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Registered Member #193
Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022
With the same acceleration he would follow the same trajectory; acceleration is a vector quantity The same magnitude of acceleration would be an interesting question and I guess that's what you mean. It's an interesting question to which I don't know the answer but I guess that since the acceleration averages to zero (if he's accelerating South now then in half a revoultion's time he will be accelerating North) the time dilation will also average to zero.
Vigilatny Registered Member #17
Joined: Thu Feb 02 2006, 02:47PM
Location: NL
Posts: 158
Bored Chemist wrote ...
With the same acceleration he would follow the same trajectory; acceleration is a vector quantity The same magnitude of acceleration would be an interesting question and I guess that's what you mean. It's an interesting question to which I don't know the answer but I guess that since the acceleration averages to zero (if he's accelerating South now then in half a revoultion's time he will be accelerating North) the time dilation will also average to zero.
The time dilation does not depend on the direction, only the magnitude.
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
There is a clock postulate that says that the time is unaffected by acceleration and it is supported by particle experiments. That would mean that time is affected by the relative speed change that may be a result of acceleration(s) but not affected by acceleration itself.
As I understand it the clock postulate can't be proved or disproved by special or general relativity.
Registered Member #187
Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140
This is my personal opinion only, so please don't flame me.
I don't believe in the twin paradox. Something tells me that we are trying to interpret reality based on visual observation, which goes completely out the window when you start talking about travelling at the speed of light.
You cannot use visual observation to determine what is really happening. You must treat the matter as though you are blind, otherwise what is observed visually will drastically complicate and confuse the matter. Who cares what things look like at these speeds, what matters is what happens when your eyes are closed. If you want to discuss bizarre visual phenomena, then that is another matter altogether, and should be treated as a visual phenomenon ONLY.
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
Numerical abstraction aside, mixing Newton and Einstein is not a good idea. You may end up overcomplicating something simple or oversimplifying something complex.
If you were alluding to the popular theoretical loophole that allows time-travel buy using a black hole? Although mathematically plausible it has nothing to do with centrifuges and does not necessarily have to be related to Kerr hole like structures (science fiction fans always like this one.)
Not to mention this thread may disappear into a black hole even if the subject was tactfully approached.
""too much mathematics" to understand the universe?" Bah ha ha ha lol -- That’s the funniest thing I heard today... Descarte cursed many generations with the notion that a few lines on a page can plot all vector spaces. He was wrong about many things, but made numerous contributions to mathematics.
"Just because you can’t see it does not mean it isn’t there."
Registered Member #32
Joined: Sat Feb 04 2006, 08:58AM
Location: Australia
Posts: 549
Bored Chemist wrote ...
"Remember that velocity is relative and there is no absolute reference point in space. So how can you say that it is twin 1 who nears the speed of light and not twin 2?" Because he is the one who gets pushed back in his seat by the rocket's acceleration. The 2 twins undergo different experiences and these different experiences have different outcomes. Where's the paradox?
BC, read my post more carefully and you'll see that that question was rhetorical and I gave it more or less the same answer as you did. I finished it off by saying that since acceleration is significant, special relativity isn't valid.
wrote ...
Given that all motion is relative you can't say which twin stayed still. from that point of view a skeptic might say "How come it's the correct twin that ages; you can't say which one moved?" With no acceleration that would be a true paradox. On the other hand only one of them actually gets in the rocket and gets accelerated- that's why his time "slows down" compared to the other.
As I said, it's an almost true answer, since it takes general relativity to see what happens to the twin who accelerates.
This is closely related to something that confused me before I studied relativity in physics. If motion is relative, how can you ever say whose time slows down in normal situations without acceleration?
Say I travel from near Earth to Jupiter at relativistic speed and Eve is watching me. We're both timing. Who measures the longer time? The key is to think about it in terms of time between events. The first event is being near Earth, the second is being at Jupiter. From my point of view, both happened at the same place (I'm still sitting in my spaceship). For Eve, one was near and one far. That's the difference.
Registered Member #193
Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022
"I don't believe in the twin paradox. " If you are prepared to think of 2 atomic clocks as twins then the"paradox" has been demonstrated. One clock really does run slow.
Registered Member #29
Joined: Fri Feb 03 2006, 09:00AM
Location: Hasselt, Belgium
Posts: 500
Clocks also run ever-so-slightly faster on the surface of the earth than in space. For example, GPS signals must take this into account, as well as the motion of its satellites, if errors are not to accumulate over time in the timing of its signals.
The resolution of the twin paradox lies indeed in who "feels" the acceleration (i.e. jumps from one inertial frame to another).. See the "adventure of Terence and Stella."
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