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Feb2313 08:40 AM
ZapperZ

1 
40,421 
The section of the Usenet Physics FAQ titled "Experimental Basis of Special Relativity" has been cited here many...

Dec3107 02:06 AM
jtbell

0 
40,078 
If we drop a charged particle and a neutral particle at the same time(same hight) in a uniform gravitaional field,...

Oct2913 05:17 AM
Bill_K

2 
462 
So for finding the magnitude of a vector, velocity for example, we use v=√(vx2+vy2+vz2), but in special relativity,...

Oct2813 10:27 PM
WannabeNewton

5 
628 
Can we show orthogonality of timelike and null vector?
http://u1310.hizliresim.com/1g/x/u0rkg.png

Oct2813 05:23 PM
nomather1471

7 
636 
I was thinking about one of the many resolutions of the socalled 'twin paradox' within SR framework. I realize many...

Oct2713 11:38 PM
adrian_m

13 
892 
Am I right in thinking that any bit of mass, eg. me, or my spoon, or a planet, can never not be moving? And also as...

Oct2713 05:31 PM
Simon Bridge

6 
610 
Hello all. When light goes through one medium to another, its velocity and wavelength change but frequency remains the...

Oct2713 02:44 PM
Nugso

13 
1,286 
Hello all,
In Carroll's there is a brief mention of how to get an idea about the curvature tensor using two...

Oct2713 01:47 PM
victorvmotti

3 
755 
This is a spin off from another thread:
First there are a couple of mathpages...

Oct2713 01:10 PM
yuiop

5 
733 
EDIT: Figured out question, don't worry guys.

Oct2713 10:01 AM
Nugatory

1 
418 
Let's tie a rope on an object, then we swing the object around in a circle, then we start running forwards while...

Oct2713 07:07 AM
DaleSpam

66 
8,652 
I keep getting the terms confused:
1) if I have the equation
Δr2+c2Δt2=s2
does one say that I am using the...

Oct2713 02:57 AM
nomadreid

3 
530 
Hello everyone,
One of the conclusions of relativity is that no massive object can move at v ≥ c, but with respect...

Oct2713 12:28 AM
ViolentCorpse

15 
2,134 
If an electron orbital the earth only influence by gravity,does it emit electromagnetic waves? if so, the radius will...

Oct2613 04:23 PM
WannabeNewton

5 
628 
I have red only about a few experiments conducted to detect the speed of light using interference pattern.
but i need...

Oct2613 01:01 PM
ghwellsjr

14 
832 
Hello,
First off, I'm not a physics student by any means, but it does intrigue me. I've been wondering about the...

Oct2413 11:02 PM
nitsuj

47 
8,561 
How does one change the dot product such that there is no dot product in between, just plain multiplication? For...

Oct2413 04:30 PM
Chestermiller

3 
460 
Given that molecules, atoms, protons, and neutrons are overwhelmingly space (i assume quarks and electrons are more...

Oct2413 11:48 AM
nitsuj

6 
777 
I have been reading an introductory book to General Relativity by H Hobson. I have been following it step by step and...

Oct2413 02:36 AM
Halaaku

9 
719 
Assumptions:
1] I'm an observer at inertial rest
2] Light is going c
3] Gravitational interaction can't exceed c...

Oct2313 03:29 PM
bahamagreen

12 
815 
Consider a spaceship and a source, with no relative motion but spatially separated. At t=0, spaceship moves with...

Oct2313 12:59 PM
pervect

21 
1,365 
Picture a perfectly aligned row of pool balls all touching each other that was 200,000 miles long. If the first ball...

Oct2313 08:07 AM
DaleSpam

14 
2,151 
A and B leave from a common point and travel in opposite directions with
relative speed v. When B’s clock shows that...

Oct2313 06:20 AM
stevendaryl

1 
691 
Assume you have observer #1 who emits one photon (can that even be done?) and an observer #2 who zips (at .01 c...

Oct2213 05:54 AM
ghwellsjr

7 
703 
Is it possible for parts of GR and SR to be wrong even thought there are things about them that seem to be undeniable?

Oct2113 09:56 PM
DaleSpam

1 
484 
I can't figure this out.
Say 2 frames are in relative motion. When the origins at at the same place, 2 lasers shoot...

Oct2113 06:42 PM
ghwellsjr

4 
485 
Imaging at a Trillion Frame Per Second  Ramesh Raskar
...

Oct2113 03:07 PM
A.T.

3 
540 
Bill and Ben are a fixed distance from each other.
Bill sends a laser pulse to Ben and times how long it takes to get...

Oct2113 03:01 PM
A.T.

18 
1,124 
Einstein's field equations are time invariant.
So is it conceivable that a reverse black hole can exist i.e a "white...

Oct2113 07:49 AM
PeterDonis

11 
5,802 
Would the spin of a particle be measured the same by any set of observers upon that strip?
Would an observer...

Oct2113 05:02 AM
haael

1 
520 
i am trying to understand the relationship between the two on a local and global scale and how these two concepts are...

Oct2013 09:24 PM
WannabeNewton

5 
675 
I was curious about the use of relativity in GNSS (GPS) systems (since I only know very basic relativity but I...

Oct2013 06:10 PM
PeterDonis

8 
959 
This is an analysis of how a classic Einstein light clock behaves when accelerated orthogonal to its main axis. The...

Oct2013 06:09 PM
yuiop

53 
21,030 
Bear with me, assuming you had a device that could bend spacetime the same way as energy does and built two time...

Oct2013 11:55 AM
mfb

1 
493 
I am reading the draft of a paper written by someone whose native language was not English and so who might not have...

Oct2013 09:08 AM
yuiop

4 
479 
The ladder paradox can be resolved when considering the relativity of simultaneity. However, wouldn't the problem be...

Oct2013 03:29 AM
ghwellsjr

3 
704 
Hi,
I've been reading about fourvectors and I have two quick questions:
If the position 4vector is timelike,...

Oct2013 01:22 AM
BruceW

15 
1,084 
If a distant observer were to observe a large cube made of strong material approach a black hole, what would he see?
...

Oct1913 05:10 PM
WannabeNewton

12 
813 
Given a curve c(τ) with tangent vector V, a vector field X is parallel transported along c if
\nabla_V X=0
at...

Oct1913 04:18 PM
Bill_K

3 
615 
Hi,
I have been pondering a special relativity question about the concept of simultaneity when moving at speed of...

Oct1913 03:34 PM
Guybrush

4 
515 
We can write the geodesic condition as
\frac{d^2...

Oct1913 03:20 PM
pellman

5 
686 