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Changing Past and Future

  1. Dec 1, 2003 #1
    I do not pretend to be a genious mathematician,
    but the theories discussed here intrigue me.

    I would imagine that majority of people who come to
    this forum are very familiar with Dr. Kaku's work, and
    similar work of other scientists.

    My question is, can past or future be altered?

    You see, in my opinion, neither one can be altered. The
    future has already happened. And no matter what we do
    to prove that we guide our own live (which we do), the
    future has already been decided, not necessarily for us,
    but by us.

    If we consider time to be just another dimension complementing
    the other three, than consider the following example.

    When you are riding in a train, the scenery in your view changes since you
    are moving along the axis. If you can't see the building that is one mile
    away from you, it doesn't mean it does not exist.

    Our travel in time that we partake in every second, is similar to
    the above travel in a train. The view in front of us changes
    constantly over time since we are moving along the time axis.
    But the fact that we cannot see what will happen one year from now,
    does not mean it does not already exist.

    Thus, if time is just another dimension, it should be possible for us
    to travel back and forth through time. But whatever is going to
    happen, has already happened and we are powerless to alter the events.
  2. jcsd
  3. Dec 1, 2003 #2


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    If you look at Dr. Kaku's interview, you will see that he favors the multiple worlds interpretation of quantum mechanics, where worlds branch off each other at every quantum "measurement" or decision point. So if then you go back in time and alter something, the alteration goes off on a new, different branch than the one you came down, and the original one is still unchanged. This works; it is self-consistent, but it requires you to believe in skillions of parallel worlds (actually in the only meaningful sense, perpendicular ones).
  4. Dec 3, 2003 #3


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    I'm still trying to get aquatinted with this forum and can't find any links to Dr. Kaku's interviews. I find this multiple worlds thing interesting. Can you help me out here?

  5. Dec 4, 2003 #4


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    I have moved that thread down to "Publications" in "The works of Dr. Kaku". It's called "Borrowed Time, an Interview with Michi Kaku".
  6. Dec 4, 2003 #5


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    Thank you sir. Interesting read.
  7. Dec 4, 2003 #6
    Now, correct me if I am wrong, but according to quantum theory, an electron takes multiple paths at once when not being observed. I get this from Schrodingers clever cat experiment. When observed, these electrons are forced to take a certain path. This would explain photon interference, such as the double slit experiment. (wave-particle duality) if you are more familiar.

    If this is correct, this would imply that the future can be altered. For it depends on which path these subatomic particles care to take.

    Make of this what you will, but that is my guess.
    Paden Roder
  8. Dec 4, 2003 #7


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    You are describing the path integral or sum over histories method. If you want to calculate the amplitude ("square root of probability") for a particle to go from point A to point B, you compute the amplitudes for all possible paths and add them up. Since these amplitudes are complex numbers, they have direction, and the ones for paths going this way will cancel the ones for paths going that way, leaving only the ones for the "classical path". That's the idea, and the mathematical calculation is done by the integrals over paths that Fetnmann thought up.
  9. Dec 4, 2003 #8
    You spoke a lot about amplitude. And it gave me a peak of imaginability. Could this amplitude (which is often directly related to Geometry) be a 'key-role' into a incenter or centroid multi-dimensional universe? I know scientists came up with the theory of the universe being dodecahedral, but would amplitude correlate with centroids? I'm not sure, so I'm just looking for some insight, selfAdjoint.

  10. Dec 5, 2003 #9
    Too be all honest with you Jeebus, that was the impression I was under. Any info. would be great, SelfAdjoint.
    Paden Roder
  11. Dec 5, 2003 #10


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    I don't know if amplitude per se leads directly to dodecahedra or the anything else in cosmology. Amplitude is a complex number, the mathematical correlative of a "wave function". The value of a wave function is an amplitude, that complex number. And if you multiply that complex number by its complex conjugate, you get a real number. And after normalization that real number can be interpreted as a probability. All of this happens in the context of ordinary quantum mechanics, about subatomic particles.

    Now cosmologists have said various things about the wave function of the universe, aka the amplitude of the universe. You are certainly free to cheer them on.
  12. Dec 5, 2003 #11
    I think that you are right, ambient. As you can see under the thread “Bananas” I discussed the logical/physical possibilities of altering events in space/time and how we suppose to take this issue by the numbers. I must say that we should remember that our intuitions are not very used to notions of time travel, quantum/relativistic physics and the sort, and that paradoxes like the ‘grandfather paradox’, are nothing but common sense.

    I’m also bound for the conclusion that the point is not – anything that can happen, will happen; but - everything that can happen has already happened. We cannot change history but only contribute to it. But this raises some questions about free will, right? Consider a rock for example: if you see a rock on the ground, you have many options of what to do with it, yet you can only take one option at a time..... yes I know, you want to go back and change that option. But what were the factors that made you take that option in the first place, why you didn't take any of the other options? Asking so, we'd have to take in consideration a lot of things, you see? Things that at this moment we can't figure out, for instance: We don’t know what will be encountered behind the doors that time travel may possibly open, such as higher dimensions and higher states of conscience (hyper numbers). At this point (or at any other point), we cannot “stack the deck”. Even when you get up to go to work you have on your mind a plan for the day but we all know that it won't happen exactly as predicted, right? If we were able to travel to the future then we’d certainly know what happens in the future, so knowing our future position, we would make everything to contradict or not that position, however, that’s exactly what makes us take that position in the first place, what a loop hun? It goes to a point that seems to surpass our capability of abstraction.....

    About parallel universes, let me tell you that the current theory considers the idea as ‘unsound’ (as we all know), mainly because the present interpretation of relativity permits only a single observer (and a single observation) at a time. So if you judge as 'unsound' a thing as the fact that more than one person can observe an apple at the same time, the present theory fails. However, the recognition of such a simple proposition as multiple simultaneous observations leads to physics so strange and hard to believe that most Western physicists have been incapable to accept it, much less examine its consequences. In the physics that emerges from multiple simultaneous observations, all possibilities are real and physical. There are an infinite number of worlds, orthogonal to one another, and each world is continually splitting into additional such "worlds" at a stupendous rate. However, the orthogonal realities intercommunicate in the virtual state, that is, an observable in one reality is always a virtual quantity in each of the other realities. Thus one can have multi-level “continuities” and “discontinuities” at once, with no logical dispute. And it is precisely these levels of scalar vacuum, that lace together the discontinuous quanta generated by the relations of light with mass.
  13. Dec 5, 2003 #12
    Dear Forum members, especially spacestar,

    I apologize for the comments made earlier in this post.
    I will never post here again, I am ashamed of what I
    have done.

    Wishing everyone the best,

    Last edited: Dec 6, 2003
  14. Dec 5, 2003 #13
    How rude, I won't even distinguish your reply with a fitting answer.

    I wouldn’t expect someone with such a gross intellect (probably emotionally abused) to grasp my line of reasoning.


    I am sorry about this too.
    Last edited: Dec 8, 2003
  15. Dec 7, 2003 #14
    But this raises some questions about free will, right?

    I don't think so. It seems to me that ambient is saying the same thing as spacestar. To the best of my understanding, you're both saying that outside of parellel universe created by intervention in time, if time travel is possible than to avoid paradoxes(which then render time travel impossible), time travel is self-fulfulling prophecy. Your only helping things along, right?

    I don't see it as a violation of freewill, especially if it's as you two are saying. If you want to go back in time and change your option with the rock, that would be a violation of your own freewill. The you-now trying to violate the option that the you-then made, even if you came to regret the choice made, bottom line fact is you wanted to make that choice then.
  16. Dec 7, 2003 #15
    Excuse me, I am ignorant, but can someone plz explain this to me??
  17. Dec 7, 2003 #16
    sorry, i am stupid

    Can u give me an example of Amplitude? And explain Schrodingers cat theory?
  18. Dec 7, 2003 #17


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    An amplitude is a number that quanum mechanics gives that describes a quantum state. It can be turned into a probability. It gives the probability for some quantum event to come out a particular way. Now the amplitude numbers are complex numbers, that is they involve the square root of minus 1. Don't ever let anyone tell you complex numbers ar3e not just as good as real numbers or that minus 1 doesn't really have a square root.

    The point is they can be added together and you can get the sum of two different quantum states. This is called a superposition of states.

    Now Schroedinger, the great physicist who invented the basic equation of quantum mechanics was unhappy with what other physicsts had done with his theory. He thought the amplitude was some genuine field, like electromagnetism or gravity, but the others said it was just an abstraction, and a particle didn't really have an amplitude tilll you measured it. Till then it could be in a superposition of several amplitudes, you would never know.

    So Schroedinger, who was a cat lover, thought up an example that would be so silly it would convince everyone that the other physicsts were wrong. Suppose, he sad, you put a cat in a box, and with it a device that has exactly a fifty percent chance of releasing a poison gas that will kill the cat. Then you close up the box. Now, he said, you can't observe the cat, so it must, by your ideas, be in a superposition of states; and the two possible states are alive and dead. So the cat is alive and dead at the same time! since that is stupid, the unobserved superposition idea must be wrong.

    People who describe the experiment and don't know the story think that Schroedinger really thought the alive-dead thing would happen, but he meant it as a reductio ad absurdum.
  19. Dec 8, 2003 #18
    Basically that’s what I’m saying (I’m not certain about ambient though) - that in a specific space-time continuum the time traveller does (in his own freewill according to the circumstances) what in fact happens at that point in time. I also think there’s no freewill violation here, like I was trying to argue.
  20. Dec 10, 2003 #19
    in a specific space-time continuum the time traveller does (in his own freewill according to the circumstances) what in fact happens at that point in time. I also think there’s no freewill violation here, like I was trying to argue.

    oh, OK. Point made.
  21. Dec 11, 2003 #20

    I still see no difference between my theory and yours. There was no need to be
    rude and insult someone else's intelligence. We are all mature people here,
    hopefully, and should treat each other with courtesy.

    Before I go back to going deeper into my theory, I have a question to everyone.
    While I understand the whole concept of multiverses, and how they might
    split and branch out if something is altered, the one thing I don't understand
    where does the energy and mass that creates those universes come from?
    What about the space?

    Can someone explain it in a coherent manner?

    I just happen to have a big problem with the multiverse theory. Because if it
    is true, there are trillions of universes created just from a way one person
    brushes his teeth in the morning. Every action, no matter how small, should
    create another universe, if we go by the multiverse theory. The number of
    universes becomes so absurdly large, that their existence becomes
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