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

Feb2313 08:40 AM
ZapperZ

1 
42,480 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
42,138 
Here's a scenario I thought of a few days ago. I know there must be an easy explanation, but it hasn't come to me ......

Nov2404 01:46 PM
PBRMEASAP

2 
1,035 
http://www.physorg.com/news67773542.html

May2506 03:22 PM
scott1

0 
1,035 
Why the physicists studying a "AdS black hole"?
what is the meaning of AdS (Anti de Sitter) for black hole? and...

Jun1808 12:43 AM
supakorn

2 
1,035 
I've always thought that understanding at a profound level requires real precision in the use of language. I was...

Jan1010 01:25 PM
LAncienne

0 
1,035 
In my cosmology lectures they say that a negative curvature gives an infinite space but I was thinking what about the...

Feb1910 07:06 AM
George Jones

3 
1,035 
I just finished watching a hawkins program about time travel that theorized that the faster an object travels through...

Aug2810 08:18 AM
Mentz114

1 
1,035 
When an object moves in curved spacetime, how does its angular momentum vector transform? My hunch is that the...

Oct1010 03:12 PM
pervect

2 
1,035 
What do you think of the article published in the "European Physical Journal D" with the title:
"The quantum vacuum...

Mar2813 07:24 AM
Vanadium 50

6 
1,035 
So, this has really stirred my interest. To be clear, I'm not citing these as sources, simply linking for discussion;...

Jun1214 07:37 PM
Simon Bridge

9 
1,035 
i strongly suspect that there is mathematical constraint on space time whicg is differensiable function ofmetrics and...

Jun2804 08:06 AM
einstein_vishnu

0 
1,034 
I am rather confused with General Relativities explanation of Gravity!...

Apr2805 01:15 PM
pervect

6 
1,034 
Perhaps it is a stupid question, but really confuses me.
In QFT, virtual particles can be produced from vacuum, say,...

Jun2705 02:58 PM
hellfire

1 
1,034 
If i have two fish in a fish tank say fish A and fish B and the owner of the tank is looking into the tank
each...

Apr2008 03:17 PM
russ_watters

3 
1,034 
Say we have dust filled universe. At some instant of time this universe has a mass density rho, and it evolves with...

Dec2109 08:20 PM
George Jones

2 
1,034 
As something approaches the speed of light the objects relative mass is increasing.
When the relatvie mass is...

Jan1410 04:52 AM
Dmitry67

5 
1,034 
Hi,
I'm not a physicist and my idea of relativity is limited by wiki... but I have one question...
If I sit with...

May212 01:09 PM
HallsofIvy

7 
1,034 
A thought occurred to me when reading the Encarta article on relativity:
Now, it occurs to me that the velocity...

May404 08:44 PM
turin

8 
1,033 
Does the theory of relativity include angular motion? Say we have one body synchronously orbiting a motionless body....

Sep508 06:41 AM
DrGreg

3 
1,033 
My question is, which photon is the one that first hits the square in the following example
If I had a large...

Jan1110 07:35 PM
Zula110100100

5 
1,033 
Hey, I'm stuck on part of the calculation for the compton wavelength. Basically, my notes go:
Energy of Electron
...

Feb1410 03:53 PM
jtbell

8 
1,033 
Lets say we emit a photon from the ground out towards the sky , and as the photon travels away from earth it gets...

Jul810 05:45 PM
cragar

12 
1,033 
Hi all.
Suppose we have two objects A and B, and suppose we tie a rope R to the objects with the rope R's two edges...

Jun1911 09:30 PM
DaveC426913

5 
1,033 
The time dilation formula:
\Delta t'=\frac{\Delta t}{\sqrt{1\frac{v²}{c²}}}
says that the closer you come to the...

Jul1511 12:58 PM
Jaynte

3 
1,033 
i constantly feel that newton was right in measuring the relative velocity.einstein makes use of light which has a...

Aug2211 02:32 AM
harrylin

2 
1,033 
Has any experiments been done equal to this scenerio where the twin leaving earth and seeing earth time dilated.. but...

Dec2912 11:02 AM
ghwellsjr

7 
1,033 
Dear Friends,
Discussion of the Einstein's Special Relativity clock paradox is often complicated by the role of...

Jul413 11:50 AM
ghwellsjr

8 
1,033 
It is often said that we basically live in the past, since it takes time for light to travel from objects to our eyes...

Jun1014 12:40 PM
pervect

35 
1,033 
HI guys first post :cool:
I need to show that
B^2E^2/C^2 is invariant under Lorentz transformation (E and B...

Apr3004 09:31 AM
DW

6 
1,032 
Baez gave fine presentation of general relativity: http://www.math.ucr.edu/home/baez/einstein/einstein.pdf
I wish...

Jul2108 09:29 AM
exponent137

0 
1,032 
Why no FAQ for the Twin Paradox?
There are a few topics for which a FAQ would be very useful. I'd suggest that the...

Jun209 09:48 AM
DaleSpam

2 
1,032 
As long as there is any energy/mass at all in our universe, time will always be in a "slowed" state. So, let's say we...

Feb2611 03:42 AM
John232

9 
1,032 
Studying the movement of a particle on bound orbits around a black hole I found a fact that seemed a little strange...

Jul1613 07:17 PM
pervect

11 
1,031 
as a warning, my knowledge of physics is purely on the level of 'mild interest'. Any innacuracies/stupidities in the...

Jan1805 06:47 AM
hazhar

2 
1,031 
Hey, I was reading through a few of these posts, and something crossed my mind:
Say there was a space ship...

Nov1705 03:17 PM
JesseM

10 
1,031 
Okay, I realize that there are difficulties in combining the theory of GR and quantum mechanics, but I thought SR and...

Oct2906 04:41 PM
robphy

2 
1,031 
so, a bit of confusion here  suppose i have a spaceship that can acheive 0.99999C, and i decide to go to a star that...

Aug210 04:22 PM
Doc Al

6 
1,031 
A thought experiment:
Say that you and I decide we are going to go into orbit around a black hole. I am brave and you...

Oct510 07:58 PM
PAllen

1 
1,031 
hi
if gravity is a force of attraction ,a natural question arises ,why it can't be repulsive?as there is a great...

Mar1911 07:55 PM
rchase

9 
1,031 
I am steadily working my way through D'Inverno and have reached Chapter 20. On page 272 there is a problem which goes...

Nov2212 12:35 PM
TerryW

3 
1,031 
We have two clocks within a laboratory.
We put one on the table and the other in a centrifuge made of glass so we can...

Apr2213 05:45 PM
pervect

5 
1,031 