As a layperson, time travel seems impossible to me. Prove me wrong!

Discussion in 'Science' started by Patricio Da Silva, Dec 25, 2021.

  1. WillReadmore

    WillReadmore Well-Known Member

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    I'm not so sure. I think any interaction of any kind would change history in ways for which there is no accounting. It would be a new event inserted in a history that did not include that event.

    It's easy to talk about the death paradox.

    But, a conversation or even just a sighting could change history.

    Maybe that Bosnian would miss his shot at Archduke Franz Ferdinand if distracted by a ghost from the future. Thus, avoiding how WWI got started.
     
  2. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    What did I make up in the field of physics? I looked over my writings, and I found nothing.
    Where do you get this idea?
    Where do you get these ideas? I'm curious.
    So, we are off onto pernicious social problems hating experts? With respect to anything specific that I wrote, where can you
    possibly get this idea?

    Did I not refer to experts?
    Did I not refer to a few PHDs?

    Where, do you get these ideas from anything I have written that I hate experts, Einstein? Explain this to me, please.
    That is as I suspected,
     
    Last edited: Jan 15, 2022
  3. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    I wasn't offering the wiki quote as evidence for anything, I just assumed it was what science is saying. As to what the wiki quote meant, I do not know.
     
  4. WillReadmore

    WillReadmore Well-Known Member

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    In the OP you said you are guessing and indicated interest in what the real situation is.

    But, now you're asking the same question again.
    My previous answer was that you stated:

    "Therefore, time, in reality, does not exist,"

    Einstein showed us that time is a part of space-time, the universe we live in. You can't remove time any more than you can remove any of the spacial dimensions.
     
  5. WillReadmore

    WillReadmore Well-Known Member

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    Well, one has to notice that the quote states that it includes untested ideas that presume faster than light speed travel.

    The standard model of physics includes a very serious speed limit. It gets called light speed, because light travels at that speed in a vacuum. Gravitational waves also travel at that speed. (They can both travel that fast, because they have no mass.) The standard model does not allow for any possibility of accelerating an object that has mass up to that speed regardless of how much energy gets applied.

    You can think of it as taking more energy than represented by the entire universe, applied to accelerating an atom - a serious speed limit.
     
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  6. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    You really need to stop telling me I disrespect physicists and Einstein, that's nonsense. Stop it.

    If I say something that conflicts with Einstein, of course I will defer to the more knowledgeable.

    I've stated that I'm a lay person, many times. How much humility is required before you stop accusing me of disrespecting scientists? tell me so I can dish out a heap more so you'll stop it.

    I'd love nothing more than to converse in the universe of physics, I wish I could, but at 70, it's a little late in the game for me to do much about my lack of physics knowledge, other than to fix plumbing, etc.

    You have a fundamental misunderstanding of my point.

    Now then, we have the past, the present, and the future.

    Right?

    Does not our perception of 'time' pretty much involve our embodiment of these three, the past, the present, and the future?

    Is this not true?


    The past used to exist.

    Is this not true?

    The current, the here and now, exists (though it's continuing).

    Is this not true?

    The future which has yet to come, will exist.

    Is this not true?

    Now, of the three, the only one that actually does exist, is now.

    True for false?

    Oh, it exist in memory, record, can always be referenced by man and machine, and the future in imagination, can be predicted in some ways that are useful, sure.

    Not talking about that. I'm talking about here and now, what actually exists here and now.

    Well, here and now. The only thing that exists here and now is the here and now

    AM I right or wrong?

    This, you must understand, this doesn't deny the existence of time. Don't take me out of context, please.

    ANd by that fact, doesn't disrespect Einstein.

    To say that the past used to exist, but we can reference records of it, and the future will exist, and we can try to predict it, doesn't conflict with science.

    If I say the past exist in the abstract, and the future exists in the abstract, that its because the only thing that does exist in the here and now is the here and now, so where does that leave the past and the future?

    There is only one place left, and it's the abstract.

    But that's not physics, it's psychology. Since it IS psychology, it cannot conflict with Einstein.

    Let me ask you a question.

    Can you see the difference between a label, and the object to which the label is attached?

    For example, can you see the difference between the label 'dog', and the animal which the label is most often attached to?

    yes or no, will do.

    If you cannot, then that will explain why you misunderstand me. And knowing that, will provide me with some relief as to why you behave the way you do.
     
    Last edited: Jan 15, 2022
  7. WillReadmore

    WillReadmore Well-Known Member

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    If what you are desiring to discuss is psychology, then I'm out.

    I didn't get that from your OP. To me, you sounded like you were referring to physics.

    So sorry!
     
  8. kazenatsu

    kazenatsu Well-Known Member Past Donor

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    None of us can tell you for certain. It's possible the past still exists.
    It's also possible the past exists but is constantly changing, and may not still be what we remember it to be.
     
  9. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    Given what we, you, and I, know, for certain, this very moment, does the past still exist?

    For me, it ONLY exists as a record, either in print, or the mind, but both exist in the abstract.
     
  10. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    Can I ask you a very simple question?

    Can you see that the meaning behind words in print, or in speech or sound, exists as a function of mental processes?

    Can you see that or not? Yes or no.

    ( I have a reason for asking it which IS relevant to the OP).
     
    Last edited: Jan 16, 2022
  11. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    And I've stated many times that Time, like all metrics, exists in the abstract.

    What that means is that the meaning behind words, letters, and numbers and symbols, in print, are a function of a mental process.

    That fact is self-evident and of no consequence to mathematics functionality. That is why what I'm expressing it doesn't conflict.

    You can't remove the abstract from any mathematical equation (which is to say the meaning behind words, symbols, letters and numbers in print, and given it's self - evident and of no consequence, there is no need to indicate the fact), yes, and the point is, my point doesn't conflict with Einstein.

    Einstein doesn't harp on this fact because it's self - evident and is of no consequence to the equations, themselves.

    I"ve qualified that statement many times, and here you are taking it out of context.
     
    Last edited: Jan 16, 2022
  12. WillReadmore

    WillReadmore Well-Known Member

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    I assumed this had to do with science when you started talking about time not being real, time travel, etc.

    I think you're presenting nominalist views (as opposed to Paltonism or Quine). But, I don't believe the questions of philosophy on that point have anything to do with our sciences.

    Whether someone says time is real or not real, whether someone says numbers are real or not real, etc., etc., it doesn't change anything we have discovered through our scientific exploration.

    Physics still can't even be described without the use of math, for example. For a Platonist, and skipping a step or two, that makes numbers real. For a nominalist, I would guess that pretty much NOTHING about physics is real. For example, I think many nominalists would deny that there is reason to be certain that our model of physics will be true tomorrow, regardless of whether it is true today - after all, there isn't proof that even fundamental laws of physics will be true tomorrow. It just happens to be our experience so far.

    Nominalists differentiate between velocity and acceleration!! They can see velocity as not real, but acceleration as real!

    Whichever way one chooses to go with the various conclusions of philosophy on these points, physicists point out that e=mc^2 means the same thing and is just as true regardless of what anyone might think is a number or time.

    Which is, I think, the same as suggesting that this issue doesn't belong in the science section.

    Remember I was asking what your comments actually mean on physics. So far, I think the answer is that this is not an issue that physicists find a use for.
     
  13. Space_Time

    Space_Time Well-Known Member

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    Are you vibrating:
     
  14. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    You started this thread in December and have traveled to the future since. So you CAN travel through time. QED

    PS, You can make a functional time machine using a black hole. But as with all real time machine concepts, you can only go back in time to the moment you entered orbit [or turned it on]. And if I could do the proof there is zero chance you would understand it anyway. :)
     
    Last edited: Feb 26, 2022
  15. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Here, from the Journal Nature ["Closed timelike curves" is physics-speak for time travel.]

    Experimental simulation of closed timelike curves

    Abstract

    Closed timelike curves are among the most controversial features of modern physics. As legitimate solutions to Einstein’s field equations, they allow for time travel, which instinctively seems paradoxical. However, in the quantum regime these paradoxes can be resolved, leaving closed timelike curves consistent with relativity. The study of these systems therefore provides valuable insight into nonlinearities and the emergence of causal structures in quantum mechanics—essential for any formulation of a quantum theory of gravity. Here we experimentally simulate the nonlinear behaviour of a qubit interacting unitarily with an older version of itself, addressing some of the fascinating effects that arise in systems traversing a closed timelike curve. These include perfect discrimination of non-orthogonal states and, most intriguingly, the ability to distinguish nominally equivalent ways of preparing pure quantum states. Finally, we examine the dependence of these effects on the initial qubit state, the form of the unitary interaction and the influence of decoherence.
    https://www.nature.com/articles/ncomms5145
     
    Last edited: Feb 26, 2022
  16. WillReadmore

    WillReadmore Well-Known Member

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    Do you agree that this is limited to theoretical physics, where this concept and others can not be tested and have not been observed?

    I certainly don't mean to be critical of this incredibly interesting idea in any way. And, theoretical physics has a hugely important role in determining where experimentalists should be looking.

    But I do like knowing where such ideas reside - whether they are experimental science, theoretical physics, religion, etc.
     
  17. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    Yes and no. We could make a time machine using a black hole tomorrow if we had a black hole handy. That is possible because of frame dragging, which we observe here on earth. We have to compensate for this in our satellites. So while the gravity field of a black hole is far stronger that here on earth, the math is the same. Also, these are solutions that originate in Einstein's General Theory of Relativity, which is well tested and over 100 years old now. So this isn't like concepts in String Theory that can't be tested and do not originate in a well tested theory. These are merely mathematical solutions to a well-established core theory of physics.

    In short, time travel to the past is possible. We just don't know if it could ever be done in a practical sense. And it doesn't work like a time machine in a movie. As I said, one common limitation to all known designs is that a time machine can only take you back to the moment the machine was turned on [or the moment you entered orbit around a black hole].
     
    Last edited: Feb 27, 2022
  18. HereWeGoAgain

    HereWeGoAgain Well-Known Member

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    But you can travel as far into the future as you like. You just have to go fast enough.

    This too we know is true but is difficult to demonstrate beyond nanosecond changes. It has been measured but it is beyond our ability to make a ship that can travel at 0.9999... C. [99.99% the speed of light or more]

    However, if you take two atomic clocks that are perfectly synchronized, leave one at the base of a mountain and take the other one to the top, the one on top runs faster than the clock at the base of the mountain.. This is true because clocks run slowly in gravity fields. And the gravity at the top of a mountain is slightly less that at the bottom.
     
    Last edited: Feb 27, 2022
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  19. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    That hasn't actually what has occurred. What has occurred is that the 'now' has changed, as it always does.
    now is not the future, it is still now.
    Above my intellectual paygrade. I thought black holes will kill you.
     
  20. kazenatsu

    kazenatsu Well-Known Member Past Donor

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    And you agree that you can affect that change, correct?

    So the only question is whether you can (now) only affect the future or whether you can also exert an effect on the past. If you can exert an effect on the past, then that goes a long ways towards proving (within the framework of the argument you have constructed) that time travel is theoretically possible. (Because if you can affect the past, then it would allow you to put (or have put, depending on the words you want to use) a future version of yourself there.

    Even if we agree with your argument that only the current moment exists and it is constantly changing, it would still be possible for your future self to have existed and been conscious in a distant past moment in time. It is only that you have to do something now in order to make sure that that happened.

    I am not sure why that should be less meaningful to you than the normal action of acting in the present to exert an effect on the future.
     
    Last edited: Feb 27, 2022
  21. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    All that exists is now. so, now is the only thing that can be affected.

    Whatever you do, wherever you go, it won't be yesterday or tomorrow, it will be you changing now. Now is all that exists.

    Yesteday, Tommorrow, they exist ONLY in the 'abstract', you cannot actually travel to them as neither exists in the physical realm.

    However, if someone with quantum whatever proves me wrong, I am all ears and eyes.
     
    Last edited: Feb 27, 2022
  22. kazenatsu

    kazenatsu Well-Known Member Past Donor

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    You started this thread. Why did you do that? You obviously had an intention of exerting an effect on the future.
     
  23. kazenatsu

    kazenatsu Well-Known Member Past Donor

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    But time travel could still seem to exist, even if what you said were true.

    You see that, don't you?

    An object that seems to be going back in time would not actually be going back in time, the same way that an object that seems to be going forward in time would not actually be going forward in time. The presence of a state of being in the present has an effect on the future state of being. We both agree with that.

    The only difference is you seem to believe the flow of causation has to follow the current flow of time.

    Why can't someone affect something that happened, even if it no longer exists, and then by affecting what happened in the past, thereby affect what will happen in the future?
    Why is it unreasonable that the presence of a state of being in the present could have an effect on the past state of being? Even if that past state of being no longer exists, it will eventually have an effect on whatever state of being currently exists.
    Basically a giant U-turn of causation. Suppose on the second day, I press a button that will affect what happened on the first day, and then what happened on the first day will make something else happen on the third day.
     
    Last edited: Feb 27, 2022
  24. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    I can only exert an effect of or on 'now'. The future does not exist.
     
  25. Patricio Da Silva

    Patricio Da Silva Well-Known Member Donor

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    As you act in the now, you will affect the now.

    The future never comes. The only thing that is affected is now.


    To say ' I will affect a point in time in the future' is misleading.

    When that point actually becomes affected, it is now.

    Now is the only thing that changes.
     

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