Determinism (also called antiserendipity) is the philosophical proposition that every event, including human cognition and behavior, decision and action, is causally determined by an unbroken chain of prior occurrences.[1] With numerous historical debates, many varieties and philosophical positions on the subject of determinism exist from traditions throughout the world.
Determinism, quantum mechanics and classical physics
Some people have argued that in addition to the conditions humans can observe and the rules they can deduce there are hidden factors or hidden variables that determine absolutely in which order electrons reach the screen. They argue that the course of the universe is absolutely determined, but that humans are screened from knowledge of the determinative factors. So, they say, it only appears that things proceed in a merely probabilistically determinative way. Actually, they proceed in an absolutely determinative way. Although matters are still subject to some measure of dispute, quantum mechanics makes statistical predictions that would be violated if some local hidden variables existed. There have been a number of experiments to verify those predictions, and so far they do not appear to be violated although many physicists believe better experiments are needed to conclusively settle the question. (See Bell test experiments.) It is, however, possible to augment quantum mechanics with non-local hidden variables to achieve a deterministic theory that is in agreement with experiment. An example is the Bohm interpretation of quantum mechanics.
So quantum mechanics is deterministic, provided that one accepts the wave function itself as reality (rather than as probability of classical coordinates). Since we have no practical way of knowing the exact magnitudes, and especially the phases, in a full quantum mechanical description of the causes of an observable event, this turns out to be philosophically similar to the "hidden variable" doctrine.
Libertarianism (metaphysics)
Libertarianism is a philosophical position in metaphysics with respect to free will and determinism. It entails the belief that human beings possess free will, that free will is incompatible with determinism, and that determinism is false.
Although not held by the majority of contemporary philosophers, libertarianism is still widely discussed and avidly defended by several leading philosophers in the field, such as Peter van Inwagen, Robert Kane, Timothy O'Connor and Laura Ekstrom.
Natural libertarianism
Naturalistic libertarians believe that the universe contains an indeterminstic element, for instance as demonstrated by quantum mechanics, and that human beings exploit this to achieve freedom of choice. There is no separate, dualistic self in this theory: the self is the total activity of the brain as a system.
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Indeterminism
At one time, it was assumed in the physical sciences that if the behavior observed in a system cannot be predicted, the problem is due to lack of fine-grained information, so that a sufficiently detailed investigation would eventually result in a deterministic theory ("If you knew exactly all the forces acting on the dice, you would be able to predict which number comes up"). However, the advent of quantum mechanics removed the underpinning from that approach, with the claim that (at least according to the Copenhagen interpretation) the most basic constituents of matter behave indeterministically, in accordance with such properties as the uncertainty principle. Quantum indeterminism was controversial on its introduction, with Einstein among the opposition, but gradually gained ground. Experiments confirmed the correctness of quantum mechanics, with a test of the Bell's theorem by Alain Aspect being particularly important because it showed that determinism and locality cannot both be true. Bohmian quantum mechanics remains the main attempt to preserve determinism (albeit at the expense of locality).
Bohm interpretation
The Bohm interpretation of quantum mechanics, sometimes called Bohmian mechanics, the ontological interpretation, or the causal interpretation, is an interpretation postulated by David Bohm in 1952 as an extension of Louis de Broglie's pilot-wave theory of 1927 . Consequently it is sometimes called the de Broglie-Bohm theory. Bohm's interpretation is an example of a hidden variables theory. It is hoped that the hidden variables would provide a local deterministic objective description that would resolve or eliminate many of the paradoxes of quantum mechanics, such as Schrödinger's cat, the measurement problem, the collapse of the wavefunction, and similar concerns. However, Bell's inequality complicates this hope, as it demonstrates that there is no local hidden variable theory that is compatible with quantum mechanics. Thus, one is left with choosing between the lesser of two evils: discarding locality, or discarding realism. The Bohmian interpretation opts for keeping realism and accepting nonlocality.
Nonlocality
Others see the consequences of EPR and Bell's theorem in a different way. They regard the correct conclusion to be related not so much to quantum theory itself, but only to deterministic interpretations of the same (i.e., to hidden-variable theories such as Bohm's interpretation). According to the people who think this way, what has been shown is that all deterministic theories must be nonlocal. For example, Niels Bohr was a member of this group. This group would claim that retaining orthodox quantum mechanics — with its nondeterministic character — permits one to retain locality, or at least to avoid the EPR type of nonlocality, at the expense of having no way to picture particles as objective elements of reality that occupy definite regions of space at all times. Armed with such a viewpoint, these physicists tend to be less receptive to Bohm's interpretation.
Seen as isomorphic to many worlds
Explicitly non-local. Bohm accepts that all the branches of the universal wavefunction exist. Like Everett, Bohm held that the wavefunction is real complex-valued field which never collapses. In addition Bohm postulated that there were particles that move under the influence of a non-local "quantum- potential" derived from the wavefunction (in addition to the classical potentials which are already incorporated into the structure of the wavefunction). The action of the quantum- potential is such that the particles are affected by only one of the branches of the wavefunction. (Bohm derives what is essentially a decoherence argument to show this, see section 7,#I [B]).
The implicit, unstated assumption made by Bohm is that only the single branch of wavefunction associated with particles can contain self-aware observers, whereas Everett makes no such assumption. Most of Bohm's adherents do not seem to understand (or even be aware of) Everett's criticism, section VI [1], that the hidden- variable particles are not observable since the wavefunction alone is sufficient to account for all observations and hence a model of reality. The hidden variable particles can be discarded, along with the guiding quantum-potential, yielding a theory isomorphic to many-worlds, without affecting any experimental results.
—Michael Clive Price
See Also:
Hi Plato,
ReplyDeleteI see you have moved further on to the subject of the foundations. I think you are aware that this aspect of current understanding holds great interest for me. You certainly have peaked my interest when you point to Bohm, deterministic theories and the viability therein. I must however insist that what is written here is not simply inaccurate yet rather false. I could take some time and pick things apart a point at a time and explain all the reasons I know this to be. Yet in as it has taken me somewhat more then ten years to come to this firm position, you can appreciate that would take some time.
I believe therefore it is better to let those involved do the speaking for themselves. First what you’ve written would leave the reader the impression that Bell’s purpose in discovering his inequality was to have upon experimental confirmation later be able to support and reinforce the standard QM interpretations and discredit all so called “hidden variables” approaches, including Bohm’s pilot wave interpretation. Here I submit some of what he said in this regard in a paper he wrote entitled [On the impossible pilot wave-Foundation of Physics 12(1982) 989-999]:
“When I was a student I had much difficulty with Quantum Mechanics. It was comforting to find that even Einstein had such difficulties for a long time. Indeed they lead him to the heretical conclusion that something was wrong with the theory: ‘Indeed I am in fact firmly convinced that essentially the statistical nature of contemporary quantum theory is to be solely ascribed to the fact that this (theory) operates with an incomplete description of physical reality.’………………………………Einstein did not seem to know that this possibility had been disposed of with great vigor by J.von Neumann. I myself did not now von Neumann’s demonstration at first hand………………….Having read this I relegated it to the back of my mind and got on with more practical things.”
“But in 1952 I saw the impossible done. It was a paper by David Bohm showing explicitly how parameters could be indeed be introduced, into non relativistic wave mechanics, with the help of which the indeterministic description could be transformed into a deterministic one. Most importantly in my opinion , the subjectivity of the orthodox version, the necessary reference to the ‘observer’ could be eliminated.”
“Why is the pilot wave picture ignored in textbooks? Should it not be taught, not as the only way, but as a antidote to the prevailing complacency? To show that vagueness, subjectivity, and indeterminism, are not forced on us by experimental facts, but by deliberate theoretical choice.”
“ I will not attempt to answer these questions. But, since the pilot wave picture still needs advertizing, I will make another attempt to publicize it”
As one knows the first of Aspect’s experiments that tested Bell’s inequality was conducted in 1981, a year before Bell wrote the above. Also it should be noted that Bell continued to be a supporter and promotor of Bohmian Mechanic up to his unfortunate and untimely death in 1990. Bell’s position was that the confirmation of his inequality did nothing to disprove or weaken the Bohmian position but rather was more to indicate that if standard QM denied the non local holistic nature that it demonstrates that it then had no link or semblance to reality. This has been reinforced and strengthened since by Bohm himself and others like Prof. Sheldon Goldstein. There are now ongoing attempts to expand this to a full blown field theory of which some headway had been made at PI.
Now this is not to say that this is the last word on all this. However as time progresses the standard way of looking at QM is virtually held by none of the current generation of physicists. It is coming to be realized more and more that rather then Bohm’s model being referred to contain so called “hidden variables” it is more being recognized that orthodox QM has problems, as it has “denied” ones.
This is not to say that I understand that the issue has been decided, yet I have come to understand by way of Einstein’s objections, Bell’s inequality (understood properly) and confirmation thereafter, that it currently to be the firmest and most convincing positio from which to continue to stand and squint to see beyond the shadows. Some of these shadows Bell recognized as being, vagueness, ambiguity, subjectivity yet worse of all complacency.
To conclude, I would say that Bell has continued and expanded on Shakespeare to ask:
‘Beable or not a beable, that is the question?’
Best,
Phil
Perhaps Quantum Gravity can be Handled by thoroughly reconsidering Quantum Mechanics itself?- Gerard t' Hooft
ReplyDeleteHi Phil,
Things are fleeting for me in that what I travelled through to understand entanglement was a slow process for me as well. It would not be without some thinking that Hooft while supporting Lee Smolin's new book, like Penrose, had these same issues about the foundations of Quantum mechanics?
THE MATHEMATICAL BASIS FOR DETERMINISTIC QUANTUM MECHANICS by Gerard ’t Hooft
One now may turn this observation around. A closed system that can only be in a finite number of different states, making transitions at discrete time intervals, would necessarily evolve back into itself after a certain amount of time, thus exhibiting what is called a Poincar´e cycle. If there were no information loss, these Poincar´e cycles would tend to become very long, with a periodicity that would increase exponentially with the size of the system. If there is information loss, for instance in the form of some dissipation effect, a system may eventually end up in Poincar´e cycles with much shorter periodicities. Indeed, time does not have to be discrete in that case, and the physical variables may form a continuum; there could be a finite set of stable orbits such that, regardless the initial configuration, any orbit is attracted toward's one of these stable orbits; they are the limit cycles.
See also: Quantum Mechanics:Determinism at Planck Scale
Then to see Valentini's name through the research and to find the work that is being done, just furthers the "interruption capabilities" that would drive a wedge in between cryptology uses in that same process.
Phil:There are now ongoing attempts to expand this to a full blown field theory of which some headway had been made at PI.
That "same fleetingness" of what I am perceiving lies at the basis of operations at PI could not have been without some influence by some of it's contributors?:)
To see new inventions being developed along the way, as new perceptions and understanding are developed along those same lines as well? There is an advantage there?:)
As I said before, I look forward to you sharing your perceptions about this.
Just come clarification Phil as to whether or not I am following your thought processes?
ReplyDeleteAlso, to summarize what I think PI institute is doing while of course knowing it's diverse agenda.
New Spacetime Quantum World View?
Gerardus t'Hooft
Quantum gravity and black holes . Whenever particles are separated further than 10-33cm, the gravitational force between them is very adequately described by Einstein's theory of general relativity. But when they come closer, the gravitational force becomes strong, whereas gravity is more complicated than gauge theories. Finding a logically coherent theory telling us how particles behave at such small distance scales is a fundamental problem. The most dazzling problem is the question whether these particles will make microscopic black holes. Predicting the behavior of such tiny black holes is a deep theoretical challenge. Or maybe they can't form black holes? Formulating laws of physics that avoid black hole formation is even more difficult. Bold added for emphasis, as to what I think is the methodology of approach at PI?
Hi Plato,
ReplyDeleteIf I agree with Hooft in the detail of his vision, I cannot say, as I have little knowledge of them, yet am intrigued and will look more closely as time permits. Two things I have scanned as to how he thinks I can say I agree with whole heartedly. The first statement found below:
“Theoretical Physics is like a sky scraper. It has solid foundations in elementary mathematics and notions of classical (pre-20th century) physics. Don't think that pre-20th century physics is "irrelevant" since now we have so much more. In those days, the solid foundations were laid of the knowledge that we enjoy now. Don't try to construct your sky scraper without first reconstructing these foundations yourself. The first few floors of our skyscraper consist of advanced mathematical formalisms that turn the Classical Physics theories into beauties of their own. They are needed if you want to go higher than that.”
This second I would also agree with:
“It is argued that the so-called holographic principle will obstruct attempts to produce physically realistic models for the unification of general relativity with quantum mechanics, unless determinism in the latter is restored. The notion of time in GR is so different from the usual one in elementary particle physics that we believe that certain versions of hidden variable theories can -- and must -- be revived.”
[Quantum Gravity as a Dissipative Deterministic System-Author Gerard 't Hooft-1999]
Truly all I am certain of is that if we are ever to be able to find a theory that would mesh QM with GR, then QM will have to become a theory that when the question “how?” is asked the answer offered will have to be something other then “because!”; that is since from this one can go no further, as it offers nothing that could be considered as an explanation.
Best,
Phil
Hi Phil,
ReplyDelete‘Beable or not a beable, that is the question?’
Gerardus t'Hooft will answer your Shakespearean point on "the Beable" most certainly:)
“Theoretical Physics is like a sky scraper. It has solid foundations in elementary mathematics and notions of classical (pre-20th century) physics. Don't think that pre-20th century physics is "irrelevant" since now we have so much more. In those days, the solid foundations were laid of the knowledge that we enjoy now. Don't try to construct your sky scraper without first reconstructing these foundations yourself. The first few floors of our skyscraper consist of advanced mathematical formalisms that turn the Classical Physics theories into beauties of their own. They are needed if you want to go higher than that.”
This quote you selected of Hooft's is one I was going to place at Bee's blog entry of Model's Theories and such. My responses there are directly related to the points you have shared here.
To understand the full scope of what is happening at PI was a education for me in determining the differences between approach?
Understanding the "Bohemian position" and how "this derivative" is measure of the lineage we had been talking about here. I will most certainly move on from that point to show you how far this development has been considered and the current information that Dorigo has been writing in terms of the Calorimeters.
Approaches to the Quantum Theory of Gravity by the PI Institute
Two methods evolved in the theory of elementary particles to describe such quantized flux tubes. The one, called the loop method, studies them using the basic laws of electricity and magnetism, combined with quantum theory. The second, called string theory, postulates that the quantized flux tubes may be treated as fundamental in their own right, and the laws of electricity and magnetism derived from them.
Many theorists believe that these two points of view are actually equivalent—just different ways of studying the same thing from different points of view. The idea that they are the same is called duality, which here, as in other areas, signals that the same object is being studied with different ideas and methods. See Here
While I seek ingenuity in those creative moments it would be with the understanding that such a "joining of" and "connection too" the source is that Indecomposable moment that Alain Connes talks about. If it already existed mathematics only has to be "discovered" and, is not Invented.
Alain Connes
Where a dictionary proceeds in a circular manner, defining a word by reference to another, the basic concepts of mathematics are infinitely closer to an indecomposable element", a kind of elementary particle" of thought with a minimal amount of ambiguity in their definition.
This relates directly to your thoughts on the distinction of those who are of the ilk of the elementary "one of the one" reference to Feynman.
Why I ask Bee to reduce it the way I did in terms of the Mind Map of Numerical relativity.
I would not draw these distinctions if I did not already go to great lengths to understand how the model and perception of Theory and model must be understood from the likes of the relations I pointed out in Magritite. When is a Pipe a pipe?
Where shall such a model begin and where shall it end? This had to be included in Models and Theories.
The way this interaction is considered, had to be in relation to how Feynman's toy model are included in the understanding of the interactions.
That String theory would have been recognizing the foundational aspects demonstrated in Hooft's quote was also very important to consider. "Summing over paths" are then part of the realizations of the approach that String theory uses. It includes Feynman method.
Hi Plato,
ReplyDelete“That String theory would have been recognizing the foundational aspects demonstrated in Hooft's quote was also very important to consider. "Summing over paths" are then part of the realizations of the approach that String theory uses. It includes Feynman method.”
If one looks at Einstein’s vision, that all is a collection of “nows”, where then is there space for “histories” that are to be considered yet never realized? Bohm’s approach does have room for this, which is a place called configuration space. This space although higher dimensional is not of dimension as described in string theory, which also requires physicality, yet is a realm of potential which while not real in the physical sense is real in the considered one. I think we place too much emphasis to imagine that dimension can exist only in the physical and that perhaps the world itself is something more then this.
Best,
Phil
Hi Phil,
ReplyDeleteI think we place too much emphasis to imagine that dimension can exist only in the physical and that perhaps the world itself is something more then this.
I have done some research work on "configuration space" as you have mentioned it. I need to think about this some more.
Phil:This space although higher dimensional is not of dimension as described in string theory, which also requires physicality, yet is a realm of potential which while not real in the physical sense is real in the considered one.
I think the perspective still stands that within the confines of perspective about time, that we are pushing back perspective still within context of this universe. It had to "already exist" for us to even observe it.
The "multiplicity of the rotations within a coordinate locations" within that space, is much more dynamical as you send the mind ever deeper into the universe's structure. You are in essence pushing perspective back to a time near it's beginning.
It could not be inconsistent with the observations about the QGP?:)
This is a useful primer on determinism, indeterminism, and metaphysics (i.e., libertarianism), thanks...
ReplyDelete