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Feb2313 08:40 AM
ZapperZ

1 
41,528 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
41,160 
Do all massless particles travel away from you at the speed of light regardless of you speed . i know light does ,...

Nov2609 12:16 AM
cragar

4 
1,212 
A Lorentz boost along the x axis conserves area in the xt plane. Can anyone think of an argument to prove this fact...

Nov2509 04:22 PM
bcrowell

44 
3,724 
Wald says (paraphrased)
"Let us attempt to destroy a black hole and create a naked singularity. KerrNewman black...

Nov2409 03:38 PM
lark

0 
772 
According to Wikipedia:
Objects and radiation can also escape from the ergosphere. In fact the Penrose process...

Nov2409 03:37 PM
Frame Dragger

6 
2,175 
Hi all!!
Anyone knows where to find, online or on a book, the affine connection for the schwarzschild metric?
Thanks

Nov2409 08:40 AM
alle.fabbri

5 
2,050 
Hi everyone,
I'm trying to work through section 86 of Landau and Lifgarbagez volume 2 (The Classical Theory of...

Nov2409 06:03 AM
lalbatros

4 
2,590 
I don't understand why this happens. And it's not enough to tell me 'well it happens because Simultaneity is...

Nov2409 03:20 AM
A.T.

15 
2,755 
Einstein proposed a very simple derivation to E=mc^2 in 1940s which is wellknown as Einstein’s box and a brief...

Nov2309 10:21 PM
DaleSpam

10 
1,263 
If we have a tank which full of water.Then,emitted the light into the tank.The speed of light is c/n . If we can run...

Nov2309 10:20 PM
IPhO' 2008

7 
1,090 
When we use the Lorentz transform. We must have S,S' frame.
How can we choose S,S' frame?

Nov2309 10:16 AM
atyy

6 
1,028 
A and B are twins,A notice B moving away from him with velocity v, so A notice that B is youngerv than him (time...

Nov2309 09:19 AM
HallsofIvy

3 
946 
Why the speed of light decreases when it is in the medium?
Thank you.

Nov2309 08:21 AM
jtbell

1 
979 
In quantum mechanics, the phase velocity is f/k=E/p because of E=hf and p=hk where k=1/wavelength.
In special...

Nov2309 03:19 AM
clamtrox

14 
2,934 
If Einstein's box (http://galileo.phys.virginia.edu/classes/252/mass_and_energy.html ) is full of phonons instead of...

Nov2309 12:19 AM
sunroof

4 
1,399 
In the classical wave theory, the formula of Doppler effect is f ' = f (1+V/u) where u is the light speed. In vacuum,...

Nov2209 08:23 PM
sunroof

0 
1,112 
Hi,
the theory of relativities second postulate is:
The speed of light in a vacuum is the same for all...

Nov2209 11:49 AM
Paul77

17 
2,346 
From my reading of introductory texts on special relativity, I've seen this defined in various ways, and I'm curious...

Nov2209 08:19 AM
Rasalhague

8 
4,572 
With blackhole and hawking radiation's help, i come up with an idea to convert my apple completely into pure energy...

Nov2109 11:37 PM
magnetar

3 
1,574 
This may be farfetched, but please try to bear with me.
I will try to apply my existing knowledge of fields to...

Nov2109 07:02 PM
espen180

0 
826 
What should an ancient old nonmathematical fossil do when trying to understand GR? I'm reading "Gravity" by Shutz,...

Nov2109 06:27 PM
atyy

5 
842 
types of metrics 5d in that einstein tensor is diagonal????
i need a metric 5d in that G_{00}=G_{11}=G_{22}=G_{33}...

Nov2109 05:53 PM
alejandrito29

0 
1,038 
To a moderator: this is a theoretical, conceptbased question.
Say two balls of putty, moving relativistically...

Nov2109 05:03 PM
DaleSpam

3 
1,451 
There's a video camera at a railway station. It can see the driver in the front of a fast moving train going past in...

Nov2109 01:53 PM
YellowTaxi

0 
891 
The experiment showing that, time is relative, and how it changes with velocity and gravity. Einstein's twin...

Nov2109 09:41 AM
russ_watters

44 
4,948 
Hi all,
I m not a physicist but a biological oceanographer. I would like to know how should I consider spacetime...

Nov2109 08:31 AM
A.T.

1 
833 
looking at this thread,
Has einsteins experient with time been proven, why hasn't it been applied or used ( 1 2 3) ...

Nov2109 12:11 AM
ensabah6

0 
2,536 
The gravitational shift of a photon in vacuum df/f=gH/c^2 had been confirmed by Pound and Rebca in 1960s. As to sound...

Nov2009 07:22 PM
sunroof

0 
1,173 
the metric is ds^2=f(x,y)(dx^2+dy^2)+dz^2dt^2
G_{tt}=G_{zz}=\frac{1}{2f(x,y)}\nabla^2(ln(f(x,y)))
the energy...

Nov2009 06:46 PM
alejandrito29

0 
527 
So, for example, 2 objects are moving towards each other.
There is a frame where 2 object move with (for the sake of...

Nov2009 12:38 PM
jtbell

1 
629 
Suppose there is a square mass object in the universe (I know its impossible, but suppose...).
Does spacetime will...

Nov2009 08:43 AM
hamilton00989

3 
847 
I do aware that it is impossible to be in a frame with C velocity.
But suppose I could ride a photon (suppose)....

Nov2009 06:46 AM
DaleSpam

3 
1,241 
Can anyone answer this?
GPS satellites are preprogrammed before launch due to relativistic effects mainly time...

Nov1909 11:32 PM
yogi

119 
10,745 
I hope I can explain my question clearly enough for someone to answer.
Suppose we wish to estimate the power...

Nov1909 08:12 PM
qraal

3 
4,254 
I would appreciate any insight into these questions; I have had a little EM but no general relativity. Maybe general...

Nov1909 04:19 PM
yuiop

1 
1,054 
The electromagnetic energy density is welldefined through the square of the Maxwell Field tensor. Why cannot such a...

Nov1909 01:46 PM
ringerha

7 
1,532 
I did a thought experiment for myself today to test whether energy is conserved in Lorentz transformations.
I chose...

Nov1909 12:05 PM
espen180

4 
948 
The resonating frequency of a series LC circuit is given by:
f=(c/2πn)
This frequency measured in a moving frame is...

Nov1909 06:41 AM
DaleSpam

15 
1,441 
This question was asked by a friend recently, and I couldn't give an answer!
To an observer on the Earth, when...

Nov1909 02:32 AM
jambaugh

17 
3,746 
Can anybody provide me with a link to a REAL life experiment (a credible source, and not a thought experiment. )...

Nov1809 08:48 PM
crx

4 
876 
i am read a paper of name: "formalism for an extended object"(in spanish)..
a sub manifold of coordinates y^i...

Nov1809 05:11 PM
alejandrito29

2 
787 