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A machine that predicts the future

  1. Sep 28, 2005 #1
    ok a friend and I came up with this hypothetical situation, and we both believe totally different things about it and Im positive Im right, but I suck at explaining stuff so if anyone can tell me if Im wrong or if Im right, can explain it better than I can?

    ok here are the two assumptions:
    1) we have no free will: everything, including humans, is made up of atoms that react to forces. our belief in free will is just an illusion made from the complexity of our "atoms"

    2) there is a machine that can predict the future by calculating all the forces on every atom in the universe.

    ok, so now what would happen if you saw your own future? What I believe is that the machine would have to show you a future where seeing that future is part of the future. It could only show you a future, that after seeing, you would cause to happen. If the machine showed you getting into a car, which then blew up, you would get in the car. However (this is where we had different opinions), you would feel like you were making a decision to get into the car still. The illusion of free will would still be there (even though you would now know there no such thing, it would still feel real), and you would have some reason for getting into the car. Maybe your suicidal, or maybe you had some other reason idk. But the point is, the machine could only show you getting into the car, if after seeing your own death, you still want to get in the car.

    my friend on the other hand, believes that after seeing your own future, the illusion of free will would be lifted. You would feel like a robot being forced to do everything the machine predicted. You would be forced to get into the car, even if you didnt want to die.
  2. jcsd
  3. Sep 28, 2005 #2
    This machine cannot exist : since it needs to know everything in the world, it knows everything about its own atoms. And where is this information stored ?

  4. Sep 28, 2005 #3
    haha well the machine is an assumption, just pretend it exists. But a computer can store its own atoms in it. just picture the moon, covered in hard drives lol.
  5. Sep 28, 2005 #4
    actually Im not sure if a computer can store its own atomic information, cause the more it needs to store, the bigger it gets, making it need to store more.. But umm yea pretend this is far into the future and we have super efficient, fast, computers with a lot storage.
  6. Sep 28, 2005 #5
    Ok, our supercomputer can store all the world information in its superHD. However, it has to store its own superHD in the superHD too. HOW??? :-))

    In other words, the information relative to each atom in te world would need at least one more atom inside our supercomputer. But our computer is part of the world, so...our computer can not exist :-((

  7. Sep 28, 2005 #6
    I think your wrong, Im not rly up to date on this but Im think a quantum computer uses each atom for a lot more than 1 piece of data (not that they exist yet). But whether this machine is possible or not, just pretend it is, and its been created, cause you could imagine what one would do.
  8. Sep 28, 2005 #7
    Each piece of data in the world needs to be stored in (at least) 1 piece of data inside our computer...
    It doesnt matter the name the smallest particle has; each particle needs to be described in some way inside our computer, including itself! And this is the problem.

    The same way you got a kind of recursion when you said "that the machine would have to show you a future where seeing that future is part of the future", I'm saying the existence of this computer, itself, is a kind of recursion, too.

    Maybe, such computer could "evaluate" the future. And this would mean "free will" is just an illusion. Or maybe, one could say this computer - that can see our future - could never be in our world, and its name is God...:-)

  9. Sep 28, 2005 #8
    ok yea ur right, the machines impossible to build, but just act like it was possible, like you could go on your computer, and find out your future.
  10. Sep 28, 2005 #9
    Maybe one day Physicist will find a Spread spectrum of Quantum entanglements that will give a super computer the ability to see the past and future events and possibly some other amazing things. :smile:
  11. Sep 28, 2005 #10


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    How bout this

    You see yourself getting into the car
    you shoot yourself in the head right after seeing your future
    What happens lol.

    Or you could see yourself shooting yourself in the head right after you see the future
    But you decide not to
    Then what happens.
  12. Sep 28, 2005 #11
    If that was the case then it would become a propability and not a certainty, If you seen it more than once then it will probably happen even if you tried to prevent it, May be from something overwhelming with emotions that you weren't presently aware of.

    But if it was a probability then it could be changed if recognized as the event begins to occure and you were aware of it, but if the image changes the next time then you may have prevented it, It would require a double check on the probability.
  13. Sep 28, 2005 #12


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    But then there would be no such thing as the future, just predictions.
  14. Sep 28, 2005 #13
    ok, the assumptions were that everything is predictable, it that everything follows the laws of physics, and we are just reacting to the forces on out atoms. The other one was that this machine exists. Im not argueing either of these points, Im just trying to figure out would happen if you viewed the machine.

    the machine would never show you getting into the car if after seeing that you shoot urself in the head. The machine includes you viewing your future in its prediction, so it rly HAS to give a future, that after seeing it, you wont **** it up. It can predict your reactions to the future you see.
  15. Sep 29, 2005 #14
    It would be a prediction for the observer only, anyone else who has no clue would be subject to the probability of any prediction, For the observer, The Observer would have to check twice to see His/Her new possible outcome.

    If it doesn't sway then it would happen. :smile:
  16. Sep 29, 2005 #15

    Ivan Seeking

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    Just to be clear, no machine could predict the future even if it had all existing data at hand. The clockwork universe died with Quantum Mechanics. For example, we cannot predict when a particle will decay. Nor can we predict the path of any subatomic particle. And beyond that, Heisenberg's principle makes it impossible to have exact knowledge of both position and momentum, or energy states and transition times. So, the current physics makes the universe inherently unpredictable.
  17. Sep 30, 2005 #16
    Time loops have been seriously studied by physicists, and under certain (extreme and stringent) circumstances, they are not forbidden by the laws of physics.
    But there are some must requirements if you want a time loop to happen.

    A first option is that both past (you seeing the future) and the future (whatever is seen from the past) must be consistent. This means whatever happens in the past can not change the future and viceversa. In this case, it seems practically impossible that you could ever see yourself dying and then do anything to prevent that from happening. You would die in that way no matter how hard you try to avoid it. But that wouldn't necessarily mean that freewill is cancelled, only that even with freewill there are things which are beyond your power to change the future.

    Another possibility is that you could only see things about the future that you have no possibility to affect in any way. In this case you would probably never be able to see yourself (although there is a wonderful sci-fi story by Stanislaw Lem in his book Star Diaries where the main character Ijon Tychi's spaceship continuosly enters in time wirlpools and he sees several versions of himself, anyway keeping the whole story fully consistent, just this chapter is worth the book).

    Another possibility is the "multiverse" or "many worlds" theory, in which several (many, maybe infinite) parallel universes exist, in some of them you die and in some you don't. Therefore if you "change your future" you are in fact switching from one universe to another.

    In any case as mentioned by others, such a machine is (as far as we can tell) impossible even in principle. If it could show the future it would not be because it knows all the exact conditions of the present. The laws of quantum physics forbid such a complete knowledge, and even knowing all what is knowable, the future is probably still unpredictable due to the probabilistic nature of the laws.
    Last edited by a moderator: Oct 1, 2005
  18. Oct 1, 2005 #17
    I have often wondered if the past and future were changing independently of time, so that if you could go back to the past, it might not be the same as it was when you were there last. I suppose this could happen if there were more than one time-like dimension.
  19. Oct 8, 2005 #18
    I agree with the idea "it is impossible even in principle to predict the future with 100% accuracy because of quantum effects". But we do not need to resort to quantum effects to show that such a prediction is non-sensical. If we allow perfect prediction in principle (as a thought experiment) this perfect computer still would not be able to "show" a person's future to that same person.

    Let's call the computer "42" and the person "Douglas". 42 calculates what Douglas's future would be knowing that Douglas has not yet seen the future..... but on showing the future to Douglas, the starting assumptions have changed (Douglas now knows the future, where he did not know it before), therefore the future calculated by 42 is incorrect.... so 42 makes another calculation based on Douglas having seen 42's first prediction of the future, and shows this new prediction to Douglas..... but now the starting assumption has changed again (Douglas has seen a different future, 42's second attempt at prediction, compared to the future 42 had assumed he had seen to start with)..... I hope you can see that this is a never-ending self-referential loop, hence logically will not terminate.... ie there is no solution.

    And it says absolutely nothing about the existence or non-existence of free will (whatever that might be).

  20. Oct 8, 2005 #19
    ok wtf, this is the philosophy section. I know that some things are actually random, but Im assuming nothing is random, and everything is predictable. And btw, a computer could technically hold all the data in the universe. Compressing the data would allow it to store its own atomic data and still have room for more. But this has nothing to do with my question. Im just trying to figure out, what would happen to you after you see the future in a world where everything is predictable.
  21. Oct 8, 2005 #20
    o yea and Im not claiming to know anything about quantum mechanics, but its possible that everything is still predictable. Just because things seem random to us doesnt mean they are. Maybe there are particles and forces smaller than quarks that govern the way everything acts, and because they are too complex and small, we cant predict them, and therefore say that particles act randomly.
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