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Let's say the two ends A and B of a wormhole are moving relative to one another.

If I stick a starship halfway into end A of the wormhole, does the part of the starship that sticks out of end B move along with end B, or does it remain stationary with respect to end A?

Assuming it does move, will a force be exerted on it if end B of the wormhole for some reason suddenly accelerates or decelerates?

python dude
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    Nobody in science can tell you what happens when you send a non-existent starship trough non-existent wormholes. For that you need a science fiction writer. – CuriousOne May 19 '15 at 22:44
  • @CuriousOne And yet Einstein described what happens to a non-existent twin traveling on a non-existent relativistically accelerating starship. He called it a thought experiment rather than science fiction. What happens to an extended object moving through a wormhole is a valid question in GR since it does allow wormholes. – Conifold May 20 '15 at 00:30
  • @Conifold: Einstein described a real world effect that can be seen in virtually every high energy physics experiment made since the 1930s or so. He also didn't work from an imagined scenario but he solved a problem relating to "the electrodynamics of moving bodies". If you read the second part of the paper, you will see what the real physical motivation for it is. It's not twins traveling in spaceships (or on trains). Einstein solved an experimental riddle that had existed for 20 years or so at the time he wrote the paper. Wormholes are not such a problem. – CuriousOne May 20 '15 at 00:58
  • @CuriousOne Einstein 1911:"If we placed a living organism in a box ... one could arrange that the organism, after any arbitrary lengthy flight, could be returned to its original spot in a scarcely altered condition, while corresponding organisms which had remained in their original positions had already long since given way to new generations." And Einstein worked from imagined scenarios quite often, equivalence principle came from another one. Wormholes are a useful imagined scenario that tests the predictions of GR, and it is analyzed by many experts including Hawking. – Conifold May 20 '15 at 02:34
  • @Conifold: Einstein liked to play with Gedankenexperiments (which are simply meant to explain an idea, they are not replacing actual experiments) while he solved real physical problems. Wormholes are neither. They are not even a physical solution to the equations of GR and that puts them squarely in the fiction wing of the library. – CuriousOne May 20 '15 at 02:42
  • @CuriousOne There is no coherent definition of what is or isn't a "physical solution" to GR, it is examples like these that help figure it out. And gedankenexperiments are often meant to do just that, explore theory's limitations by looking at extreme cases. Black holes were theoretically explored long before they were discovered, and they were discovered because their effects on surroundings were known theoretically. And you don't know if physical wormholes exist, because nobody does. So they may well be both. But even purely mathematical wormholes in GR would not be "in the fiction wing". – Conifold May 20 '15 at 03:30
  • @Conifold: To the best of my knowledge stable wormholes have been buried even theoretically a couple decades ago and I am not aware that there is any serious astronomical search going on for them. You are welcome to give me citations for such a search, if you know about one. In physics we never decide anything by Gedankenexperiment by definition, otherwise a couple ten thousand people who are operating CERN right now are utterly superfluous and should be laid off immediately. Anyway, I am not going to get you to read the definition of science, again, so we might as well stop here. – CuriousOne May 20 '15 at 03:40
  • @CuriousOne What was buried a decade ago is the "energy conditions", the ones used to rule out wormholes earlier http://arxiv.org/pdf/gr-qc/0205066.pdf "Wormholes are science fiction", wrong. "Einstein didn't work imagined scenarios", wrong. "Gedankenexperiments simply explain ideas", wrong again. "In physics we never", please, I suppose string theorists should all be laid off too. The rest is demagoguery. Here is a simpler face saving solution: delete your comments. – Conifold May 20 '15 at 04:07
  • @Conifol: So to you asking for an actual search for a hypothetically postulated physical object is demagoguery? :-) – CuriousOne May 20 '15 at 04:33
  • @CuriousOne No, but claiming that a theoretical object is science fiction unless it is actively searched for, like right now, is. So are "real physical motivation", "real physical problems", "not even a physical solution", "utterly superfluous... ten thousand people", the royal "we in physics", "you are welcome to give me citations" (while providing none), "read the definition of science", and other rhetorical bs to paper over the lack of arguments. :-) – Conifold May 20 '15 at 05:25
  • @Conifold: So what do I have to search for to find a wormhole? Is it a black hole that doesn't get any more massive even though matter is falling in? Is it a black hole that is getting lighter? What are we looking for in a hypothetical real search? What does the theory say about the mass distribution of these objects? These are easy to answer questions for someone who knows what wormholes have to look like, right? – CuriousOne May 20 '15 at 05:36
  • Guys, relax! No need to argue this much over a question that was closed as duplicate anyway :-) – python dude May 20 '15 at 06:34
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    Hi python dude, I was merely demonstrating what the "little" scientific problems are when someone starts talking about unidentified physical objects (aka UPO's). :-) – CuriousOne May 20 '15 at 06:42

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