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

Feb2313 08:40 AM
ZapperZ

1 
42,731 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,375 
I'm slightly confused as to how we can use the picture of a 2D surface embedded in 3D space as an analogue to...

Sep1411 03:15 AM
A.T.

2 
963 
Hey there guys I just have a question to ask some of you. Given the occurence of time dilation being related to an...

Sep1311 04:45 PM
nordqvist11

4 
1,336 
Does that mean the spaceship has become bigger or denser up to the subatomic level? Or is it just more atoms have...

Sep1311 03:23 PM
richerrich

3 
1,267 
If an object's mass increases as it nears the speed of light, would its gravitational field also change, and therefore...

Sep1311 02:39 PM
PAllen

2 
936 
in http://www.youtube.com/watch?v=6vdXlwDRRR8
at 0:47:00 Susskind begins discussing accelerated reference frames...

Sep1311 11:05 AM
bahamagreen

14 
1,846 
does a person feel weightlessness or any differences when he make a free fall under gravity of different values say...

Sep1311 07:26 AM
DaleSpam

10 
1,971 
We know that in GR it is not possible for arbitrary spacetimes to define a conserved energy by using a 3integral....

Sep1311 06:11 AM
tom.stoer

23 
2,469 
So of you may have heard of this expierament back in 2000,Does the expierament send something back in time even though...

Sep1311 04:30 AM
byron178

0 
962 
As I understood,GR says that mass and energy change the form of spacetime and when other masses move near that...

Sep1311 03:21 AM
A.T.

8 
1,263 
Gravity around star is often depicted as the curvature if spacetime or a 'dimple" in a flat sheet.
What would...

Sep1211 04:47 PM
pervect

27 
2,747 
It is common knowledge that of the classical tests of GR, gravitational redshift is normally considered to be testing...

Sep1211 10:48 AM
PeterDonis

10 
1,339 
Does anyone know how the progress is on the attempts to detect gravitational waves with interferometry?
As far as I...

Sep1211 09:29 AM
Agerhell

2 
853 
a relativistically moving body passes through much more field energy than a slow moving body per unit time. Does all...

Sep1211 08:18 AM
Naty1

3 
774 
I haven't learnt much of advanced mathematics. It seems that we can use metric tensors to lower or raise index of...

Sep1111 11:30 PM
atyy

15 
2,737 
Regarding the observer riding on the middle of the train sees the light strike first the fwd first and then the aft....

Sep1111 10:33 PM
bahamagreen

16 
1,773 
Please bring me out of my state of confusion if I need to be... The question is how to calculate the rate of an atomic...

Sep1111 02:28 PM
pervect

8 
1,293 
A bus travels at a very high speed. It's time slows down.
What's the mechanism by which this happens?
Any help...

Sep1111 06:52 AM
HallsofIvy

4 
1,673 
Does anybody know about a comprehensive list of cosmological models and their properties? E.g. FRW, dS, AdS, ......

Sep1111 05:54 AM
Mentz114

1 
1,141 
Have gravitational waves been directly detected yet?

Sep1111 03:08 AM
ZealScience

2 
576 
Hi,
Please consider:
At time zero a spaceship takes off from earth and keeps traveling under constant...

Sep1011 07:13 PM
Janus

3 
1,099 
In special relativity we have the velocity 'u', being the difference in speed between two objects, from which we work...

Sep1011 04:12 PM
Dizzle

0 
928 
as i read in the brief history of time "let a plane be moving straight in 3d world but we see it in a curved path on...

Sep1011 11:36 AM
DaleSpam

4 
1,173 
I was sitting in my bed thinking about how time can be relative after i heard about those experiments with atomic...

Sep1011 11:10 AM
PAllen

8 
2,267 
Fast question :I noticed that often the EFE are presented without the minus sign in the source term, (G=kT instead of...

Sep1011 10:34 AM
yenchin

4 
957 
An observer far away from an event horizon never sees a particle cross the event horizon. How does this effect the...

Sep1011 09:43 AM
debojoti

13 
13,672 
It is said that at low speeds the relativistic kinetic energy formula will give you the same answers as the classical...

Sep1011 06:45 AM
DrStupid

16 
4,663 
When looking at earths ability to curve spacetime; how far does these curves go? can they theoretically be registered...

Sep911 02:53 PM
Fredrik

4 
1,803 
Sorry if this is a noob question or if it has been answered before or if I'm just misunderstanding the physics...

Sep911 06:29 AM
BruceW

3 
849 
Been a while since I posted here. I gave up on pursuing a career in engineering or physics so forgive me for any...

Sep811 10:14 PM
Drakkith

22 
4,946 
Hey guys,
I'm just wondering what the general opinion is of these two articles:
...

Sep811 08:14 PM
bobc2

3 
776 
This is my first post here,
Consider the typical simultaneity scenario:
An observer `O' right in the middle of...

Sep811 06:23 PM
PeterDonis

5 
1,034 
It is widely recognized in physics textbooks that Planck constant is a "universal constant". But I nerver see a proof....

Sep811 01:02 PM
DaleSpam

170 
19,811 
I've read a newspaper article which claims: "If the search for gravitational waves succeeds, then Einstein's theory of...

Sep811 12:59 PM
debojoti

3 
958 
hello,
in Penrose diagrams it says that once you have crossed a first Cauchy horizon(of a rotating black hole) ,...

Sep811 06:43 AM
YogSothoth

11 
2,665 
How do you prove that for the schwarzschild metric,
ds^2 =...

Sep811 03:44 AM
Identity

0 
488 
I am a noob! Forgive me if it sounds too stupid!
Let me say, I am in CERN right now at the LHC.
I fire a proton...

Sep811 02:27 AM
Pengwuino

1 
787 
I've been reading up on gravity probe B and the results, but I have a question about precession in general  I've...

Sep811 02:26 AM
DrDu

2 
676 
Hello,
I was talking with my Physics professor the other day about something I could do in Special Relativity,...

Sep711 11:04 AM
Mordred

11 
1,687 
What are the difference between Einstein's General Relativity and Wheeler's Geometrodynamics,or they are the same...

Sep711 06:12 AM
martinbn

3 
952 
I have been reading about Thomas precession and have encountered many papers that appear to give conflicting accounts...

Sep611 10:12 AM
jason12345

6 
2,288 