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#11 octopuppy

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Posted 28 February 2008 - 11:38 PM

Continue on with this thought.Who or what predetermined the future.

My understanding of physics is this:
Newtonian physics gives us a model of a clockwork universe where everything is predetermined. If only we knew the current state of the universe in sufficient detail we could predict the future with complete certainty.
Only trouble is, it doesn't work like that.
Quantum mechanics is something I'm presently trying to get my head round (more the philosophical implications than the detail - I'll leave that to the physicists). Particularly the idea of decoherence interests me. In simple terms, this is when a particle stops acting like a wave and starts acting like a particle. It's triggered by interaction with other particles (ie. measurement or detection). A wave spreads out in all directions, is in many places at once. A particle has a particular location. The wave aspect (which is very real, in the sense that it has interference patterns for example) describes the probability of the particle being at any given place, and decoherence is when the particle "chooses" to be in one place based on that probability wave. That's a gross oversimplification but I think it's a pretty good model for a non-physicist to work with. The point I'm getting at is that it seems to be a really random event. The probability is predictable, the actual outcome is not. This sort of non-deterministic behaviour is what Einstein was railing against when he said "God does not play dice".
I personally find a lack of determinism troubling. A random event leaves more to be explained in some sense - what decides that the random outcome will be this and not that? Some people might be happy to give God the job, but this is no explanation in my opinion. The most elegant model, in my mind, is one in which all possible outcomes occur in an equally real sense. We cannot experience all these realities interactively (ie. one reality cannot be aware of another). Effectively we have infinitely many parallel universes branching into infinitely many more at every instant of time. Looking at one branch it seems that the course that branch took was random, but in fact all available courses were taken. On some level that may be mind-boggling, but it's also very simple.
The implications are interesting, for example time travel paradoxes are no longer paradoxes, since they invariably assume one course of events. Every possible course our lives could take is taken, by ourselves, in a very real sense. Any bad decision you ever made, which could have been done better, was done better, by you. Not in this branch of reality but another equally real one. It's reassuring to think that. But this does not give us Free Will, since your actions remain predetermined. But what is also predetermined is that you will live out every possible course of action you could do. Who needs Free Will when you can have every possible future, and not be stuck with just choosing one. Now that's having your cake and eating it (and not having it, and having it but not eating it).

Enough. Time for someone else's thoughts.
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#12 bociniki

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Posted 29 February 2008 - 04:27 AM

I don't think that there are really any random actions or events in this world. A machine could be made to flip a coin or to roll a dice and get the same every time. I think that peoples actions are 'determined' by their history and their personality. Kind of like the green door example, there is the choice, and it isn't 'predetermined' but, if there were some kind of observer who studied humans, and nature, he could predict what would happen.

On the many universes that you were talking about, if I understand what you are saying, then all the other people in this world could be 'living' in another dimension and I could be the only person who is truly living in this world. That doesn't seem logical some how but I am not sure how yet. I will keep thinking on that.
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#13 ClattoVerataNicto

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Posted 29 February 2008 - 05:23 AM

All of us have one certain destiny in this mortal coil, but the universe will outlive us all.
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#14 BoscoRanger

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Posted 29 February 2008 - 05:31 AM

There’s a fly in your ointment. It is true that most people’s actions can be determined with much certainty. If you were to throw someone with mental illness in the mix , their actions could be anything then predictable even in view of their history.
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#15 Duh Puck

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Posted 29 February 2008 - 09:04 AM

Octopuppy, have you been watching BBC documentaries again? :rolleyes:

I'm still interested in this topic and have enjoyed the observations so far, but I just haven't had much time to participate lately. Don't go away.

Edited by Duh Puck, 29 February 2008 - 09:05 AM.

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#16 octopuppy

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Posted 29 February 2008 - 09:17 AM

I don't think that there are really any random actions or events in this world. A machine could be made to flip a coin or to roll a dice and get the same every time.

Maybe, maybe not. Flip it high enough or roll it far enough and quantum unpredictability could come into play. The apparent randomness of quantum mechanics can't be ignored. It works its way up into large scale systems.

I think that peoples actions are 'determined' by their history and their personality. Kind of like the green door example, there is the choice, and it isn't 'predetermined' but, if there were some kind of observer who studied humans, and nature, he could predict what would happen.

When I say 'predetermined', all I mean is that the future is determined by the past. I think it has to be, unless there is some other factor like randomness involved.

On the many universes that you were talking about, if I understand what you are saying, then all the other people in this world could be 'living' in another dimension and I could be the only person who is truly living in this world.

Wow, that's not at all what I meant but it's a curious idea. Our universe is all that we can experience or interact with, so other people are in the same one as you, otherwise you wouldn't be able to see them. On the other hand, you can not experience an alternative future, or an alternative present based on something that happened differently in the past. But that's not to say they don't exist. These are the parallel universes I'm talking about. Other versions of the whole universe containing other versions of you (providing you haven't died in them) and everybody else, living out a different story that branched off from yours at some point in time.

There’s a fly in your ointment. It is true that most people’s actions can be determined with much certainty. If you were to throw someone with mental illness in the mix , their actions could be anything then predictable even in view of their history.

I wasn't talking about predictability. I'd say most people's actions are unpredictable in general. Given the complexity of the human brain it's understandable, and quantum mechanics suggests that there would not be predictability even if we could know all there is to know about someone's brain. What I'm saying is there's two ways to look at that. It's either random, or if all possible actions are carried out in parallel, it's deterministic in a sense (but not from the point of view of a single timeline). Since we're naturally predisposed to look at things from the point of view of a single time line you need to step back a bit to see the determinism.
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#17 octopuppy

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Posted 29 February 2008 - 11:14 AM

Octopuppy, have you been watching BBC documentaries again? :rolleyes:

I'm still interested in this topic and have enjoyed the observations so far, but I just haven't had much time to participate lately. Don't go away.

Thanks for the link, Duh Puck. That was very interesting. The physics I'm going from is a bit old-fashioned by comparison, but it's funny how the whole notion of parallel universes is suddenly gaining respectability. I'd say what was in that program is a whole different chain of thought, though. I may never have a good understanding of that kind of physics, though it struck me that the "parallel universes" mentioned there can actually interact with each other, which is a curious notion.
What I'm putting forward here is that the complete reasoning behind one particular kind of parallel universe is not beyond us mere mortals. All it takes is an attempt to understand wave-particle duality.
But you can also put forward arguments for parallel universes in even more mundane terms. Check out this quite readable paper by Max Tegmark, describing many different kinds of parallel universe. The "level 1" type depends on nothing other than infinite space with a reasonably homogeneous distribution of matter, which we seem to have. I don't think it does a terribly great job of explaining the quantum physics part so you feel like you really understand it, but I guess that's beyond the scope of the paper.
http://www.winterste.../multiverse.pdf
What really left an impression on me was the level 4 type, which sheds a little light on what makes real things real. If you could conceive of some other universe which was logically consistent, how could it not exist? What's so special about our universe that gives it the property of existence? Perhaps reality is a human invention.

Keep it real, people!
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#18 bociniki

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Posted 01 March 2008 - 04:58 AM

There’s a fly in your ointment. It is true that most people’s actions can be determined with much certainty. If you were to throw someone with mental illness in the mix , their actions could be anything then predictable even in view of their history.


What makes some one 'mentally ill' I don't know, but I would guess that they just don't think like most of us do, so, in our great brilliance, we say they are 'mentally ill' and put them in asylums. I would imagine that their actions actually do have a logical source, but we just can't see it.

What I was saying about the multiple realities was that everybody would be experiencing other worlds or realities so they couldn't be in yours. Let's take a very simple example. If I am walking with two friends and we come to a fork in the road, there are 8 possibilities. If I understand your theory correctly, at that moment 8 new universes would have been created. So let's say that I happen to choose the right fork with both of my friends in my reality but in their realities, they both go down the left fork. So now, they the physical person are in all the universes, but something is different about the one where they took the left fork, so in my reality, they aren't really there. After not very long, I could be the only true person left on this earth in my reality.
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#19 Duh Puck

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Posted 03 March 2008 - 04:20 PM

That leaves two possibilities:

1) Despite all this, the dice roll must come out exactly the same because there is only one future. May not be as unlikely as it seems in this scenario because by skipping forward one minute into the future and then returning to the present you have not done anything to change the course of history, just taken a sneaky peek at the result. The result you saw in the future was presumably rolled by you having returned to the present after seeing that result. There could be one consistent series of events here. We could come up with a paradoxical series of events by rolling the die then going back into the past to witness yourself doing that, when you hadn't been there the first time. That would probably change the outcome. But I'd rather not get too hung up on time travel paradoxes - it's a bit off topic, and paradoxes are paradoxes after all.

2) The dice roll turns out differently, as you suggest. The future in which the first result happened was real (you were there!), and the future in which the second result happened is certainly real, since that seems to be the one we're going forward with. But that still doesn't create a distinction between what is possible (many results) and what is real (many futures).

I think Duh Puck was suggesting the first of these scenarios, but we needn't necessarily dismiss the second.

Man, there are some juicy morsels left on the table in this thread, and I'm irritated that I haven't made time to consider them fully yet. You've really got me thinking octopuppy, and I wish I had more time to ponder this. Hopefully in the next few days ...

I will say that you are correct that I was referring to the first scenario, but I did want to make a small clarification. If you returned to the present time after gaining knowledge of the outcome of the dice throw, then I can't see how your possession of that knowledge would not alter your throw, and thus become a causal factor, if it's you who are throwing the dice. In that case, you end up with the typical paradoxes depicted in Back to the Future. In my initial post, however, I was thinking about it from the standpoint of a third party. What if you saw the outcome of somebody else's throw, then returned to the present, and observed without interfering in any way? In that scenario, I think it's more plausible to say that the possible outcomes are not affected by your knowledge, since there's no causality.

In any case, the main thing you've got my brain stuck on is the concept of determination due to the laws of physics. As I sit here, deciding what keys to press, I have to wonder whether or not my choices are truly the result of an unavoidable series of physical events. My gut reaction is no, but why? Since this question wanders into the realm of metaphysics and clearly has philosophical implications, it's impossible for me not to draw upon religious belief. However, while most Christians might be able to easily rationalize this as the effect of a spiritual soul influencing the material functions of a physical mind, this is not my belief. I believe that I am a soul, in the biblical sense, not that I have one, and that my thought processes are thus directly connected with the amazing function of my brain. If you were able to materially duplicate my exact physical structure, down to the quantum level, I believe you would have another me, complete with my memories and decision-making inclinations. If so, then my belief would be affected by the concept of determination due to physical laws. Is it possible that quantum fluctuations are the indeterministic loophole that God built into the system so as to enable free-will? Seems like a long shot, but an interesting point to ponder.

In any case, after reading what you said about Einstein's comment that "God does not play dice," and your own uncomfortability with indeterminism, I thought you might enjoy Stephen Hawking's comments on the topic, if you haven't read them already. Probably nothing you haven't already heard, but nicely summed up.
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#20 octopuppy

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Posted 04 March 2008 - 09:52 PM

What I was saying about the multiple realities was that everybody would be experiencing other worlds or realities so they couldn't be in yours. Let's take a very simple example. If I am walking with two friends and we come to a fork in the road, there are 8 possibilities. If I understand your theory correctly, at that moment 8 new universes would have been created. So let's say that I happen to choose the right fork with both of my friends in my reality but in their realities, they both go down the left fork. So now, they the physical person are in all the universes, but something is different about the one where they took the left fork, so in my reality, they aren't really there. After not very long, I could be the only true person left on this earth in my reality.


It's a wonderful thought, but observation would seem not to bear that out. If my friends disappear they can usually be found down at the pub, but not in a different reality, unless they manage to get a few pints in before I arrive.
Drollery aside, lets go through your example. If 3 people choose from a fork in the road there are 8 outcomes (not counting turning back etc). It's a bit oversimplified to say that 8 new universes are created. Really what I'm suggesting is that infinitely many new universes are created in every instant of time, and all variations on the 8 outcomes will each be played out in these, but that's a bit beside the point. Let's say we just pick eight. In one reality, everybody goes down the right fork. In another, you go down the left fork and your friends go right. In another, you go right, one of your friends goes with you and the other goes left. And so on. But there is no reality in which you go right and your friends cease to exist because that's impossible*. I think you're getting confused by the idea that there is one reality which is your reality. Not so. You exist in many realities. There are many equally real versions of you, so all realities are "yours" (except ones where you got run over by a bus last week). Same goes for your friends.

*Actually on consideration it probably is possible but extremely unlikely. In which case there is a reality in which that happens but if you're confused ignore this because it will only confuse you more. Bear in mind it is extremely unlikely.
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