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How long is a piece of string?

  1. Dec 8, 2011 #1
    I know the conventional way to answer this question is to measure its length in cm.

    But then I thought everything is relative to another thing so the length of the piece of string is X cm relative to me but what if you zoom in on a section of string and measure the twists and turns... Then go further until you reach the atomic level.

    Is it possible to zoom in further and further? Is there a limit you reach until you can't go any smaller? If so, why was the limit that size and what caused it?

    I know mathamaticians consider a piece of string infinite in length but why doesn't it appear infinite to us? Is it because everything is relative? So if I was a microbe on that string all I would see theoretically is string... So maybe we exist on a piece of string much smaller than the microbe.

    So maybe it's possible to zoom in an infinite distance until you reach a limit that's infinitely large like another universe that exists on that piece of string...

    Why is it only strings that can be infinite? Why can't a piece of hair? a watch or piece of chicken?

    I'm confused!
  2. jcsd
  3. Dec 8, 2011 #2

    Doc Al

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    Staff: Mentor

    They do?
  4. Dec 8, 2011 #3


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    definately some strange assumptions there

    I cant really see how zooming in on it would make any difference to how long it is
    take a piece of string 1mm thick and 1metre (1000mm) long
    for arguement sake lets say for that diameter and length it takes 1 billion atoms
    zooming in on a microscopic scale isnt going to make any difference ... its still going to be 1 billion atoms from end to end

    and by that reasoning, it doesnt matter what the material is, a bit of string, a hair, a length of metal.... It has a finite size cuz it has a finite number of atoms making it up

  5. Dec 8, 2011 #4
    I think he has fractal geometry in mind- like measuring the length of a coastline at different scales. Zooming in would reveal more twists, humps, crinkles, etc. And if one were dealing with a purely idealized mathematical object that was self-similar at every scale, then it would be infinite in length. However, it is a physical object and there is a limit at the atomic scale.
  6. Dec 8, 2011 #5
    It's exactly twice the distance from one end to the middle.
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