Entanglement Could Be a Deterministic Phenomenon 259
KentuckyFC writes "Nobel prize-winning physicist Gerard 't Hooft has joined the likes of computer scientists Stephen Wolfram and Ed Fredkin in claiming that the universe can be accurately modeled by cellular automata. The novel aspect of 't Hooft's model is that it allows quantum mechanics and, in particular, the spooky action at a distance known as entanglement to be deterministic. The idea that quantum mechanics is fundamentally deterministic is known as hidden variable theory but has been widely discounted by physicists because numerous experiments have shown its predictions to be wrong. But 't Hooft says his cellular automaton model is a new class of hidden variable theory that falls outside the remit of previous tests. However, he readily admits that the new model has serious shortcomings — it lacks some of the basic symmetries that our universe enjoys, such as rotational symmetry. However, 't Hooft adds that he is working on modifications that will make the model more realistic (abstract)."
I knew it. (Score:5, Funny)
Free will is a sham. Of course, believe whatever you will. It's not like you have a choice.
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Re:I knew it. (Score:4, Insightful)
I choose NOT to make a choice!
Rush [lyricsfreak.com] thanks you for making your choice.
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Lyrics as written in the album pull-out: "if you choose not to decide you cannot have made a choice".
Lyrics as sung: "if you choose not to decide you still have made a choice".
So they're agnostic on what it means to be agnostic - I refuse to believe this was a printing mistake, it's just too clever.
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This is covered in the Rush FAQ [nimitz.net] - evidently it was printed correctly in Canada, which is why whenever some American told them it was wrong, they replied "no it isn't, eh."
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I choose NOT to make a choice!
That seems foolish to me.
- If you have free will and do your best to exercise it in your own interest, you have a chance to exert some control over your situation and benefit yourself.
- If you have free will and do not do your best to exercise it in your own interest, you are likely to do poorly.
- If you don't have free will it doesn't matter.
So the best path seems to be to assume you have free will and act accordingly.
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Re:I knew it. (Score:5, Insightful)
Free will is a sham. Of course, believe whatever you will. It's not like you have a choice.
Dude, if you were counting on the non-determinism of quantum entanglement to save the concept of free will, then you were out on a limb to begin with. How is randomly following the rules of the universe any more a matter of "will" than deterministically following them?
You could try to rely on a seriously weird and unlikely interpretation of QM which is basically a pun (measurement -> observation -> observer -> sentient observer), but then you're using the concept of sentience/free will influencing quantum events to explain how sentience/free will is possible in the first place. Maybe it's possible, but it's quite a long shot to be basing your whole concept of self awareness on.
I have free will because as far as I can tell I exercise it. In a pure philosophical sense you could never prove you have it even if we somehow did show that QM is influenced by "observers". But that act of faith has worked well enough for me. I'm certainly going to live my life as though I have free will, and if I'm only "automatically" making that choice, then so be it.
Its just a matter of modeling (Score:5, Insightful)
When you model the universe in terms of will-less mechanisms, you will (amazing!) discover that free will is a logical impossibility.
Trying to model free will in terms of physics is like trying to describe the combustion engine using only the words found in a book on home gardening.
The only reason some people find this personally problematic is because they have decided that our current model of physics is also the concrete, accurately-represented holy truth. In fact, our current model is just an abstract representation of something we can't see, and it is just the best we've come up with so far (in fact, any scientist worth his salt will predict that our models will change in the future).
So the quantum-mechanical model of the universe is incompatible with any free-will-is-real model of the universe. So what? This incompatibility doesn't make either theory right or wrong. The evidence for each theory is all that matters.
As Epicurus [wikipedia.org] (one of the fathers of the modern scientific method) advised, "if several theories are consistent with the observed data, retain them all."
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And how would you model the universe.. In terms of magic?
Ask an alchemist. (Score:4, Insightful)
Or maybe a Sorceror.
Or maybe a Christian.
Modeling the universe in terms of magic is what humanity has been doing for most of recorded history.
Modeling the universe in terms of mechanical interactions of particles or waves is the new-and-cool. And we are still getting our heads around how to do it.
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Why not? Belief systems still function even though we don't understand why or how they work. For most of the population, quantum physics might as well be magic!
I have a particular opinion about which is a better model, but I'm an admittedly lousy "magical thinker." ;^)
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Toro
Any model will do (Score:2, Insightful)
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And how would you model the universe.. In terms of magic?
That question seems to miss the point. The word "truth" means something different in science. Science seeks to answer the question "what is a useful and predictive model of how the universe works", and often calls that concept "truth". Science is just not involved with the question of "OK, that's a model, but how do things really work?". Scientists are of course as interested in that philosophical question as anyone else, but "how do things really work?" is a question of philosophy, not science.
If the b
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Threshold is a good working concept when addressing how to model a complex thing. In science threshold can be ostensibly seen in terms of the first microscope and the first telescope. From there spectroscopy presents another method with certain thresholds. Studying sound to model the inner sun is a recent example to getting around limitations to extend our present thresholds enabling and constraining our ability to model the Universe. The fact that we've hypotheses like String Theory suggests there are thre
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The current model of the universe is not necessarily composed of will-less mechanisms.
In fact the non-determinism of QM (if it is so) could be exactly the mechanism by which free will is introduced into the universe. QM does not have to be random as insinuated by the GP, but it instead could be the method by which free will forces (perhaps our 'souls') outside the universe (as we see it) inject their free will into the universe (by slight manipulation of the odds so to speak).
I don't believe this myself, b
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I've never seen a definition of "free will" that would be empirically testable. Actually, I don't think I've ever seen a definition of fre
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My own definition of free will, from the philosophical side, is the same as "conscious choice". Free will reduces to the question of sentience or self-awareness (or actually a precondition for that), which is not itself well-defined but is still interesting. Basically, if you think you have free will, you can't be wrong, any more than if you think you're in pain you can be wrong. It's empirical, but only as a concious state, just like pain.
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I can accept that sort of definition as somewhat reasonably, but that seems to remove it entirely from the realm of metaphysical arguments people like to have about free will.
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No, you don't. Newton's clockwork universe is certainly composed of "will-less mechanisms" yet once you investigate closely you notice that there are nooks and crannies where unpredictability hides, allowing for things like free will. Likewise, the standard interpretation of quantum mechanics doesn't have any "and here there be willful bits" in it, yet quantum uncertainty and randomness leaves the door open for free will. Most hidden variable QM interpretations, likely including this one, also leave room
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The thing is, I don't see it just as a matter of existing models being incompatible free will. I don't see how any model of the universe, whether deterministic or probabilistic, supports the idea of free will.
So I can certainly see your point that the current model may be wrong, and that we may simply not be using the right language to describe the universe, but my question is, how do you introduce that language to expand the models that can be expressed to include those that allow free will? And don't ju
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I have free will because as far as I can tell I exercise it.
Free from what? That's the real question.
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Interesting subject.
Or maybe just pointing out that there's room for free will in the quantum model. I know the idea is unpopular among physicists, but I didn't think anything had emer
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Or maybe just pointing out that there's room for free will in the quantum model. I know the idea is unpopular among physicists, but I didn't think anything had emerged that made it significantly less likely than any other interpretation.
I don't like the idea of taking some poorly understood part of the universe, speculating that "consciousness" might be involved because it isn't explicitly excluded by current understanding, and saying that's where free will lies. It sounds like wishful thinking to me, or a
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Or, put another way, you are not capable of perceiving the phenomena that constitute your deterministic behavior ahead of time. This should come as no surprise, since doing so would no doubt interact with that very behavior. Not to mention that we're all caught up in a Sensitive Dependence On Initial Conditions maelstrom on every level imaginable.
I have free will (Score:2, Funny)
...because I choose to believe that I have free will.
If you don't believe in free will, then there's no use arguing with me, because it's been pre-determined that I will believe in free will.
PS:
Isn't trying to change someone's mind pretty much a futile gesture to a determinist?
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I am a determinist because I believe that everything that ever happened and everything that ever will happen can be explained by particles following one simple rule: The path of least resistance.
The fact is that in following that path, my brain insists on convincing you of my wisdom. It may very well be that in following that path, your brain begins to believe that I am in fact extremely wise.
That this is inevitable, I cannot say.
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And the path of least resistance is inevitably entropy. The abyss called, it wants to stare back at you.
Scary to consider, but I think you're dead on.
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Toro
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It may be, but science has not even attempted to define who I, my conscious self, am.
How does a lump of grey matter result in a singular consciousness?
All you other fuckers, you're just deterministic machines. I could model you perfectly given enough time.
But me? I'm something...else.
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Well, will is nothing more than the output of a huge amount of data fed into a chaotic function.
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You could try the definition of "free will" that Larry Niven used in "Protector":
Free will is the result of not being able to accurately predict the best action.
That's a paraphrase, but I think I preserved all the meaning without dragging in a lot of story context. If you know what the best action is, then you will follow that course of action. So you don't have free will. If you don't know, and you don't know enough about yourself to accurately model why you are making the decision that you are making,
Re:I knew it. P.S. (Score:2)
There are theoretical arguments that imply that it's impossible to accurately model why you are making your decisions at any great level of detail. They're rather convincing, but not totally so, especially when I slip in the constraint "at any great level of detail" rather than claiming perfection in the modeling.
But they're still rather convincing. And then there's the time element. By the time you've finished your modeling, the decision is likely to be long past.
So free will is a good working approxima
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That's where the philosophy chokes. It assumes making a decision, i.e. weighing pros and cons and your emotions and information, is somehow magically free of both determinism and random control. They may have influence, but ultimately there's some mysterious spiritual thing beyond determinism and randomness that's doing the deciding in a manner that doesn't involve either.
Which, I submit, makes no sense. Weighing options is the essence of determinism, for that matter.
More importantly, back to the physics
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you can easily base quantum on determinism if you give up on Einstein's concept of reality. Which is to say, that there are "real things out there with real, measurable properties".
Quantum implies heavily that, for example, there is no particle out there with an actual, measurable position, and so on.
You needn't give up on Einstein's notion just to believe in QM. There are still real things out there, with real, measurable, probabilistic properties. There's nothing more 'real' about a Bohr atom than a Planc
Re:I knew it. (Score:4, Insightful)
> But if Quantum Mechanics itself was, say, a computer simulation... ...then the computer on which the simulation is running must exist in a universe. You now have replaced a few hidden variables with an entire hidden universe. Apply Occam's Razor.
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In fact, I'd say that Occam's Razor is a tautology. What it really says is that a simpler solution/explanation is more easily implemented/grasped. More useful and productive.
No matter how complex things actually are, it's nothing but art appreciation if you can't wrap your head around the idea, understand, and produce something with that understanding.
That is the essence of Occam's Razor.
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Toro
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Poor Occam. Mistranslated, misinterpreted, and probably misattributed.
I agree with you, and perhaps you misunderstood me.
I parse the original with a context of: "Do not multiply entities needlessly, because you will rapidly exceed your own faculties. It's a limited resource. Make it count."
This translates to "simple solutions are more productive because they are more readily understood and implemented." It's an engineering application, rather than theoretical.
Corollary to Occam's Razor: Increased complexity
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It is even more clear the other way around (and more accurate, as another poster pointed out). Occam's razor says that there is nothing to be gained by adding bits to a theory that don't make it work any better.
The general principle of Occam's razor is often used another way though: if a theory becomes very complicated, full of special cases and exceptions, we are suspicious of it's underlying principles, even if it is the best match to the observations.
A geocentric solar system with epicycles fits observa
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Yup. What's up with string theory? ;^)
Toro's Razor: Fundamentally useless but appealing information is art.
--
Toro
(See my other post upthread, this is a very cool discussion. Thanks.)
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String theory has a very attractive (and very simple) basic idea - that fundamental particles are not dimensionless points, but rather extended objects with one or more dimensions. The problems come when you try to figure out what that means. The whole thing gets really complicated, really fast.
The idea behind string theory is actually that, given a very simple starting point (the existence of very small strings that vibrate, plus some other properties), everything else follows. Most of the complication
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PS: Cellular automata are in many ways very similar to string theory. The idea is that by starting with something very simple, you can get very complicated behaviour. The problem is, there aren't any proper mathematical tools for predicting that behaviour, except in very simple cases. The best you can do it try it out and see.
Take Conway's game of life, for example. Given a non-trivial starting arrangement, without actually running through all the iterations, can you predict the state the system will st
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But if Quantum Mechanics itself was, say, a computer simulation... ...then the computer on which the simulation is running must exist in a universe.
Not necessarily. The computer on which the simulation is running may be the universe. A very simple one perhaps, but capable of running itself as well as any number of simulations.
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It assumes making a decision, i.e. weighing pros and cons and your emotions and information, is somehow magically free of both determinism and random control. They may have influence, but ultimately there's some mysterious spiritual thing beyond determinism and randomness that's doing the deciding in a manner that doesn't involve either.
Where does this nonsense come from? If you did something and feel later that there is some mysterious spiritual thing that decided what that something was, seek help before the mysterious spiritual thing has you jumping off a roof. I think using the word 'free' to describe something is a disservice to everyone who follows. Like FOSS, the free in free will is a distraction that will never go away. Is it controversial to say that someone has 'will power'? Why is it a controversy for intelligent animal
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The Honking.
(Sigh.)
Hidden controlled by Hidden (Score:4, Insightful)
I've often been skeptical of the idea that you could disproove a hidden variable. The hidden variable itself could be dynamic controlled by another hidden variable.
I guess I just assume that there is more we don't know about the universe that we do know about it.
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> The hidden variable itself could be dynamic controlled by another hidden variable.
You can't fool me, young man! It's variables ALL the way down! :)
Re:Hidden controlled by Hidden (Score:5, Informative)
It's not really valid, though; it makes a false distinction between "a hidden variable" and "a hidden variable controlled by another hidden variable" as if they were different. Bell's theorem covers (or at least appears to cover) any additional information or state, regardless of the theory or process involved, provided that state is "attached" to the entangled particles (that is, it's local).
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provided that state is "attached" to the entangled particles (that is, it's local).
A hidden variable:
return self.state;
A hidden variable controlled by another hidden variable:
self.state = self.last_observed_by->state;
return self.state;
An entangled variable that isn't known yet:
self.state = calc_state(self, self.last_observed_by);
return self.state;
I think these three are very different cases, and afaik (not much) only the first has been ruled out. Just because the second and th
Re:Hidden controlled by Hidden (Score:4, Informative)
Bells inequality rules out every possibility of the case:
result_of_experiment = me.some_function();
where some_function() has access to the entire history of me plus as much additional local information as you like (including internal variables) and it is deterministic.
There is a tiny "loophole" in that a truly rigourous test is extremely hard to do and not everybody agrees that the experiments done so far are 100% watertight.
Tim.
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It's not really valid, though; it makes a false distinction between "a hidden variable" and "a hidden variable controlled by another hidden variable" as if they were different.
I can't remember who said this (might have been Hawking or Sir Francis Bacon) was that there is a very important difference between "That which 'I know I don't know' and that which 'I don't know that I don't know'"
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I'm not entirely sure how you intend that to be applied to this topic, but it's certainly true. To use Rumsfeld's terms, unknown unknowns are completely different from known unknowns.
His model is all wrong (Score:2, Funny)
In his model of the universe, everyone has a beard or goatee.
Come up with a generic theory... (Score:2)
And then tweak it to match reality.
I'm afraid people do that all the time, each one new and different.
But why do they bother? We already have the ultimate "parameterize and tweak the theory to match reality" theory in String Theory, so why bother with anything else?
Re:Come up with a generic theory... (Score:4, Insightful)
Come up with a generic theory...And then tweak it to match reality.
I'm afraid people do that all the time, each one new and different.
Uh...yeah. That is how the scientific process is supposed to work. You form a hypothesis based on what you know already, you test it, and as the results of your tests roll in, you modify the hypothesis accordingly. Form and then tweak. This is the essence of all scientific progress we have made to date.
Why do you have a problem with this? I'd say the proof is in the pudding.
But why do they bother? We already have the ultimate "parameterize and tweak the theory to match reality" theory in String Theory, so why bother with anything else?
Because string theory lacks evidence, and we don't have the technological means to gather much evidence for it (at present). Also, at present, the theory fails to offer much utility (we can't build any useful devices based on string theory).
Your attitude sounds a bit scarey. I read it as, "we already KNOW the truth, so why continue looking?" This very attitude inhibited scientific progress for most of human history. I wonder if it also inhibits you?
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This argument only seems relevant if your generic theory is completely generic; that is, with the proper choice of parameters, it can be exactly equal to any alternative theory. This is true neither of string theory nor physics-as-cellular-automata.
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Things that in happening, cause themselves to happen again, happen again.
Whoa. (Score:2)
Well that's a relief. I thought everything was my fault.
"Backwards" Causation (Score:5, Interesting)
Bell's inequalities fall apart if current particles can "know" about future measuring devices. However, for particle physics, neither direction of time is privileged. Particles are just as likely to be influenced by future interactions as they are by past interactions. Because of this, there is no "action at a distance". Influences travel along the backwards light cone and remain perfectly relativistic.
This simple, straightforward solution has been largely ignored.
Note that most interpretations of quantum mechanics are explicitly time asymmetric due to the "collapse" caused by observation. Cramer's transactional theory is an exception, it is symmetric and there is no collapse, but it doesn't get much attention.
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Exactly, it seems that most quantum mechanicists assume that the fundamental equations must be hyperbolic in nature. However, general relativity admits solutions with closed time-like curves. This means that a theory combining quantum mechanics and general relativity must as well. (Since in the classical limit it must reduce to general relativity.) Closed time-like curves mean that forward-evolving your hyperbolic equations of motion is impossible. In effect, the loops in time cause future boundary con
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Einstein's Law of Causality states pretty clearly that Time is Uni-driectional, and you'd have to present a pretty solid proof to disprove the Law of Causality. People have tried but short of building a time machine I'm pretty sure the Law of Causality isn't about to fall just yet.
Re:"Backwards" Causation (Score:4, Informative)
Particles are just as likely to be influenced by future interactions as they are by past interactions
This seems to be a poor understanding of time reversal symmetry. Particle physics works if you run time forward, or if you flip its sign and run time backwards. But that does not mean the same thing as what you said above. You can look at an experiment with each event in reverse, but you can't, for instance, say that event 2 was caused by event 1, but event 1 was caused by event 3. It only can follow the laws of physics if the causal order is 123 or 321.
The idea of 'backwards' causation has obvious major problems. First of all, you run into causal paradoxes. But more importantly, if the outcome of your experiment rests on future events, how can you do science? Every result becomes meaningless because you don't know if a future event caused it.
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This act of preventing a future event is known as "bilking" and is a pretty sound argument against time travel. However, bilking is impossible for entangled particles.
I'm talking about backwards causation as a general principle.
On macroscopic scales not much changes since backward causes are limited...
Says who? What is the definitive study of backwards causation? I'd like to see some sources which claim that violating causality would not cause experimental problems. What about simple particle physics experiments where we are working on microscopic scales?
Moreover, sometimes science and mathematical calculations are hard. But that's the way the world is and the simplicity of calculations can't stand against the reality of observations. Calculation difficulties have been around since the three body problem.
You're not understanding my point. I didn't say the calculations or experiments would be difficult. I said that in any experiment where future events would have to be taken into account, you co
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On macroscopic scales not much changes since backward causes are limited...
Says who? What is the definitive study of backwards causation? I'd like to see some sources which claim that violating causality would not cause experimental problems. What about simple particle physics experiments where we are working on microscopic scales?
Without an entropy gradient from past to future we would be in heat death. The only bodies of knowledge that have any relevance in heat death are particle physics and perhaps some chemistry. Anything that depends on the entropy gradient for its existence, such as all biological creatures, will be strongly asymmetric in time. Thus, animals die after being born and not vice versa. What I'm saying is that backwards influences will exist, but they will be incredibly overpowered by the asymmetry of the entropy g
not much of a theory (Score:2)
Cramer's transactional theory is an exception, it is symmetric and there is no collapse, but it doesn't get much attention.
As far as I know, Cramer's "theory" doesn't make any testable predictions. Hence, it's not actually a theory, it's more like religion or philosophy.
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Isn't Bohmian Mechanics a perfectly solid hidden variable theory that handles this?
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If "causality" as you use it is explicitly asymmetric, then yes, it's fairly straightforward to reject it. Typical arguments against backwards causation don't apply to these quantum measurements. Why? Because it's impossible to get between the particle and the future measurement. Any attempt to do so just becomes a measurement in itself. "Causality" as described by Bell just seems like simplistic philosophy. The very inequalities Bell derived should serve as a counterexample to this notion of "causality".
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Given that Bell's inequality has been violated routinely
Aren't there laws against that?
Spin on it (Score:2)
The phrase "spin on it" clearly means different things to different physicists but not having rotational symmetry sounds like more than just a big flaw it sounds like the sort of flaw that you really should try and fix before saying that you've just proved huge numbers of physicists wrong.
Its a mind-bending idea to model the universe in this way and personally I think it will fail because of H2G2
"Some people believe that if man understands the universe then it will be automatically replaced by one even more
Dammit, there goes the planet. (Score:5, Funny)
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Actually if Stephen Wolfram turns out to be correct then his ego must be defined by Rule 110 [wolfram.com] which, as has already been proven, is universal; it expands forever and is full of hot gasses.
How does "no hidden variable" not apply? (Score:2)
If anybody here can give a short explanation on how this gets around these proofs, I would be grateful. I remember being pretty convonced by the proof and did not see a way around it. Although, personally, I believe that hidden variable fits reality better, as entanglement with non-determinism needs an extension of the model of the Universe, while "hidden variable" can get by without. Being a CS, I prefer simpler solutions any time ;-)
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It allows non-local influences. The hidden variable proof assumes a local universe.
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See my response below - it has to be either non-local, non-causal or exceed the speed of light. (These are of course coupled possibilities.) If he has found another way around Bell's Theorem, I bet he would be touting that, not cellular automata.
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Hmm, yes, I think that would do it. Thanks.
Seems to me that the Quantum-Theory people know a lot less at this time than some of them pretend to.
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Not exactly. These are all different interpretations of quantum theory. The interpretation most people think IS quantum mechanics is called the Copenhagen interpretation. There have been others right from the beginning. They all use the same equations and produce the same results, but the story that goes along with them is different.
Hilbert Space (Score:2)
The invocation of Hilbert space in the article suggests a LINEAR cellular automata. It would suggest the possibility of any two points in space affecting each other through a very long, but singular line. The concept is akin, if I understand it correctly, to saying that the entire universe is one long line in Hilbert space and thus each iteration of movement affects all others.
but, IANAP
A Nonlocal Hidden Variables Theory? (Score:4, Informative)
Firstly, I find the title of the submission a little odd. I mean, Entanglement can easily be understood as "deterministic" in a sense in conventional quantum mechanics. The generation of entanglement via the Schroedinger equation is quite deterministic. What's usually understood as non-deterministic is what happens when you measure.
I saw a talk by t'Hooft a number of years ago (I actually had lunch with him and my adviser). He was talking about a similar idea then, and my interpretation was that it evaded Bell's Theorem by being a non-local hidden variables theory. I haven't read the paper, so I'm not certain if this new idea is significantly different.
For background: Bell's Theorem is a result that shows that a local realistic hidden variables theory (a theory where each, say, particle has some hidden degree of freedom that determines the outcome of a measurement on it before the measurement is made) cannot reproduce the results of quantum mechanics for an entangled quantum state. To get around this obstacle, it's generally said that you either have to give up determinism (things don't have one specific state, etc. , before they're measured) or locality (the outcome of an experiment in one place may be totally changed by events happening at the same time arbitrarily far away)
Hidden variables and metaphysics (Score:2)
As I understand it, there are hidden variable theories completely in sync with experiment. But they are experimentally indistinguishable from true randomness - and hence serve no scientific purpose (although answering Einstein's famous objection, "God does not play dice"). A hidden variable theory where the "hidden" variables can be deduced by experiment "inside" the universe is no longer a truly "hidden" variable theory.
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"Hidden" in this sense doesn't mean "impossible to deduce by experiment" but simply "currently unknown to us".
3 choices (Score:5, Informative)
Hidden variables in this case should be thought of as a hidden micro-states. A hidden variable theory would have quantum mechanics be something like thermodynamics; i.e., a theory that is not really basic, but appears so as we cannot see the fine scale true reality. Einstein was convinced that this had to be the case.
The tests of Bell's Theorem shows that no locally causal hidden variable theory is viable. This says basically that one of these must be the case
There are no hidden variables (i.e., true quantum uncertainty applies, and quantum mechanics is correct).
The speed of Light can be violated (i.e., there are hidden states that can exchange information faster than the speed of light). This implies, by the way, causality failures would be possible, so that in principle you could do something like kill your grandfather and prevent your own existence.
There is action at a distance (i.e., the theory is non-local).
There has long been a viable theory, that of Bohm [wikipedia.org], that replicates normal quantum mechanics. It's non-local.
I cannot tell from a read of the article (and without seeing the underlying paper) if 't Hoof has a non-local theory or just how he stays consistent with Bell's Theorem.
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The tests of Bell's Theorem shows that no locally causal hidden variable theory is viable. This says basically that one of these must be the case
There are no hidden variables (i.e., true quantum uncertainty applies, and quantum mechanics is correct).
The speed of Light can be violated (i.e., there are hidden states that can exchange information faster than the speed of light). This implies, by the way, causality failures would be possible, so that in principle you could do something like kill your grandfather and prevent your own existence.
There is action at a distance (i.e., the theory is non-local).
Or, since we're talking about quantum states, it could be that any combination of the three and not the three are the case, only to collapse to one (or more) of them when you make your observation.
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The speed of Light can be violated (i.e., there are hidden states that can exchange information faster than the speed of light). This implies, by the way, causality failures would be possible, so that in principle you could do something like kill your grandfather and prevent your own existence.
Not necessarily. One possible alternative is the Novikov Self-Consistency principle [wikipedia.org], which posits that if a faster-than-light communication or a classical 'time travel' ever did occur, the probability of those events
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Yes, and I have to wonder if that sort of self-cancelation could be built into a cellular autonoma model. That would be interesting.
I recently read Alastair Reynolds House of Suns [amazon.com], and this deals with causality violations, by name. I don't think his solution would work as physics, but it's not impossible, and I thought it was very cool that he recognized and described the issue.
Konrad Zuse? (Score:2, Insightful)
Well, duh.... (Score:2)
anyone who's ever tried to wind up power cords or ethernet cables knows that.
Re: Well, duh.... (Score:2)
anyone who's ever tried to wind up power cords
Like this [electric-g...s-rock.com]?
Facinating news for the mathematical universe (Score:2)
We are describing the universe with mathematics. Mathematics are wholly invented by man. The rules are deterministic. Where we get unexpected results, such as with chaos mathematics, all we can do is map the boundaries and boggle.
Eventually, when you do enough math, everything you can understand about the universe with math alone is going to look deterministic because of the semantic properties of the language you are using to describe it.
So the question is, what are we leaving out by boiling the universe d
Autoverse in Greg Egan's Permutation City (1994) (Score:2)
Sounds like the Autoverse in Greg Egan's novel "Permutation City".
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The kicker is that, according to quantum mechanics which t'Hooft is attempting to dispute (I think), some of your numbers will be probabilities. So it isn't like you could predict the position and velocity of an electron. And even the probabilities might not conform to a logic system you would use, they might conform to a quantum logic. So reasoning from your automata might not be entirely straightforward.
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I'll believe it when it's finished downloading - I may be some time.
I'm afraid you'll be disappointed. You wanted Universe-src.tar.bz2. You're currently downloading a compiled binary.