1. Welcome to Religious Forums, a friendly forum to discuss all religions in a friendly surrounding.

    Your voice is missing! You will need to register to get access to the following site features:
    • Reply to discussions and create your own threads.
    • Our modern chat room. No add-ons or extensions required, just login and start chatting!
    • Access to private conversations with other members.

    We hope to see you as a part of our community soon!

Featured Is the PAST determined?

Discussion in 'Science and Religion' started by Polymath257, Aug 13, 2019.

  1. suncowiam

    suncowiam Well-Known Member

    Joined:
    Sep 25, 2014
    Messages:
    5,601
    Ratings:
    +2,223
    If I had a video of the event with a timestamp, would that count?

    Law enforcement would say yes, but I know you're a physicist so * Shrug *.
     
  2. Milton Platt

    Milton Platt Well-Known Member
    Premium Member

    Joined:
    Aug 27, 2015
    Messages:
    6,494
    Ratings:
    +2,455
    Religion:
    Atheist
    In theory, if we have enough information, we could extrapolate back to a past event.....we do it all the time. Since we know the distance and speed a planet travels around the sun, we could extrapolate it's position at any time in the past. We can and have extrapolated past solar and lunar eclipses.
    In your examples, you are simply acknowledging a lack of information to do the extrapolation. There are simply too many variables along the way. Our lack of knowledge or ability to pinpoint virtually all past events does not prevent extrapolation of some events.
     
  3. robocop (actually)

    robocop (actually) Well-Known Member
    Premium Member

    Joined:
    Oct 24, 2013
    Messages:
    2,713
    Ratings:
    +478
    Religion:
    newly baptized into Church of Jesus Christ of Latter-day Saints
    For me, the past exists only as a type of thought; hence it is not determined; it's not even existent.

    But I picked up a Physics book to challenge my thinking.
     
  4. Hockeycowboy

    Hockeycowboy Well-Known Member
    Premium Member

    Joined:
    Oct 28, 2015
    Messages:
    5,501
    Ratings:
    +3,160
    Religion:
    Christian
    Yep, I believe so. I certainly hope so!

    If time travel to the past ever becomes possible, people’s very existence could be negated!
     
  5. Hockeycowboy

    Hockeycowboy Well-Known Member
    Premium Member

    Joined:
    Oct 28, 2015
    Messages:
    5,501
    Ratings:
    +3,160
    Religion:
    Christian
    Anyone ever see “Final Countdown”, w/ Kirk Douglas and Martin Sheen?

    They couldn’t, so that settles it! Lol.

    It was a good movie.
     
  6. shmogie

    shmogie Well-Known Member
    Premium Member

    Joined:
    Nov 8, 2014
    Messages:
    7,100
    Ratings:
    +1,387
    Religion:
    Christian
    Just quoting Hawking and his view on time travel.
     
  7. Polymath257

    Polymath257 Think & Care
    Staff Member Premium Member

    Joined:
    Mar 28, 2017
    Messages:
    12,028
    Ratings:
    +11,662
    Religion:
    Non-theist
    Ahh...but how do you know all that information is preserved? In fact, don't we expect the information to gradually degrade, meaning more than one past becomes possible?

    And I agree, there are a LOT of past events that *are* determined by the present. Anything from which the information hasn't decayed too much will be determined. But it seems quite unlikely that *all* past events are of that sort.
     
  8. Brickjectivity

    Brickjectivity Veteran Member
    Staff Member Premium Member

    Joined:
    Dec 8, 2012
    Messages:
    25,547
    Ratings:
    +8,027
    Religion:
    Liberal Christian
    It also appears that as you go forward in time there are fewer possible pasts which can explain it. Example: there are only so many ways that our solar system could be arranged in a way that would allow life to thrive on Earth, so that excludes numerous possible pasts.
     
  9. Polymath257

    Polymath257 Think & Care
    Staff Member Premium Member

    Joined:
    Mar 28, 2017
    Messages:
    12,028
    Ratings:
    +11,662
    Religion:
    Non-theist

    But I'm not even going as far as to allow travel into the past. I am simply saying that certain events in the past are underdetermined and so have no actual truth. Other events certainly *are* determined, at least to some extent.

    We always assume there is a 'truth' about the past that is well-determined in some way. But what is that assumption is wrong? That for some events in the past, it is actually the case that they could have been either of a couple (or a few) different ways and still lead to the present that we see today?
     
  10. Polymath257

    Polymath257 Think & Care
    Staff Member Premium Member

    Joined:
    Mar 28, 2017
    Messages:
    12,028
    Ratings:
    +11,662
    Religion:
    Non-theist
    I'm not of that. Again, if the information decays, then the number of events in the past consistent with the present would *increase* over time. As an example, I'm sure that quite a few different pasts for 68 million years ago would be consistent with the present. The information determining the past has been degraded to such an extent that saying there is only one past seems to be less clear.

    Part of this, of course, is figuring out in what sense 'the past' exists. And, for that matter, to what extent something existed if there is no information that has survived showing its existence.
     
  11. shunyadragon

    shunyadragon Veteran Member
    Premium Member

    Joined:
    Mar 23, 2017
    Messages:
    11,698
    Ratings:
    +5,218
    Religion:
    Baha'i Faith
    I believe considering it a 'truth' issue goes too far.
     
  12. Polymath257

    Polymath257 Think & Care
    Staff Member Premium Member

    Joined:
    Mar 28, 2017
    Messages:
    12,028
    Ratings:
    +11,662
    Religion:
    Non-theist
    Hmmm....I'm not sure where you get this from, but as stated it seems to be wrong. We are limited to travel in our future light cone. We would only be able to interact with that galaxy in *its* future light cone. So I see no sense in which we can go into the past of even a distant galaxy and change it.

    Again, this is certainly not part of any standard cosmological dynamic. Do you have a reference for this?
     
  13. cladking

    cladking Well-Known Member

    Joined:
    Mar 4, 2018
    Messages:
    1,114
    Ratings:
    +152
    Religion:
    not applicable
    Nothing is determined or determinable.

    But still only one single past existed and only one single future will exist. In the future we will be able to determine things about the past that we can't at this time just as we'll get better and better at predicting the future. The difference is that the past is set and immutable but the future is subservient to free will.

    The present is also an enigma but we don't really notice this because we live in our models and see what we expect.
     
  14. Brickjectivity

    Brickjectivity Veteran Member
    Staff Member Premium Member

    Joined:
    Dec 8, 2012
    Messages:
    25,547
    Ratings:
    +8,027
    Religion:
    Liberal Christian
    What counts as or is an example of degrading of the information?
     
  15. Polymath257

    Polymath257 Think & Care
    Staff Member Premium Member

    Joined:
    Mar 28, 2017
    Messages:
    12,028
    Ratings:
    +11,662
    Religion:
    Non-theist
    Well, for example, for Casar's last drink, the size of the cup, the amount of water in the pitcher, etc, would be information on how much he consumed. But the cup is probably long gone and any association with him irreproducible. The pitcher is also long gone and was probably reused so retained very little information about Ceasar's last drink, even before it was destroyed.

    Or, we can mention someone's last words that were not recorded. The vibrations in the air went to equilibrium pretty quickly and and anyone with memories would have died, so if there isn't another source of information about those last words, they are simply not determined by the state of the universe now.

    Or suppose that there were two people there when those last words were spoken, but one remembers one thing and the other a different thing. Is there any real sense in which one or the other is 'correct'?

    Typically, all increases of entropy are equivalent to a decrease of information.
     
  16. Road Less Traveled

    Road Less Traveled Active Member

    Joined:
    Jun 27, 2019
    Messages:
    482
    Ratings:
    +109
    Perhaps it is dependent on if all information is preserved, stored, carrying on in a form of energy/light that can’t be destroyed. And then if that information can separate and branch out. Like the complete set of information regarding something/a particular event being an entire puzzle, and if it can branch out into many many pieces.
    Then if that information can be re-written over, slightly altered, etc. Routinely traveling through past, present, future in its whole/pure form or dispersed into many pieces.

    I haven’t kept up on information models and what’s been tested, and/or theoretical in awhile. And as always, I’m sure that there is so much still unknown regarding information, what degrades if anything, how it’s preserved, where it’s preserved, what exactly is preserved, where it goes, how and if it can disperse into pieces through ‘time,’ how’s it subjected by ‘time’ if at all.
     
  17. Brickjectivity

    Brickjectivity Veteran Member
    Staff Member Premium Member

    Joined:
    Dec 8, 2012
    Messages:
    25,547
    Ratings:
    +8,027
    Religion:
    Liberal Christian
    It is from an explanation that treats spacetime like a loaf of bread.
    youtube go to minute 4:25 Its based on something called the block time universe. Its attributed to Brian Greene, although I don't know where and if he publishes that. He does a talk about string theory (which I have not seen) on Ted talks.

    Entropy is a thermodynamic relation in which order tends towards chaos and heat tends to dissipate into coldness. In some cases it can be quantified, but generally its used only as a relation. It is believed by most Astronomers that the universe is getting colder and that it will eventually reach maximum entropy at which time all light will be gone, and the temperature will be very low or possibly zero Kelvins. Thus most Astronomers believe there is an end to change in this universe, and if that is so then there is a lowest energy state at that end.

    I don't have a reference for my comment, but I want to clarify . I wasn't considering the possibility of information degradation only the possibility of time travel causing changes in the past. If time travel was the only way of changing the past then the end of the universe would imply that all time travel eventually ended, that spacetime ceased changing; but that would contradict time travel. It would not be consistent with the ability to time travel, even with such far fetched means as traveling in that cone. A final, uniform, low entropy universe seems inconsistent with time travel.
     
  18. Brickjectivity

    Brickjectivity Veteran Member
    Staff Member Premium Member

    Joined:
    Dec 8, 2012
    Messages:
    25,547
    Ratings:
    +8,027
    Religion:
    Liberal Christian
    Or so you represent to me. They certainly are not visible to us today, but I'm not sure how you insist the information is gone when it may merely be unreachable.

    So this seems to beg the question, since its a thread about whether the past is preserved. I don't think it has to be preserved in movie format or on a stored drive to exist in the past apart from us. We can assume that the past disappears or not. What is the evidence that it is gone? Well we do have the fact that nobody remembers how much Caesar's cup holds; so we can't compare. That's an uncertainty.
     
  19. Brickjectivity

    Brickjectivity Veteran Member
    Staff Member Premium Member

    Joined:
    Dec 8, 2012
    Messages:
    25,547
    Ratings:
    +8,027
    Religion:
    Liberal Christian
    Oh..yes I am wrong about that. We can't.
     
  20. Skwim

    Skwim Veteran Member

    Joined:
    Jun 20, 2010
    Messages:
    26,316
    Ratings:
    +10,444
    Religion:
    Agnostic
    Yes.

    Yes.

    Of course not because an event can be caused in more than one way, and without access to the past there's no way of determining which of the "more than one way" was responsible for the event.

    .
     
    #60 Skwim, Aug 13, 2019
    Last edited: Aug 13, 2019
    • Winner Winner x 1
Loading...