- #36
entropy1
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Then (and I know I am going a littlebit off topic here, but it is relevant in this context), I guess I don't really understand what 'local realism' is. Can someone explain that in a relatively simple way to me?
entropy1 said:Then (and I know I am going a littlebit off topic here, but it is relevant in this context), I guess I don't really understand what 'local realism' is. Can someone explain that in a relatively simple way to me?
bhobba said:See:
http://www.johnboccio.com/research/quantum/notes/paper.pdf
Thanks
Bill
Let us define a “counterfactual” theory [10, 11] as one whose experiments uncover properties that are pre-existing. In other words, in a counterfactual theory it is meaningful to assign a property to a system (e.g. the position of an electron) independently of whether the measurement of such property 2 is carried out.
entropy1 said:So, if there is no realism, a particle may not even exist if not measured?
entropy1 said:What does the qualification 'local' mean in this context?
entropy1 said:And why should a specific particle exist when not measured?
bhobba said:Those types of questions belong to philosophy and that discipline never reaches any conclusions. That's one reason science and mathematics divorced itself from it many many moons ago (another was great philosophers like Kant claimed all sorts of things that others like Gauss showed were rubbish using not philosophy but math and science). Don't worry about them.
entropy1 said:I think that physicists that want to endorse local realism are already operating in de philosophical discipline.
bhobba said:That's exactly what they haven't done because, as you can see in the link I gave, they carefully defined their terms.
Thanks
Bill
entropy1 said:I haven't read it yet, but I searched the document for 'local realism' and found nothing...??
I don't know of any, there may be none. Unless some superdeterminism wacko types. If you've come to that, one can consider the basics - we always refract the outside world(whatever that is) through a brain. That brain always perceives a classical reality and, as far as we know, it originated in an entirely quantum world. We know from other fields of science that we perceive reality as we are structured, not as it fundamentally is(subject to constant debate). Reality as is known today is basically is like this -> quantum reality - brain - classical world. Why nature chose to be like this no one knows, but we surely got to know better than trust naïve realism and its variety local realism.entropy1 said:I think that physicists that want to endorse local realism are already operating in de philosophical discipline.
If initial conditions determine final conditions its causal.
Bil
Edward Hunia said:Thats determinism.
Edward Hunia said:By virtue of superposition, which is more realistically representing a natural system, there is cause.
Edward Hunia said:because that's how math works. at its primary function, a formula is just a constraint that allows the determination of some result. nature follows natural constraints.
Bruno81 said:we always refract the outside world(whatever that is) through a brain.
That 'weird' view of the world is a non-Newtonian worldview. The Newtonian worldview is dead wrong and a worldview of the 18 century. Oh wait, we don't have an established scientific worldview today :). No, seriously, I shared this post to provoke thinking, we really need to examine the basics in light of the modern developments.bhobba said:Observations in QM exists independent of brains except for some very fringe interpretations of QM .
Why people want go down brains, conciousness etc being involved has me beat. It leads to an unnecessarily weird view of the world.
Thanks
Bill
Bruno81 said:That 'weird' view of the world is a non-Newtonian worldview. The Newtonian worldview is dead wrong and a worldview of the 18 century.
bhobba said:Causal - one thing causing another. Initial conditions cause final conditions.
I think you need to learn what superposition in QM is. Its got nothing to do, except perhaps very indirectly, with causality or determinism, it simply expresses the vector space structure of pure states.
That's not what a formula is nor is it how math works, or rather it would be a very unusual view of logic - most would not classify consequences from the rules of logic as constraints. You might like to become acquainted with, for example, Topos theory.
Thanks
Bill
Its a fact that two waves can add, which have a result. the result can, in principle. be retraced to their cause. The result is a superposition.bhobba said:Causal - one thing causing another. Initial conditions cause final conditions.
I think you need to learn what superposition in QM is. Its got nothing to do, except perhaps very indirectly, with causality or determinism, it simply expresses the vector space structure of pure states.
That's not what a formula is nor is it how math works, or rather it would be a very unusual view of logic - most would not classify consequences from the rules of logic as constraints. You might like to become acquainted with, for example, Topos theory.
Thanks
Bill
Please read again, it's in English:bhobba said:That's incorrect. The modern non Newtonian world view has nothing to do with conciousness, brains etc etc except in very fringe interpretations
Bill
You should stop spreading misinformation. The Newtonian universe is a misconception of the past and no, it is not a matter of taste. It can't be something else and Newtonian(just in spirit) because it's not Newtonian. The Newtonian universe would have been true if the universe was made of solid balls of matter as Newton envisioned and the speed of light wasn't constant across frames of reference(among many other things). Please read and follow the rules to which you agreed upon signing up. But this is all offtopic and if you like to argue for a Newtonian universe, just start a separate thread.Beyond that there are interpretations of both QM and even relativity that are Newtonian in spirit.
Bruno81 said:You should stop spreading misinformation. The Newtonian universe is a misconception of the past and no, it is not a matter of taste.
Edward Hunia said:Thats determinism. I think things can be causal, which we should understand as constraints, yet be non deterministic
Edward Hunia said:Its a fact that two waves can add, which have a result. the result can, in principle. be retraced to their cause. The result is a superposition.
Edward Hunia said:I disagree, one can indeed look at math as a simply constraint... and do well that approach.
Isn't determinism only a forward-in-time causality? That is, given the state of the system at t, its state at t+dt can in principle be 'calculated' (determined)?bhobba said:That makes no sense.
A differential equation from its initial conditions uniquely determines what happens at any time t - that's from the theory of differential equations. That's pretty much the definition of cause.
entropy1 said:IWe get causal loops. Is the (total) system state still calculable?
I don't understand this, but that is my problem. Don't bother.bhobba said:That makes no sense at all - at least as far as I can see. Differential equations in general aren't reversible because you have phenomena like strange attractors when different starting values wind up in the same place. But even if it was there is no loops involved.
T%hanks
Bill
entropy1 said:I don't understand this, but that is my bad. Don't bother.
That is a good question. Adopting a no realism/epistemic interpretation does appear to avoid ontic, non-local causal influences (and maintain a fully relativistic account of physical goings-on). But, at the same time, it's not clear that a non-realist interpretation actually saves locality because in adopting that kind of interpretation, the distinction between 'local' and 'non-local' would not even appear to apply.entropy1 said:So, if there is no realism, a particle may not even exist if not measured? What does the qualification 'local' mean in this context?
Thank you. It seems to me that, if you don't measure the event, there is at least no 'informational' connection established between the observer and the event - concerning a measurement. (?)bohm2 said:That is a good question. Adopting a no realism/epistemic interpretation does appear to avoid ontic, non-local causal influences (and maintain a fully relativistic account of physical goings-on). But, at the same time, it's not clear that a non-realist interpretation actually saves locality because in adopting that kind of interpretation, the distinction between 'local' and 'non-local' would not even appear to apply.