Bootstrap paradox

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Pigeon
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Bootstrap paradox

Post by Pigeon » Wed Mar 21, 2012 6:02 pm

The bootstrap paradox is a paradox of time travel in which information or objects can exist without having been created. After information or an object is sent back in time, it is recovered in the present and becomes the very object/information that was initially brought back in time in the first place.

Numerous science fiction stories are based on this paradox, which has also been the subject of serious physics articles.

The term "bootstrap paradox" refers to the expression "pulling yourself up by your bootstraps"; the use of the term for the time-travel paradox was popularized by Robert A. Heinlein's story By His Bootstraps (see below).
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Definition

Because of the possibility of influencing the past while time traveling, one way of explaining why history does not change is to posit that these changes already are contained self-consistently in the past timeline. A time traveler attempting to alter the past in this model, intentionally or not, would only be fulfilling his or her role in creating history, not changing it. The Novikov self-consistency principle proposes that contradictory causal loops cannot form, but that consistent ones can.

However, a scenario can occur where items or information are passed from the future to the past, which then become the same items or information that are subsequently passed back. This not only creates a loop, but a situation where these items have no discernible origin. Physical items are even more problematic than pieces of information, since they should ordinarily age and increase in entropy according to the Second law of thermodynamics. But if they age by any nonzero amount at each cycle, they cannot be the same item to be sent back in time, creating a contradiction.

Another problem is the "reverse grandfather paradox", where whatever is sent to the past allows the time travel in the first place (such as saving your past self's life, or sending vital information about the time travel mechanism).

The paradox raises the ontological questions of where, when and by whom the items were created or the information derived. Time loop logic operates on similar principles, sending the solutions to computation problems back in time to be checked for correctness without ever being computed "originally".

Example from fiction

The term bootstrap paradox comes from Robert A. Heinlein's story "By His Bootstraps", in which the protagonist is asked to go through a time portal by a mysterious stranger, a second stranger tries to stop him, and all three get into a fight which results in the protagonist being pushed through anyway. Ultimately, it is revealed that all three are the same person: the first visitor is his future self and the second an even older future self trying to prevent the loop from occurring. The bootstrap paradox here is in where and how the loop started in the first place.


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Royal
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Re: Bootstrap paradox

Post by Royal » Thu Mar 22, 2012 3:44 am

This is an ab flex for the brain.

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Pana
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Re: Bootstrap paradox

Post by Pana » Thu Mar 22, 2012 3:50 am

I love it.

Mmm...but is time all encompassing? Can you be 'outside of time' as an observer? Which would suggest a different threshold of reality/experience.
“Integrity has no need of rules.”

-Albert Camus

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Pigeon
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Re: Bootstrap paradox

Post by Pigeon » Thu Mar 22, 2012 3:54 am

Doubt one can separate. Does time flow at the same rate for all living things? Doubt it.

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Royal
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Re: Bootstrap paradox

Post by Royal » Thu Mar 22, 2012 4:08 am

Talked to a dude reading a book "Dancing with Water". In this book shows the latest research regarding the magical properties of water.

He mentioned that there was vortexes in a river flowing the opposite way. It's these vortexes that allow fish to swim easily against the current.

If time operated more as a river rather than rama's arrow, than I can see time travel being possible.

There is also quantum experiments that prove light travels backwards. Using that idea, one can extrapolate the content of our experience in modalities where time sometimes doesn't exist (Dreams, meditation...). And maybe the more emotionally charged (like the intensity of a stone in a pond creating ripples) the more of that light we can see in dreams and mediums.

Apply this to the sun, solar flares, a river of particles and it get's pretty interesting.

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Pigeon
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Re: Bootstrap paradox

Post by Pigeon » Thu Mar 22, 2012 4:20 am

Did you look at the strange loop post - neurons vs awareness

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Royal
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Re: Bootstrap paradox

Post by Royal » Thu Mar 22, 2012 4:49 am

I skimmed. But I will take a closer look now that you mentioned it.

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