Don't know where to put - logical proof the future is undetermined.

[Neverfly]

If I change the premise then I also change the conclusion, I'm only showing why we would be able to change the future if we knew about it. Obviously this is impossible in a hard determined universe, as such it is also impossible to have that message in the first place.

You never convinced me of why we wouldn't be able to change the future if we knew about it. Even in a hard determined universe, if we knew exactly our own future from any time, then we could change it. The message would have to be obfuscated in such a way that we didn't know about it until it happened, but then it isn't exact knowledge of the future...

The premise of my idea was never changed, I just showed my idea from a different perspective where the change of premise also changed the conclusion (the conclusion being that we can't change the future in a hard determined universe - if we don't know about it).

Can you at least see that it is reasonable to change the perspective in this way? I never abandoned my idea that it is impossible to know our own future in a hard determined universe, I'm just expanding on it in different perspectives and with different premises to see that whatever premise we have the idea still holds true.

I don't necromance, because the idea was never dead.

The thread is there and can be read. Whether you were convinced or not is a moot point.
You did change the premise-In order to have it fit your conclusion. You changed it to: Indeterminant universe.

[DaveC426913]

What you are talking about involves the difference between the Newtonian deterministic universe and the Quantum Mechanical indeterminate universe.

When our model of the universe was Newtonian, where every bit of matter was a little billiard ball whose trajectory could be in principle, predicted with accurate enough instruments, it could be shown that the future could - at least in principle be predicted.

Turns out do do not live the Newtonian universe. We live in a universe where the Heisenberg Uncertainty Principle applies. And the implication of HUP is that we cannot - even in principle - predict the trajectory of particles to an arbitrary degree of accuracy.

QM has put the nails in the coffin of the deterministic universe.

[Neverfly]

What you are talking about involves the difference between the Newtonian deterministic universe and the Quantum Mechanical indeterminate universe.

When our model of the universe was Newtonian, where every bit of matter was a little billiard ball whose trajectory could be in principle, predicted with accurate enough instruments, it could be shown that the future could - at least in principle be predicted...

QM has put the nails in the coffin of the deterministic universe.

Dave, just to expand on this a bit...

Determinant or not- STATUS: Unknown.

We are currently unable to determine- well, we would be in a Newtonian model as well. Even in a Newtonian model, there are just too many factors.

As it is, our current theory of QM is based in a great deal on how we have to measure the microscopic in a macroscopic world.
I think that a great deal of the paradoxes and puzzles to be solved are due to this.

So, we don't really know if the Universe is determinant or not. We know that because of our current inability to measure- that it is not possible for us to determine the Universe. Which isn't really any different from Newtonian, as the O.P. describes- we'd still need omnipotent knowledge of all particle positions etc. But an inability to measure does not necessarily mean that the actuality follows our models of the actuality.

That really is not relevant as the O.P.'s on both threads based their concept on, "Even if it IS possible to determine- we cannot as knowledge of the result would change it."
They were never about whether it's determinant or not.
This was, incidentally, the change of Premise that Cyperium employed at the end. Removed the "Determinant" factor and then continued to the conclusion. I find that very telling, myself.

[DaveC426913]

We are currently unable to determine- well, we would be in a Newtonian model as well. Even in a Newtonian model, there are just too many factors.

A Newtonian universe allows one - in principle - to plot the course of every particle in it. It does not matter if it's really really hard. The point is we can can pinpoint as close as our technology and determination allows, all the way to infinity if we had enough time and technology.

The Newtonian universe has been deprecated.

QM is the universe we do live in. And in this universe, it is not possible - even in principle.

As it is, our current theory of QM is based in a great deal on how we have to measure the microscopic in a macroscopic world.
I think that a great deal of the paradoxes and puzzles to be solved are due to this.

Let's be clear. The uncertainty in QM is not a measurement thing. It is not merely a matter of better sensors.

You cannot - even in principle - know the position and momentum of a particle to a greater accuracy than Heisenberg's formula shows. The reason you cannot know is because the information is not there to know. A particle does not have a specific position; it is smeared out in space.

Since you cannot have a particle's position and momentum to more than a certain degree of accuracy, you cannot predict its future trajectory. It's trajectory expands as a cone the farther you project into the future.

[Neverfly]

Let's be clear. The uncertainty in QM is not a measurement thing. It is not merely a matter of better sensors.

You cannot - even in principle - know the position and momentum of a particle to a greater accuracy than Heisenberg's formula shows. The reason you cannot know is because the information is not there to know. A particle does not have a specific position; it is smeared out in space.

Since you cannot have a particle's position and momentum to more than a certain degree of accuracy, you cannot predict its future trajectory. It's trajectory expands as a cone the farther you project into the future.

This is off topic as the thread requires determinism for its premise.

But this is a very interesting topic and I'd be happy to hear your thoughts in a thread of it's own...

[DaveC426913]

This is off topic as the thread requires determinism for its premise.

No, it addresses the OP's question directly and conclusively. I'll even quote it:

if you were to know the position of every particle and whatnot in the universe ... you could predict exactly what would happen tomorrow.

This premise is known to be false - not practically, or even hypothetically - it is false in principle.

So any argument based on it is dead in the water.

The OP has said: "If the laws of physics were not the laws of physics, what would the laws of physics be?" They might as well have said "if we were to grant the existence ghosts and unicorns, could we know the day of our own death?"

[Neverfly]

No, it addresses the OP's question directly and conclusively. I'll even quote it:



This premise is known to be false - not practically, or even hypothetically - it is false in principle.

So any argument based on it is dead in the water.

The OP might well have said "if we were to grant the existence ghosts and unicorns, could we know the day of our own death?"

Now, you're just being difficult.
This is philosophy, not physics. The Philosophy aspect is "If such were true..."

If you want a mindless argument over it- I won't give you one. This is how it is.
If you want to discuss the Actual Physics: Start an Actual Thread.

Thanks.

[DaveC426913]

If you want a mindless argument over it-

Wait, when did it become mindless? I thought we were discussing? Because I have made a strong point that can't easily be brushed aside, that doesn't constitute a mindless argument does it?

I am not trying to be difficult. I see this as the critical issue.

Now, you're just being difficult.
This is philosophy, not physics. The Philosophy aspect is "If such were true..."

I suspect that the OP wants an answer that is compatible with the world as we know it. I suspect that, if the OP were informed of a simple and explicit physical property that forbids exactly what he's asking about, that would satisfactorily answer his question.

Like I said, any discussion on predictability of the future will somehow have to address HUP. It could be merely a matter of saying "Okay, let's ignore HUP." But the OP will have to suspend a given law of physics explicitly. We, as responders can't just assume unilaterally that we can dispense with any laws we wish.

Why don't we leave it to the OP to decide what he intended?

[Cyperium]

The thread is there and can be read. Whether you were convinced or not is a moot point.
You did change the premise-In order to have it fit your conclusion. You changed it to: Indeterminant universe.

The premise is changed naturally if we know the future, my point has always been that if the universe is hard determined, then a message that reveals someones future would still enable that person to change it, and hence the universe can't be hard determined even if that was the nature of the universe - if such a message does exist.


You went on to say that whatever the message said it MUST come true, that would mean that if I got to know my own future then some extra-ordinary events would have to happen in order to stop me from changing what I know about. If I read that I will brush my teeth the first thing tomorrow then that has to come true, even if I decide - based on that knowledge - not to brush my teeth. The prediction can't change itself to reflect my change of action, and that is the downfall for the prediction in a hard-determined universe, and shows that either the universe can't be hard-determined or it can but then there must be no such message.

Either way, one of the premises must be false, both can't be correct.

If such a message would exist in a hard determined universe, then the existence of the message itself would actively change the universe to become soft determined. There's no other way if the message did reveal exactly how the events would unfold in a hard determined universe, as even the slightest change I make to the "plan" would make it soft-determined instead. The idea itself changes the premise, I'm just arguing to make you see why.

[DaveC426913]

The premise is changed naturally if we know the future, my point has always been that if the universe is hard determined, then a message that reveals someones future would still enable that person to change it, and hence the universe can't be hard determined even if that was the nature of the universe - if such a message does exist.


You went on to say that whatever the message said it MUST come true, that would mean that if I got to know my own future then some extra-ordinary events would have to happen in order to stop me from changing what I know about. If I read that I will brush my teeth the first thing tomorrow then that has to come true, even if I decide - based on that knowledge - not to brush my teeth. The prediction can't change itself to reflect my change of action, and that is the downfall for the prediction in a hard-determined universe, and shows that either the universe can't be hard-determined or it can but then there must be no such message.

Either way, one of the premises must be false, both can't be correct.

If such a message would exist in a hard determined universe, then the existence of the message itself would actively change the universe to become soft determined. There's no other way if the message did reveal exactly how the events would unfold in a hard determined universe, as even the slightest change I make to the "plan" would make it soft-determined instead. The idea itself changes the premise, I'm just arguing to make you see why.

All of this is based on a premise that we have free will. That has not been shown to be true.

It is conceivable that getting a message from the future would not grant you the ability to change your course of action.

[Neverfly]

Wait, when did it become mindless? I thought we were discussing? Because I have made a strong point that can't easily be brushed aside, that doesn't constitute a mindless argument does it?

No, it doesn't...
But I also made a strong point about how it relates to this thread.
The thread is not about Unicorns and the like.

I suspect that the OP wants an answer that is compatible with the world as we know it. I suspect that, if the OP were informed of a simple and explicit property that forbids exactly what he's asking about, that would satisactorily answer his question.

This may be true- that is not how I read the O.P. Perhaps he can weigh in on that. Would be an interesting thing to hash out. And if I have misconceptions, I'm open to hearing how and what they are.

Why don't we leave it to the OP to decide what he intended?

If he returns anytime, soon... that is fine with me.

[Cyperium]

All of this is based on a premise that we have free will. That has not been shown to be true.

Even so, knowing what will happen tomorrow doesn't take away my ability to choose my actions based on that knowledge. All actions are in some way based on information and I can't see any way that the information (knowledge) about the future doesn't influence that future. How could I know that I would do something but be unable to change it, if I have all the necessary information?

Would I loose my sense of free will and instead only come to observe my actions?

If so, then how can knowledge make me loose that sense of free will, when there is nothing forcing me into any direction?

Keep in mind, that even though I know what I will do, nothing has actually changed to restrain me from doing anything else.

It is conceivable that getting a message from the future would not grant you the ability to change your course of action.

I don't find it conceivable. It has considerable problems. One being that even things that should be very easy to change, suddenly would become impossible to change.

One simple thing that the message could say is that you'll raise your finger in five seconds, then I could choose not to. But then that's what the message would have to say instead but it can't undo the first prediction. Such simple things do occur all the time in our lives. I could just look at what leg I would start with when walking and choose the other leg to start walking instead. The message would then have to state that I used the other leg instead, but if it didn't in the first prediction then it can't undo that.

The sense of free will is to have options (I can do this, instead of that), if I knew everything about my future then suddenly I would feel like I have no options, even though options would be abundant (as they normally are in our ordinary lives).

How can I conceive of having no options?

[DaveC426913]

Even so, knowing what will happen tomorrow doesn't take away my ability to choose my actions based on that knowledge. All actions are in some way based on information and I can't see any way that the information (knowledge) about the future doesn't influence that future. How could I know that I would do something but be unable to change it, if I have all the necessary information?

Would I loose my sense of free will and instead only come to observe my actions?

If so, then how can knowledge make me loose that sense of free will, when there is nothing forcing me into any direction?

Keep in mind, that even though I know what I will do, nothing has actually changed to restrain me from doing anything else.


I don't find it conceivable. It has considerable problems. One being that even things that should be very easy to change, suddenly would become impossible to change.

One simple thing that the message could say is that you'll raise your finger in five seconds, then I could choose not to. But then that's what the message would have to say instead but it can't undo the first prediction. Such simple things do occur all the time in our lives. I could just look at what leg I would start with when walking and choose the other leg to start walking instead. The message would then have to state that I used the other leg instead, but if it didn't in the first prediction then it can't undo that.

The sense of free will is to have options (I can do this, instead of that), if I knew everything about my future then suddenly I would feel like I have no options, even though options would be abundant (as they normally are in our ordinary lives).

You're arguing the case of free will. It is an argument with a very long and coloured history. And it has not been resolved yet.

So nothing's changed. Your 'predict the future argument' is based on the premise of free will, and that's not shown to be true yet.

---

The argument against free will (very abbreviated): It is possible that every decision you make is already determined - by your past experiences and your current neuro-chemical state. This includes your feeling that you are acting of your own free will. But you may not be.

In this Newtonian-deterministic universe, if I could duplicate every one of those molecules exactly as they are in you, every duplicate instance of you would make exactly the same decision on which leg you start to walk on, including deciding to change your mind the second time. Thus, since your actions are predictable, you don't have free will, even though you think you do.

(Please don't take this up as a separate argument, I only provide it as a teaser. You'd have to read a more comprehensive argument against free will to refute it properly.)

[Cyperium]

You're arguing the case of free will. It is an argument with a very long and coloured history. And it has not been resolved yet.

The thing is, it doesn't have to be a argument of free will, it can just as well be a argument that the message itself isn't possible in a hard-determined universe.

I have shown that such a message wouldn't be possible to make in the first place, and it isn't surprising that the subject reading about his own future is what makes it impossible. It has the same arguments as the case of free will but from a different perspective and doesn't directly involve free will (free will is not what makes it impossible). It is simply based on the fact that the future of the message isn't available before the future is predicted, as such any events that unfolds in the future because of the knowledge of the future can't be predicted.

The knowledge of the future (in the future) just can't be ignored, and the knowledge of the future is always unknown when the process of predicting it gets to that point (as it hasn't predicted the future beyond that point yet). As such it can never be predicted what the reader of the future will do based on what he reads, because what he reads is unavailable to the prediction when it gets to that point.

In conclusion; even though we would have all variables, there is no way to determine the future of the one reading the message, because when the determination process comes to that moment then it doesn't know what he reads and can't predict that line of events further.