Faster than the speed of light (pulling on a string)?

AI Thread Summary
Pulling on a string connected between two stars does not result in instantaneous movement at the other end; instead, the signal travels at the speed of sound through the material of the string. The string's inherent stretchiness means that any change in tension propagates at this slower speed, not faster than light. This concept has been discussed extensively in various forums, indicating a common misunderstanding about the nature of such interactions. The FAQ linked in the discussion provides further clarification on this topic. Thus, the idea of faster-than-light communication through a string is incorrect.
Ozs
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If you were to connect a string from one star to another (assuming everything remains still), and then you were to pull one side of the string towards you, the other would be pulled immediately, thus the "communication" between the two edges is technically faster than the speed of light? Does this make sense?
 
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Ozs said:
If you were to connect a string from one star to another (assuming everything remains still), and then you were to pull one side of the string towards you, the other would be pulled immediately, thus the "communication" between the two edges is technically faster than the speed of light? Does this make sense?
No, not immediately and not even at speed of light. It occurs at the speed of sound. You will find probably dozens of threads on PF here, which deal with this idea.
 
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The other end wouldn't get pulled immediately, because the string has a certain amount of "stretchiness" to it. So, when you pull your end, the string will stretch a bit and that extension will travel down the string at approximately the speed of sound in the string.
 
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Ozs said:
If you were to connect a string from one star to another (assuming everything remains still), and then you were to pull one side of the string towards you, the other would be pulled immediately, thus the "communication" between the two edges is technically faster than the speed of light? Does this make sense?

This type of question has been asked so many times, there is a FAQ on it:

https://www.physicsforums.com/insights/can-i-send-a-signal-faster-than-light-by-pushing-a-rigid-rod/

Zz.
 
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The link to the FAQ should take care of the OP's question. Thread is closed.
 
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