There is no condradiction at all
It is just our common sense which refuse to accept this claim

Clocks are alwayes non syncronized even when B is on flight

Suppose that B is travelling at 50 % of speed light
A and B can comunicate via radio msg's

A says

" You must reach waypoint P(x,y,z) at time T "
if B take the figures as they are he will miss the target
He must turn the figures into his " B's time / space frame "
Not only
If A says
"You must reach waypoint P(x,y,z)"

To us it makes sense but not for the pilot
B would not know where to go to

A must comunicate also the Time !

In the theory of relativity time and space can not be split

The concept of "contemporaneity" has been banned
It does not make any sense to claim

" If the time on earth is...then the time on board..."

The famous equation

Tb = K Ta

with k = 1/sqrt((1 - (v/c)^2)

it does not give the time on board (tb) given the time on the earth(Ta), as many people assume
Tb is the time on board in the " A's space/time frame "

The only thing in common between A and B is the so called "Interval" which is a mix of space and time

I = SQRT(T^2 -L^2) the formula contains also the light speed "c"

If you still think that "turning" is the solution, borrow 3 syncronyzed atomic clocks
One in Berlin, one In Hamburg, one for you
Buy a one way ticket
You will see that your own atomic clock will be some milli seconds late

P.S

Many years ago I made an animation in visula basic 6.0 , using the simple equations of the special relativity, to show how the two observers, in relative motion, describe the same event : an explosion of a super nova
It is rather easy to create but it was quite interesting , at least for those strange guys who are interested in such stuff

I read an article written by Penrose himself , a couple of years ago, but I dont remember the details
I must read it again

A-choo!


Would be great if you could find more details about it, since I do find the question interesting, though it appears to be "little more" (not saying that its trivial) than relativistic addition of velocities applied to light emitted from several points of an object.
Sadly, I don't have any time right now to read such things

Got what. I understand both problem and solution and I'm sure that I'm right, because countless books cover this topic and all agree with me, not you.
I UNDERSTAND special relativity, my common sense sees no contradiction in my sentence. A ages slower in B's frame, B ages slower in A's frame is totally true during flight. However, if both are back to earth ONE of them MUST be the older one. There is absolutely no way that this could still hold when they're both at the same position.


I don't understand you. It might be me but I really have a hard time following your arguments, they sound wishy-washy to me.


Don't make the experiment more complicated than it is. Radio messages travel at the speed of light. What's the problem with the concept of a REST FRAME?


Not really. A spatial coordinate can be Lorentz-transformed without knowledge of time. Of course it has to be communicated if he has to meet the target in a given time span, and of course he has to transform it then, but that's nothing new.
You always make it sound like we'd be doubting relativity. We're not. I'm quite convinced Error has no problem with it, either.


It does make sense if you give the rest frame as information, as I always do. Funny enough, YOU don't do that. I cite: "Clocks are alwayes non syncronized even when B is on flight". In which frame? Or later: "One in Berlin, one In Hamburg". How are they synchronized?
You are missing so much information in your arguments that your explanations simply do not satisfy me.


great you've noticed.


that's a 4-vector contracted to itself. what has that to do with them? Why do A and B have that in common?


http://en.wikipedia.org/wiki/Twin_paradox
http://physics123.net/2009/02/the-twin-paradox-explained/
http://www.einsteins-theory-of-relativity-4engineers.com/twin-paradox-graphical-solution.html
http://www.iep.utm.edu/time-sup/#H17
...
they ALL agree with ME. Find me only ONE article which supports your idea, until then, I will see this discussion as finished.

Joey.

PS: I don't want to sound rude, but honestly, have you ever discussed like that with your physics professor?

Joey, you might have missed (it was easy in the rush of posts a few pages back) an interesting question Joozey asked:



I consider that an interesting new topic, and certainly a discussion that is now more fruitful to discuss then to continue to beat the twin-paradox-horse

If you find the time, I'd be interested in your opinion on that as well.
Though I do assume that it might already be pretty much solved with Terrell-rotation. Still, you're knowledgable on the subject, so I'd like to hear what you think and if maybe I missed something.

Yup, I have no "problems" with relativity ~ I may not be able to fully calculate whatever I want in general relativity, but I do think that I have grasped the fundamentals.

Nope that's why I removed it...you were faster than light

But I think that also joey should remove something, dont you agree ?

And then, something mysterious happened... causing me to keep my promise.

EDIT: Joey? Pardon my language, but I guess he was just a bit pissed off when he wrote the reply - given the length of it and the time you edited, I suppose he saw the earlier version. It might not be the way a gentleman handles things, but I suppose one can understand why he was pissed in the first place. But now that you've corrected your post, it'd only be fair if he now, in turn, removes the little stitches, too...

But then, there's a good reason I'm not a moderator. I guess in the end, we all should just really start to grow up, get a thicker skin, and not get angry at things written by people on the internet.

EDIT EDIT: I'd hate for this to seem like I've been picking sides. Because I don't want this, because I don't feel like I can do this in a fair way. The reason for this simply being the different context and native languages we all have - Joey and me are both german, but I suppose you aren't, Alberto? Since customs and way of speaking can vary alot in different languages, I might just be more sensitive for one type of "insult" over the other. So in essence, I'd really prefer to not say anything definite.

[ Surprisingly, we haven't been asked yet to do someones physics- and/or math-homework yet. Is that a sign of maturity of the schoolkids these days... or just a sign that we're coming across like we have no clue!? ]

What's going on? Who has edited which posts?
I don't want to change my post, that's not the way I write in these forums. Don't take the "great, you've noticed" too serious, though, as I said. I'm sure you know what you talk about. I just don't understand your point. Still, if you could give me a reference, an article or whatever, then maybe I'll understand.

Anyway, Error, it seems as if you're even more knowledgeable on that topic than me. Terrell-rotation? Never heard of that ^^. Have you read that article? That's some weird stuff. I also found that:
http://www.youtube.com/watch?v=JQnHTKZBTI4
sounds quite interesting, although the term "rotation" somehow seems misleading if you ask me. When the sign bends its tip is farther away from your position (obviously), so light will travel longer to your eye from that position. As the middle part is nearer to you, it also seems as if you've passed that part a bit more than the tip. I'm not sure, though, if that accounts for the whole effect.

I'd rather not know what they think of me

Edit: And btw I think we're far calmer than the average forum these days. What's going on in these hiring threads?

Do not discuss about things which you do not know nothing about. I see when someone speaks angry, because then he makes mistakes. And there are many mistakes in your posts (in this guy's there are more, though - reread it and you'll see).

Concerning your discussion, I have read some books on this topic and I have the following conclusion. Consider moving fast.

The red color, being on the lower half of the spectrum then is slower to your eyes. Question: in which direction does the observer move in these pictures?

Not convinced? Imagine your eye being a telescope. Then

the light always moves 'inside' your eyeball, like that. Since your eyeball is not a flat surface (how that would look like - ahahaha) there is great distortion - this also explanes the Terell rotation effect (in parts).

AdrenalinMod

@Error: I'm so jealous of you. How can you stay so settled when the crap meter goes crazy all around you?