19-05-2004 00:08									#121
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quote: Originally posted by Jamski However, according to both the SToR and the GToR, time travel of a sort is possible by travelling fast enough though our 3 dimensions. The fact that time is passing more slowly the faster you travel is a proven scientific fact. Unfortunately it only works one way (i.e. you can get to the future quicker by flying in orbit at near light speeds) and is of no practical use.

Ah, the story of twins. One stays on Earth, and the second boards a spaceship and goes travel the university at high speed for one subjective year. When he comes back, local time at Earth has passed eg 80 years and his brother is dead.
However doesn't this theory overlook that speed is AFAIK a measurement of movement relative to another location. For example a spaceship moving away from Earth at high speed. But couldn't one just reverse the situation and claim the Earth is moving away from the spaceship at high speed, and therefore say that local time on Earth will have passed only one year, while in the spaceship of that twin time will have passed 80 years??

	19-05-2004 00:21									#122
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The key here is that the twin brother has to come back to earth. Before they meet (or supposed to meet) again time is normal to each of them in their own relative frame (or whatever the English word for it). But when the twin brother come back to his brother's relative frame, the earth, it is appearant that it is the spaceship that had travelled at high speed.

	19-05-2004 00:21									#123
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It is relative to another location, but not relative to the starting location. You need a third location to determine that, and that can be any star.

	19-05-2004 01:04									#124
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I recommend you all to read some of Isaac Asimov's books.

	19-05-2004 01:17									#125
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I have the whole Robots and the empire series. I only read it half though. I will catch on it when I finish Man in the High Castle

	19-05-2004 01:24									#126
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quote: Originally posted by HongHu I recommend you all to read some of Isaac Asimov's books.

Already finished those about a decade ago (and reread some).

But for novels about one-way time travel, try 'The Peace War' or 'Realtime' from Vernor Vince.

	19-05-2004 01:35									#127
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About a decade ago, I was still in prime school . Currently I like reading books based upon alternative histories (as some may guessed).

	19-05-2004 01:46									#128
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That was no reason to read at all! Admit it, you were just plain lazy...

	19-05-2004 01:46									#129
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Nice thread

Can I reccommed "The Dispossed" by Ursula Le Guin. Its kind of at a tangent to the discussion, as the main character is a physicist working on FTL travel, but the book is actually about the ideal of the communist utopia.

-Jam

	19-05-2004 01:49									#130
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I know the writer, but that book I haven't found, I think. Is it 'The Dispossed' or 'The Disposed'?

	19-05-2004 01:53									#131
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Dispossessed. They have nothing. They have lost all their possessions.

-Jam

	19-05-2004 01:53									#132
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Ok here. Mr Tompkins in Wonderland by George Gamow. Everybody can benefit from some dreams about time travel and stuff during a really long and boring lecture.

	19-05-2004 01:55									#133
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quote: Originally posted by GeoModder That was no reason to read at all! Admit it, you were just plain lazy...

No, I was reading other things. Like Clarke.

	19-05-2004 02:02									#134
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Go on the lookout for M. K. Wren (The Phoenix Rebellion, a trilogy), I can recommend it with your next faction in mind. Ruling aristocratic famillies with a forced 'reusable' worldview within a medieval classlike society.

	19-05-2004 02:03									#135
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I'm reading (and rereading) Agatha Christie and Sidney Sheldon myself. They have pretty good English grammars. (Just to get us back on topic. )

	19-05-2004 02:05									#136
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Stop HongHu! This has finally become a really useful thread to everyone.

	19-05-2004 02:07									#137
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* GeoModder edited this post...



for the hidden message...

Last edited by GeoModder on 19-05-2004 at 02:13

	19-05-2004 02:10									#138
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Don`t do it! ...... Fool! You have no idea what you have just set in motion here. You have just ensured destruction of your world.

	19-05-2004 02:16									#139
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Who me? Ok I'll stop. Ok I have stopped. I'm not going to do it.

Phew so close.

	19-05-2004 02:20									#140
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Not you! Geo has almost set the ultimat evil in motion.

To get back to previous topic: anyone read that book, how is it named: Light of other days by Clarke and another writer whose name I cannot remember at the moment

	19-05-2004 04:26									#141
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Wow Just happened on this thread because of (atm) lack of posting elsewhere.

1 First: Yes the English of non native speakers at 'Poly' is excellent: Take Kassi for example.

2 Jamski's avatar. I can understand the reference to music (that's Mahler isn't it) but the nodding sheep, I don't get. (I presume there is nothing (terribly) ontoward).

3 Time Travel:As S. Hawkins postulates It could only happen when we build a time machine. You could only travel back to the year when it first became possible to travel in time at all. A bit like the PSI gate.

Hey and the 'Back to the Future' series was not bad on logic

	19-05-2004 04:53									#142
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quote: Originally posted by HongHu The key here is that the twin brother has to come back to earth. Before they meet (or supposed to meet) again time is normal to each of them in their own relative frame (or whatever the English word for it). But when the twin brother come back to his brother's relative frame, the earth, it is appearant that it is the spaceship that had travelled at high speed.

Why is that apparent? Why can't you say the Earth was travelling at high speed relative to the spaceship?

quote: Originally posted by obstructor It is relative to another location, but not relative to the starting location. You need a third location to determine that, and that can be any star.

But the spaceship, the Earth and the stars are constantly moving "through space". Heck, AFAIK space itself bends along with massive objects. So I wonder: when looking at the larger picture, does "starting location" really have any meaning in a non-Euclidian universe?

	19-05-2004 04:58									#143
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quote: Originally posted by HongHu I recommend you all to read some of Isaac Asimov's books.

The robot novels and short stories are the best. Foundation started off pretty good but the ending wasn't great.

	19-05-2004 05:17									#144
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This was a very very odd thread

	19-05-2004 05:52									#145
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Don't look at me!

	19-05-2004 06:40									#146
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This thread is like chain reaction

	19-05-2004 08:28									#147
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Or how ones thought goes from one place to another. But yes Kody gets the credit for threadjacking.

quote: Originally posted by Maniac Why is that apparent? Why can't you say the Earth was travelling at high speed relative to the spaceship?

Because when he came back to the earth the relative reference frame again became the earth.

Strange thing is that if the brother that stayed on earth actually stepped on the spaceship to meet his brother when earth meets spaceship again, theorectically it should be that he is the younger one because from the relative frame of spaceship it is him and the earth that went for high speed travel. How come he never lived long enough for the spaceship to come back?

	19-05-2004 11:11									#148
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An accelerating frame of reference is unsuitable to apply the laws of special relativity.

If a spaceship goes away and then comes back, it had to do some accelerating.

	19-05-2004 12:22									#149
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quote: Strange thing is that if the brother that stayed on earth actually stepped on the spaceship to meet his brother when earth meets spaceship again, theorectically it should be that he is the younger one because from the relative frame of spaceship it is him and the earth that went for high speed travel. How come he never lived long enough for the spaceship to come back?

We don't know why! But it works! Many experiments have been done with two identical watches and moderatly fast rocket travel (most famously during the moon expeditions) and every time the watch that had flown to the moon and back had less elapsed time than the one that remained on Earth.

Physics at a high level ceases to be logical.

-Jam

	19-05-2004 12:55									#150
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quote: Physics at a high level ceases to be logical.

Maybe they are physics no more?

Regarding those post bout Isaac Asimov - have read much of him too, especially I liked that story where a robot (AI) logically proved that there is God, that humans as lesser beings as him couldnt have created him so there's certainly some higher being(-s)...
When looking at humans situation is very similar - they didnt believe that they have been monkeys once because monkeys are lesser beings and thus a higher being was needed to create humans..

Maybe the whole concept that lesser beings cant create higher ones is wrong?

Im certain it is!