot (for the sake of argument a bullet) with such precision...

May2508 10:51 AM
Jorrie

12 
2,174 
relativity
LC=length contracted or length contraction
TD=time dilated or time dilation
LOS=loss of simultaneity ...

May2508 01:28 AM
granpa

0 
1,369 
We know what is twin paradox is, and also why it is not a paradox, but my question is, "if we can not define absolute...

May2408 10:16 PM
Al68

124 
10,045 
The wavefrequency relationship is as follows:
f = v / \lambda
Therefore:
v = \lambda * f
The de Broglie...

May2408 10:16 AM
lbrits

8 
1,471 
suppose we have a stationary observer 'A' at the origin. at t=0 rockets 'B' and 'C' pass the origin moving at...

May2408 08:50 AM
DaleSpam

1 
1,110 
(This could be a dumb question, but in any case I'll be happy if the answer is simple)
I understood that the path...

May2408 05:51 AM
jostpuur

3 
1,185 