Causation and randomness

Originally posted by twhitehead
It seems this issue is deeper than I thought and that more people than I realized have the same hang up over the universality of causation. I now realize that it really goes back to the old question "Does God play dice?". I believe Einstein would side with predictability but could not prove it, and Hawking would side with unpredictability. (If I am wrong ...[text shortened]... ead to the great difficulty scientists over the years have had accepting quantum mechanics.

In the scientific method, you always apply 3), like I claimed earlier in the thread. You won't find a single theory in physics that relies on "causes".

Your dice example is a bit clumsy, I think, because quantum fluctuations don't really play a (direct) role in rolling dice (since the non-quantum effects dominate, like air flow around the dice and the "classical" force applied by one's hand). I think I get what you're trying to say (quantum fluctuations having an emergent effect on a macroscopic scale), but really you ought to find a full quantum-mechanical description of the system at hand before you can draw any conclusions on "true" randomness (the random elements of the Born rule may or may not be a sign of such true randomness, remember that when you're taking the square of a wavefunction you're actually throwing away some information i.e. the phase). Now the question is, can you find a description of a complex system including a "measurement" process akin to the particle-in-a-well, i.e. in a deterministic fashion? "Measurement" is actually a - convenient, and necessary - cop-out because you don't want to - and in practise can't - find a quantum description of the entire system including the thing doing the "measuring" - are you getting my drift?

As for Einstein and his dice, you ought to read up on something called the EPR paradox and Bell's inequality - it's too much for me to explain here and I'm sure others can do it better than me.

Just to backup my basic claim:
http://www.hawking.org.uk/index.php/lectures/64

Thus, the future of the universe is not completely determined by the laws of science, and its present state, as Laplace thought.

Stephen Hawking

So to summarize so far:
1. My die throw example has been attacked (and rightly so) and may be entirely a result of initial conditions and potentially predictable (given initial conditions).
2. Quantum mechanics however implies that some events are not predictable even in theory and the universe is not fully deterministic.

Now my basic claim for the thread is not:
The universe is non-deterministic.
My claim is:
There is no reason to believe the universe is deterministic.

So does anyone still feel I haven't proved my case? Does anyone have a reason to believe (other than via religious writings) that the universe is deterministic? (ie everything must have a cause).

Originally posted by twhitehead
So to summarize so far:
1. My die throw example has been attacked (and rightly so) and [b]may be entirely a result of initial conditions and potentially predictable (given initial conditions).
2. Quantum mechanics however implies that some events are not predictable even in theory and the universe is not fully deterministic.

Now my basic claim fo via religious writings) that the universe is deterministic? (ie everything must have a cause).[/b]

I would say I'm a determinist and hold to the notion perhaps science hasn't built up a full picture of what's 'going on' at the quantum level - indeed there are a number of different interpretations of quantum physics and a few that perhaps work in my favour - though physics isn't my subject so I cannot elaborate too much here.

For me to assume a non-deterministic universe I have to convince myself that there are some events which occur at some level independent of all other inputs (even as a consequence of their own prior actions individually) in the four dimensions we perceive or in any othersReveal Hidden Content (for any amount of dependency undermines randomness) - and I have to do this with little empirical substantiation (as I said, I'm not entirely convinced we have a full scientific picture of the micro universe that cannot be refined later on as we acknowledge more variables)

To me occam's razor says neglect non-causation.

Originally posted by twhitehead
So to summarize so far:
1. My die throw example has been attacked (and rightly so) and [b]may be entirely a result of initial conditions and potentially predictable (given initial conditions).
2. Quantum mechanics however implies that some events are not predictable even in theory and the universe is not fully deterministic.

Now my basic claim fo via religious writings) that the universe is deterministic? (ie everything must have a cause).[/b]

Yes. Copenhagen interpretation (the most standard) clearly states that although our best description of the universe so far includes randomness this doesn't mean that the universe features randomness. We simply cannot distinguish the two alternatives because measurement is imperfect. Claiming that science has shown that the universe is stochastic is a falsehood. We just don't know.

http://en.wikipedia.org/wiki/Copenhagen_interpretation

This may also be of relevance to this thread:
http://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics

Originally posted by Palynka
Claiming that science has shown that the universe is stochastic is a falsehood. We just don't know.

I am not claiming that the universe is stochastic (or that science as shown it to be such). I am claiming that we 'just don't know' and therefore there is no reason to think that it isn't.

Interesting that wiki claims that the Copenhagen interpretation is not agnostic on Determinism. That's not how I understood it before (nor how I read the text), which was that quantum mechanics were indeed indeterministic but this could be due to the nature of measurement or the nature of the universe (of which we couldn't distinguish because of measurement limitations). 😕

Maybe some physicists here can chip in on this.

Originally posted by twhitehead
I am not claiming that the universe is stochastic (or that science as shown it to be such). I am claiming that we 'just don't know' and therefore there is no reason to think that it isn't.

I see, so I think we agree on the basic premise. Your OP does suggest this but then on subsequent posts you seem more assertive about the random nature of some events, which threw me off. Sorry. I need to read the whole thread again...

Originally posted by Palynka
I see, so I think we agree on the basic premise. Your OP does suggest this but then on subsequent posts you seem more assertive about the random nature of some events, which threw me off. Sorry. I need to read the whole thread again...

Yes, I probably did go beyond my OP claim in places.
I think it is an interesting question: If it can be shown that certain events are truly random, then does that definitely mean 'no cause'?

Originally posted by Palynka
Interesting that wiki claims that the Copenhagen interpretation is not agnostic on Determinism. That's not how I understood it before (nor how I read the text), which was that quantum mechanics were indeed indeterministic but this could be due to the nature of measurement or the nature of the universe (of which we couldn't distinguish because of measurement limitations). 😕

Maybe some physicists here can chip in on this.

The Copenhagen interpretation basically takes the Born rule at face value and assumes that, as long as we don't find some other, broader explanation, its randomness is a feature of nature.

I'm not sure you fully understand what is meant by "measurement" - it's simply a phrase for "interaction with a macroscopic object", not necessarily involving something on a gauge. If a "macroscopic object" interacts with a particle (or many-particle wavefunction) in such a way as to be influenced by some observable, then the Born rule will give you the probability that this observable has some eigenvalue. The problem with the Copenhagen interpretation is that it does not take into account that you don't know the wavefunction of the macroscopic object doing the "measuring".

Originally posted by twhitehead
I am not sure if this should be here or in Science, but it is about things usually discussed here.
This claim comes up over and over in this forums:
[b]"Everybody knows that everything in the universe is caused"
or its cleverly posed in another form:
"Show me something that is known not to have a cause"

It is my claim that the vast major ...[text shortened]... iming he is eternal - and thus avoiding the problem of having a time prior to his existence.[/b]

At the other thread you said that your identity is an ever changing blurry edged entity comprising mostly your consciousness, which is a complicated pattern of information that arises from your brain. Cool and acceptable, although I would argue that these pieces of info arise from your body-dependent mind.

Here, you merely imply an injection of your personal meaning by means of conducting your specific choices independently of the associated deterministic physical phenomena! Consider the result of the dice for free will; each time you throw it in a certain way the result is determined by specific actions which, by definition, are algorithmic and deterministic. Each -random- outcome depends on these deterministic settings, and thus each random outcome is the net result of deterministic processes acted on by the hidden quantum logic implied in firstplace. However, once more, it’s only Us (the mind-only generator of whatever we perceive, is our consciousness). We use to think and to act in a deterministic fashion but occasionally our thoughts and our actions are so strange that we end up totally surprised; in fact, we ignore that all we are doing is to cut through the potentiality for storing potentialities during our way to the realm of the stored potentialities; from there, we just find ourselves deep in the realm of the conventional material world of our dualistic experience -and here lays the outcome/ result (in our case: the random result each time we throw a dice) we are experiencing with our 6 senses.
In other words, we ignore that from the sphere of the fundamental void wavefunction we cut through the uncollapsed wavefunction, and from there to the collapsed wavefunction. Methinks we probably need a new logic to describe things the way we perceive them; this logic could well be the quantum logic
😵

Originally posted by KazetNagorra
The Copenhagen interpretation basically takes the Born rule at face value and assumes that, as long as we don't find some other, broader explanation, its randomness is a feature of nature.

I'm not sure you fully understand what is meant by "measurement" - it's simply a phrase for "interaction with a macroscopic object", not necessarily involving some ...[text shortened]... hat you don't know the wavefunction of the macroscopic object doing the "measuring".

Yes, I understand what it means but you're right that I abused the term. What I meant is that it also has implications as to how much of nature is knowable, although I should have distinguished it more clearly.

As for the CI, it's not at all clear to me that what is meant by it. See here:
http://plato.stanford.edu/entries/qm-copenhagen/

For example, Bohr clearly believed that we could not distinguish if randomness was a feature of nature. ("Bohr accepted the Born statistical interpretation because he believed that the ψ-function has only a symbolic meaning and does not represent anything real."😉.

Originally posted by twhitehead
I think it is an interesting question: If it can be shown that certain events are truly random, then does that definitely mean 'no cause'?

Even if there is stochasticity in certain events, I would still imagine a strong dependence on the conditions surrounding it so I wouldn't be comfortable calling them "without cause".

Causality is a convenient way to determine the relative importance of certain actions in determining future states. But in the real world, interdependence is the name of the game, so causality is more of an abstract thinking tool than anything else.

Originally posted by Palynka
Yes, I understand what it means but you're right that I abused the term. What I meant is that it also has implications as to how much of nature is knowable, although I should have distinguished it more clearly.

As for the CI, it's not at all clear to me that what is meant by it. See here:
http://plato.stanford.edu/entries/qm-copenhagen/

For example, B ...[text shortened]... hat the ψ-function has only a symbolic meaning and does not represent anything real."😉.

Hmm yes, well interpretations differ within the CI itself, of course.

The Wiki has this quote that I largely agree with:

Steven Weinberg in "Einstein's Mistakes", Physics Today, November 2005, page 31, said:

All this familiar story is true, but it leaves out an irony. Bohr's version of quantum mechanics was deeply flawed, but not for the reason Einstein thought. The Copenhagen interpretation describes what happens when an observer makes a measurement, but the observer and the act of measurement are themselves treated classically. This is surely wrong: Physicists and their apparatus must be governed by the same quantum mechanical rules that govern everything else in the universe. But these rules are expressed in terms of a wave function (or, more precisely, a state vector) that evolves in a perfectly deterministic way. So where do the probabilistic rules of the Copenhagen interpretation come from?

Considerable progress has been made in recent years toward the resolution of the problem, which I cannot go into here. It is enough to say that neither Bohr nor Einstein had focused on the real problem with quantum mechanics. The Copenhagen rules clearly work, so they have to be accepted. But this leaves the task of explaining them by applying the deterministic equation for the evolution of the wave function, the Schrödinger equation, to observers and their apparatus.

The problem of thinking in terms of classical measurements of a quantum system becomes particularly acute in the field of quantum cosmology, where the quantum system is the universe.[18]