Determinism

[pgrmdave]

I believe in strict determinism, that is, every event is the direct result of events before it. This means that all objects, including humans, are governed by cause and effect completely, with no free will. To me, it is the only logical conclusion when one thinks about our universe. However, I am aware that some people feel differently, and I'm curious as to how they logically defend Indeterminism.

[cwes99_03]

Well, the only flaw I can see in your argument is that if the world were strictly determined then all future events would be known, all history would be able to be determined completely, and Heisenberg would be completely wrong.

 

Instead look at it this way. All actions are heavily influenced by other events, but someone can still choose to go against the flow.

 

Now if you look at the world from a completely macroscopic viewpoint, then you'll see that gravity affects all and all affects gravity, and certain laws we can not decidedly change. However, if you get down to the microscopic and the quantum, my neurons firing are processed in my brain. If there was no processing going on then I could agree with you, but decisions are made in the processing, and even when our gut tells us to do one thing, we have the ability to do another. How do you explain this?

Certainly you are implying that everything is completely beyond our control. If so, what praytell do you see as the controling factor(s) behind our actions.

[pgrmdave]

Our nuerons 'processing' is determined by the laws of physics and chemistry. Your 'gut' never tells you anything - it's a bunch of organs, including the stomach, liver, intestines... Your brain never 'thinks', but merely contains loops that both affect the information that is coming in and are affected themselves by the information coming in. The illusion of decisions made is strong, but understandable by physics.

 

And yes, I believe that Heisenburg was wrong, that while is may not be possible for us to know a particle's position and velocity at the same time, the particle does have a position and velocity at the same time. As for why we cannot predict history 100% accurately, it's because we don't know the initial conditions, nor do we know all the information about everything. I believe that if we were to know the exact position and velocity of every bit of matter and energy in the universe, then we would be able to (given infinite mathematical prowess) predict history completely accurately. Of course, knowing that information is impossible, so that theory cannot really be tested.

[Buffy]

Two things to consider:

• Quantum effects are certifiably random. While there's some debate its pretty hard to justify the position that they have *no* effect on the macro world: for a very long time we have had devices that measure quantum randomness *specifically* to generate random numbers (e.g. beta particle counters watching radioactive elements decay) that are used to drive machines.
  
• Random inputs *do not* mean completely random behavior. Monopoly uses dice, but as long as you don't give people $500 for landing on Free Parking or $400 for landing on Go, you sure ain't playing Calvinball. Its *completely* ordered, and behaves in a rational fashion
  

Ergo, there's no real contradiction here: we can prognosticate a lot, but the Butterfly Effect will always surprise us...

 

Randomly,

Buffy

[Buffy]

And yes, I believe that Heisenburg was wrong, that while is may not be possible for us to know a particle's position and velocity at the same time, the particle does have a position and velocity at the same time.

Of course that doesn't mean Heisenberg was wrong, but what we do know is the "act of observing affects the outcome" which is the *really* weird thing, and you can get into logic loops trying to determine why you looked and if *that* act was predetermined, etc. ad nauseum....

 

I wish I could muster the energy to get my topic on fear of randomness going...just look at your *reasons* for desiring determinism dave! Something to ponder!

 

Existentially,

Buffy

[pgrmdave]

I don't know much about Quantum physics. I understand that many things at the quantum level appear to be random, but I'm not sure what (other than decay). Is it possible that these things could have causes that we are thus far unable to detect? It is a young science, and it seems to me that any system that is highly sensitive to initial conditions would seem random, if the society studying the system had inadequate equipment to both see the whole and the part.

[pgrmdave]

just look at your *reasons* for desiring determinism dave!

 

Well...The biggest reason I believe in determinism is because of how I view time. I don't agree with the concepts of 'past', 'present', and 'future'. Rather, I believe that all time is equal, with the past, present, and future all 'co-existing'. The illusion of the passage of time is due to the fact that at any given 'present', it has only been affected by its 'past'. Imagine if all time 'stopped' at any particular 'present' - you'd never notice, because your thoughts would be completely frozen, electrical current wouldn't run, everything would be 'frozen'. If time then 'started' again, you'd not notice. Imagine if time ran 'backwards' - you wouldn't notice because at any given 'present' you would only have been affected by its 'past'.

 

What this adds up to is a future that is as true as a past - as in, the past never changes, nor does the future. In order for that to be true, there must not be 'randomness' - only controlled chaos, i.e. something which appears random, but is in truth controlled somehow.

[InfiniteNow]

Leave common sense at home when thinking of QM. Our langage makes it hard too... "control," "predict," whatever...

 

It's not so much that the act of measuring changes the system, the interpretation (specifically the Copenhagen) is more that there is no system unless it's being observed. This is where the probability comes into it... You don't know if an electron is here there or somewhere else until you measure it, so it keeps this superposition of states whereby it's in each.

 

While I try to avoid seeing fatalism as valid, it may be... dunno. I do, however, like your post immediatly above regarding time. This is a concept into which I've devoted considerable resource. It's always right now.

 

Anyway, cheers. :cup:

[pgrmdave]

You don't know if an electron is here there or somewhere else until you measure it

 

But does that really mean that an electron isn't here, there, or somewhere unless you measure it? If I turn my back on my room, does it disappear? If I stop measuring a particle's position, does it disappear? Again, I don't really understand QM very well, but I do think that there are some ideas that are impossible to test, as they deal with observing vs. not observing. It is impossible to know what anything is like when not observed, but I think that it is reasonable to assume that it retains its basic properties. A particle may have a different position when we observe it than when we don't, but that doesn't mean that it has no position.

[Pyrotex]

I believe in strict determinism, ...and I'm curious as to how they logically defend Indeterminism.

There are many processes in the Universe that are chaotic. Another word for this is "non-linear". One scientist even said that all the "interesting" phenomena are non-linear. That means, the equation of their behaviour is an equation (usually a differential equation) that has at least one term squared (or with a larger exponent, but squared will do).

 

Let's pick a big easy example, billiards. The equation usually applied to rail shots is that angle into the rail equals angle out -- if spin is zero or ignored. Therefore, with a perfectly frictionless table and perfect rails, we should be able to predict the position of the cue ball after a perfectly known shot with infinite ease arbitrarily far into the future.

 

But the actual equation of bounce includes SOME flex in the rail and this introduces a tiny tiny term that is non-linear. You can make the term as small as you like but not zero -- or the cue ball woudn't bounce. This means that the error between actual position and prediction grows (by compound interest) on each bounce.

 

First bounce, you can predict the position to less than the width of a proton. By the 30th bounce, your error has grown to be larger than the table.

 

This is NOT, I repeat, NOT a flaw in our knowledge. Increase the accuracy of the initial condition infinitely. It doesn't matter. By bounce 28 or 32, the ball will essentially be in a "random" position and direction. You cannot even in principal get around this -- all because of that teeeeeeeensy term with the exponent.

 

Therefore the Universe cannot be determinate. Even an "omniscient god" could not predict the future states of non-linear processes. Like orbital mechanics, weather, chemical reactions, collisions, turbulence, etc, etc, etc....

[pgrmdave]

If we could know, with complete precision, everything having to do with that table - the balls, the stick, the air, the table, the rails - everything with complete precision, then we would be able to predict exactly what would happen. Again, though, we couldn't know everything, much less with perfect precision.

[InfiniteNow]

By the time you are able to "know" everything about the table, it's no longer the same table, nor are you the same observer.

[Queso]

By the time you are able to "know" everything about the table, it's no longer the same table, nor are you the same observer.

 

*shiver

[Pyrotex]

If we could know, with complete precision, everything having to do with that table - the balls, the stick, the air, the table, the rails - everything with complete precision, then we would be able to predict exactly what would happen. Again, though, we couldn't know everything, much less with perfect precision.

I'm sorry Program Dave, :confused:

but I just told you that it doesn't work.

I am really sorry to break the news. But at the heart of Chaos Theory is this kernel of truth: infinite infinite infinite infinite knowledge does NOT give arbitrarily long predictability. :cup:

It's built into the Universe. No. It's worse than that.

It's built into Reality, into Existence itself.

The Universe is not a clockwork mechanism after all, but a bag of marbles.

 

InfiniteNow is righter than he dreams.

[InfiniteNow]

By the way, if you don't understand it too well, you belong to a pretty large (and otherwise often very intelligent) group of people. Heisenberg's Uncertainty principle really is at the heart of many QM issues.

 

You cannot know p and q with any real precision when looking at both, but oddly, when looking at only one, you can know it very well. I think that Dirac actually found this relationship before Heisenberg, but I don't have my book around me to confirm.

[pgrmdave]

By the time you are able to "know" everything about the table, it's no longer the same table, nor are you the same observer.

 

That's dealing with the physical limitations of a human, I'm talking about theoretically 'knowing' it all, not necessarily testing it and finding out everything about it.

 

But at the heart of Chaos Theory is this kernel of truth: infinite infinite infinite infinite knowledge does NOT give arbitrarily long predictability.

 

I thought that the Chaos Theory was mostly about the sensitivity to initial conditions - that since every system is highly sensitive to its initial conditions, right down to the subatomic particles, then it appears chaotic, but that in truth, everything was determined.

[pgrmdave]

You cannot know p and q with any real precision when looking at both, but oddly, when looking at only one, you can know it very well.

 

I agree with him on this, I simply disagree with the idea that because we can't know it, then they cannot co-exist. Whether or not we can observe them, they exist. Whether or not they have, at any given present, any effect on anything does not affect their existance.