Indeterminancy in physics

Poster, I wholeheartedly agree with you that it matters not a whit what our metaphysics tells us, when assessing QM. Physicists seldom concern themselves with philosophical questions, and it would not necessarily make them better at their job if they did. All we need know is that QM works astonishingly well. It makes testable predictions about the macroscopic world and has led to actual discoveries about the world that could not have been known beforehand (would Xris or Schaps like to explain this?). Of course, something might come along to replace (or improve upon) QM, but the existent experimental results cannot be gainsaid. A new paradigm still has to satisfy these results, even if they turn out to be just a subset of a new set of results (just as Newtonian gravitation is a low-mass approximation of general relativity). There also cannot be any local hidden variables in QM, if Bell's theorem is to be believed.

I don't think reality exists in ordinary space-time as Einstein implies...

To my mind, everything I've read about the evolution of QM experimentation and theorizing implicates space-time as being non-objective. Intuitively, if one allows space-time to exist as an attribute (or emergent property) of "something else," quite a number of paradoxical or non-intuitive artifacts of our conceptual systems begin to disappear.

Personally, I think space-time is neither objective (Newton) or emergent (Leibnitz). Both of these conceptions seem to treat time as independent of conscious subjects. I'm aware that most physicists are uncomfortable with time (if not space) as an emergent property. After winning the Nobel Prize for physics in 2004, string theorist David Gross said: “It is very hard for me to imagine a formulation of physics without time as a primary concept because physics is typically thought of as predicting the future given the past. We have unitary time evolution. How could we have a theory of physics where we start with something in which time is never mentioned?” It is diffcult to deny that QM predicts the future given the past, even if we don't know the total state of the system at any one time. After all, Schrodinger's equation has time as a key variable.

In this debate, we are being forced to consider the nature of causality itself and, by implication, the identity of physics. Physicists like Hawking tell us that time and causality came into existence at the instant of the Big Bang; and yet one still feels compelled to ask what caused this stupendous event. Causation is a condition of physical thinking, and even QM probabilities depend on it. While on the topic of thinking subjects, I wonder why QM is often talked about as non-intuitive, or antithetical to 'classical exprience' ? QM can justifiably be said to be non common-sensical, but so are negative numbers and surely the word 'intuitive' can just as easily be used to describe the elegant mathematics of QM as Newtonian mechanics or relativity.

Anglan why should the opposition to a indeterminate universe make the technological advances from quantum impossible? A false concept does not hinder technology. Do we have to know exactly what magnetism actually is before we make a compass? If you accept Bells theorem not only do you have to reject hidden variables you have to accept particles can travel faster than light or even instantaneously. That is if these particles actually exist or are they another manifestation of another concept that is hard to accept.

If you do not know what you are measuring then the results will appear indeterminate. The apparent randomness that indicates an indeterminate quantum universe could be our ignorance, not an indeterminate nature. Hidden variables are completely ignored and concepts are accepted with religous fervour. .

I don't see how you can credibly claim hidden variables are completely ignored. It's just not true.

After the famous 1964 paper of John Bell which suggested experiments to test the possibility of local hidden variables, many experiments have followed. While not completely decisive, these experiments have considerably reduced possibilities for local hidden variables. There has been great interest in new experiments that could settle the issue and possibly rule out local hidden variables completely.

The work on non-local theory of David Bohm, one of the outstanding quantum theorists of the century, is still in print twenty years after his death and viewed by many physicists as a possible answer.

A recent survey article on progress in this field by Marco Genovese is available online. It mentions a 1999 proposal of Nobelist Gerardus 't Hooft that determinism may appear at Planck scale and dissipate with loss of information at larger scales.

The article contains a list of 505 references. That seems a awful lot of references for something completely ignored, doesn't it? You can find the article at

http://arxiv.org/abs/quant-ph/0701071.

So if certain individuals are considering hidden variables why are they ignored and the quantum world is still claimed to be indeterminate in concept? I make no claim that hidden variables exist except to say a concept that makes Alice in wonderland look sensible needs to be re assessed. 80 years and billions of pounds have been spent pursuing a concept that makes claims then before the ink is dry makes a counter claim. Mathematical magicians and quirky particles deny the common man a reasonable chance of even questioning these so called concepts. How much more dogmatic attention to a concept can we afford to give science. It has become the new alchemy of science searching for a gold that has no value.

So if certain individuals are considering hidden variables why are they ignored and the quantum world is still claimed to be indeterminate in concept? I make no claim that hidden variables exist except to say a concept that makes Alice in wonderland look sensible needs to be re assessed. 80 years and billions of pounds have been spent pursuing a concept that makes claims then before the ink is dry makes a counter claim. Mathematical magicians and quirky particles deny the common man a reasonable chance of even questioning these so called concepts. How much more dogmatic attention to a concept can we afford to give science. It has become the new alchemy of science searching for a gold that has no value.

[my emphasis]

Quantum mechanics is still indeterminate because Hermitian operators in Hilbert space need not commute. Hidden variables are not adopted as the leading explanation because they are unknown and experiments suggest that eventually it may be possible to rule them out.

Unfortunately advanced mathematics and physics are not democracies in which objections of the common man carry weight. The price of admission is very high: you must first completely learn and understand what has been accomplished to date. That price increases with every new discovery. It's just very hard stuff.

Anglan why should the opposition to a indeterminate universe make the technological advances from quantum impossible? A false concept does not hinder technology. Do we have to know exactly what magnetism actually is before we make a compass?

Xris, Of course we have to accept that technology can exist without science - the ancient Chinese proved that. I was talking about QM uncovering facts about nature. It resolved questions concerning the structure of stars, the nature of superconductors, and the properties of magnets.

Well this is matter of opinion and not exactly factual. For every concept and lets be clear quantum is a concept not a scientific fact there could be a hundred competing concepts. The problem arises like the BB when well known scientists hang their reputation on one particular concept the others are completely ignored and marginalised. As problems arise with these concepts invention becomes the norm, magical mathematics and strange conclusions become acceptable. A few see problems but still persist with the concept not quite understanding why their particular objections fail to impact. Are we really expected to believe in possible one electron in the universe or a particle that might not be a particle which can travel faster than light? A photon that is stranger than Tinkerbell? We even find the BB another strange concept supporting particle science,completing the magic circle. No I do not understand quantum science but I doubt very much if there is one soul here on this forum that can truly say they do. We have to ask why?

If you accept Bells theorem not only do you have to reject hidden variables you have to accept particles can travel faster than light or even instantaneously.

This isn't true. If you accept Bell's theorem you have to reject local hidden variables. You don't have to reject hidden variables, as long as they're non-local, and you don't have to reject locality, as long as you reject hidden variables. You have to reject one or the other, but not necessarily both.

Well this is matter of opinion and not exactly factual. For every concept and lets be clear quantum is a concept not a scientific fact there could be a hundred competing concepts.

So provide us with a competing concept to the notion of the quantum and your version of Planck's Law that goes with it.

No I do not understand quantum science but I doubt very much if there is one soul here on this forum that can truly say they do. We have to ask why?

Lack of study?


You reject much of modern physics—not because you have studied it carefully and found problems—but because you haven't studied it and what you've heard does not accord with your personal intuition. You think those who practice the art must be deluded, stupid, and dishonest. Do you believe your personal intuition is the ultimate judge in physics?

Andlan says,

Personally, I think space-time is neither objective (Newton) or emergent (Leibnitz). Both of these conceptions seem to treat time as independent of conscious subjects. I'm aware that most physicists are uncomfortable with time (if not space) as an emergent property. After winning the Nobel Prize for physics in 2004, string theorist David Gross said: “It is very hard for me to imagine a formulation of physics without time as a primary concept because physics is typically thought of as predicting the future given the past. We have unitary time evolution. How could we have a theory of physics where we start with something in which time is never mentioned?” It is diffcult to deny that QM predicts the future given the past, even if we don't know the total state of the system at any one time. After all, Schrodinger's equation has time as a key variable.

Might such a renown physicist see just how correct he is (physics can't be formulated without time) yet not consider the most obvious reason why: that humans' capacity for abstract conceptualization and symbolics has precipitated physics as an ad hoc invention in response to our perception of spatio-temporal separation. Extention and duration are two of the primal gestalts of cognition, the cognitive sciences tell us. Even Kant gave them a special status in the phenomenal world. It is only natural that we should build all our cognitive frameworks and edifices upon their foundation.

In this debate, we are being forced to consider the nature of causality itself and, by implication, the identity of physics.

I underscore this statement. Nothing less is at stake.

Physicists like Hawking tell us that time and causality came into existence at the instant of the Big Bang; and yet one still feels compelled to ask what caused this stupendous event. Causation is a condition of physical thinking, and even QM probabilities depend on it.

I'll agree, as long as I can add the word "conceptually" to the end of your last sentence. I don't think QM probabilities depend on causation physically, simply because I don't grant probability any existence beyond an artifact of enumerative thinking. And even if it turns out that causation may be somehow hardwired into human conceptualization, still that may be nothing more than an evolutionary advantage for beings who interact with their environment at a predominantly macroscopic level.

As far as I'm concerned; this subject was built on wavering grounds.

Quantum physics is as close to the truth as any other school of subjective thought.

As far as I'm concerned; this subject was built on wavering grounds.

The Schrödinger wavering equation?

As far as I'm concerned; this subject was built on wavering grounds.

The Schrödinger wavering equation?

In other words this subject is unstable.

Well this is matter of opinion and not exactly factual. For every concept and lets be clear quantum is a concept not a scientific fact there could be a hundred competing concepts. ..........No I do not understand quantum science but I doubt very much if there is one soul here on this forum that can truly say they do. We have to ask why?

Xris, I agree with you that there could be other accounts of the same phenomena, and I agree that our intuitions that QM is not the whole truth should be respected. I guess I would disagree that there could be other equally valid scientific accounts, since QM seems to me to be as well supported as any other branch of science. After all, classical physics deals with strange mathematical concepts like complex numbers and Hilbert transforms, so this is not exactly new. I am not a relativist like you, because I believe that QM does offer a powerful explanation of natural phenomenon. I don't think we should be overly concerned that QM demonstrates nature to be indeterminate because indeterminacy does not mean non-causal, and temporal spatial 'physical' nature is not the whole of reality anyway. Indeed, this is what I mean when I say we must respect our intuitions. Science cannot explain how the world is there 'for us'. We want nature always to succumb to our concepts, our theoretical structures, when plainly it cannot always fulfill this function.

If you accept Bells theorem not only do you have to reject hidden variables you have to accept particles can travel faster than light or even instantaneously.

This isn't true. If you accept Bell's theorem you have to reject local hidden variables. You don't have to reject hidden variables, as long as they're non-local, and you don't have to reject locality, as long as you reject hidden variables. You have to reject one or the other, but not necessarily both.

Well you had better tell others that.So the decay of radioactive atoms could be determined if we knew the hidden variable?

-- Updated Thu May 24, 2012 7:32 am to add the following --

Well this is matter of opinion and not exactly factual. For every concept and lets be clear quantum is a concept not a scientific fact there could be a hundred competing concepts.

So provide us with a competing concept to the notion of the quantum and your version of Planck's Law that goes with it.

No I do not understand quantum science but I doubt very much if there is one soul here on this forum that can truly say they do. We have to ask why?

Lack of study?


You reject much of modern physics—not because you have studied it carefully and found problems—but because you haven't studied it and what you've heard does not accord with your personal intuition. You think those who practice the art must be deluded, stupid, and dishonest. Do you believe your personal intuition is the ultimate judge in physics?

I have no intention of matching one ill conceived concept with another. I do not misjudge science as a whole but I do this reasonable modern phenomena of theoretical science. They are self indulgent and just as dogmatic as any religious dogma. I do not have to study the subject it only requires a logical mind to evaluate their contradictory findings. You tell me how a particle with mass can travel faster than a photon, a particle that is proposed as having no mass? Do you really believe the observations indicate space and time has no value? Sorry but this poor ignorant fool is not going to let any high priest dictate from the heavens without question.