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kevin1981
2010-Jun-21, 04:42 PM
I have started this thread because i am very interested in the subject of open realism and thought it would not be appropriate to carry on the discussion in the "What is space" thread.


Kevin,

Yes, that’s basically the philosophical stance that I hold, though the thinking behind that stance extends far beyond the example I gave of non locality of particles between a source and sink. My reasons for holding that stance are primarily derived through Ken G on this forum and the writings of Bernard d’Espagnat who as a physicist has thought about and written extensively on the conceptual foundations of quantum mechanics. As a philosopher he has used his knowledge of quantum mechanics to suggest that the weak objectivity at the quantum level can be shown to also exist at the macroscopic level if one considers quantum mechanics to be universal. The arguments he uses for the extension of quantum mechanics to macroscopic reality (and hence concepts of space and time) involve dechoerence theory.

What this means is that we can never escape from observer dependence, thus the scientific method which is based upon separating the observer from the observed is valid only within the remit of intersubjective agreement between sentient beings. That intersubjective agreement provides us with empirical reality, it is a scientific reality that cannot be separated from the observer, thus cannot be claimed to be the same as nature that exists outside of the combination of observer and the observed.

On this basis, nature as it exists outside of sentient beings cannot be addressed through the scientific method, what does exist may be of a form that we have no experience of – we just don’t know. So my philosophical stance of open realism is simply that – the “something” that exists independently of the observer (and importantly, I do consider there is something, albeit of a form that is unfamiliar to us, I don't consider that we entirely construct our reality in our heads in the manner of radical idealism) that is open, not reachable through science.

Now D’Espagnat considers nonseparability to be of fundamental importance within quantum mechanics. The correlations of nonseparability are shown through Bells theorem to be non local. Bells theorem is not something that can be replaced with Bell’s theorem Mk2 in the manner of a new or modified theory, the non local aspect is with us for ever. That it sits side by side with our local macroscopic reality gives rise for d‘Espagnat to (philosophically) consider that nature as it exists outside of the bond of observer and observed to be non local, in other words devoid of space and time. I agree with this, and whilst it may feel uncomfortable, I feel far more uncomfortable with notions of infinite distance, of the physical universe never ending. That to me seems bizarre, but within my philosophical framework, those notions of infinite distance show up as the breakdown of our macroscopic reality. By considering that space and time are constructs of our brains, questions of macroscopic notions of infinite distance are simply extrapolations we make from familiar measurements of distance and do not figure as such within nature as it exists outside of sentient beings.

The issue of observer dependence is the crux of this, and it is an aspect that Ken G has developed through his philosophical investigations of physics. He and d’Espagnat come to pretty much the same conclusions by slightly different routes, d’Espagnat starts from quantum mechanics, whereas Ken stars from basic philosophical problems that show up within macroscopic reality, but quantum mechanics forms an important part of his analysis.

It must be properly understood, that this position is entirely philosophical, it is not a scientific position. But likewise I consider that physical realism (that assumes space and time to be real, existing in the same familiar form outside of the observer) is also a philosophical position. This is simply because the primary bed rock of science – namely strong objectivity, may in fact be only of a weak variety. Scientifically we cannot mitigate for the brain because whatever model we build to represent the effect of the brain is, in itself a product of that brain. We cannot stand apart from our place within macroscopic reality and produce a mitigating model of sentient beings that could be used to establish the difference between nature within and outside of our involvement. That particular view – that physical (or objectivist) realism is a philosophical stance is very controversial and gives rise to many, often heated, arguments on this forum. But just keep in mind my basic premise – can we scientifically determine the level (if any) of observer dependence, given that philosophical investigations and lessons from quantum mechanics suggest that observer dependence is a real issue to be considered within physics? To my mind we can’t just sweep this issue under the carpet, we have to acknowledge it and move on from that point.

There is a lot to this, and this post perhaps is a long winded reply to your basic question, but I think it important for you to understand why I hold this position. It is not based on some philisophical ad hoc whim, it is based on the writings and research of practicing physicists - in d'Espagnat's case he worked at Cern for many years and was a collegue of John Bell, he oversaw the correlation experiments by the Alain Aspect group and has written extensively on this subject area including the considered classic "conceptual foundations of quantum mechanics". There is much that I don’t understand properly yet, but it makes one question the assumption that we are here, looking at the world out there. I don’t think we are, we are part and parcel of everything that we experience. What I find inspiring is that we see scientists like Ken G and d’Espagnat putting these ideas forward as opposed to pure philosophers who have tended (according to d’Espagnat) to ignore the contribution quantum mechanics can make to their philosophical views on the nature of reality.

Thanks Len, that was a great reply. I was hoping i understood you right as since reading what you wrote it has left me thinking about it all day. I have never come across this "open realism" subject before, but it has really got me thinking and i would like to learn more about it.

The reason why, is that it actually seems like common sense, to me at least, that the world is made up from the smallest constituents upwards. I have known for a while that everything comes from the quantum level and upwards, but what really has me excited (if i am honest) is the possibility that space and time are also from that domain. I had'nt really thought about the fact that at the quantum level there is no time or space.

To be honest, i did not know there was not any space at those levels. I have lots of questions, so if you and Ken G do not mind i would like to pick your brains. Some of the terminology you use i do not understand though, so maybe you could go easy on me ;)

So i guess i should start of by asking why is there no time and space at these tiny distance scales?

What is observer dependence, i don't fully understand what that means.

Many thanks

Ken G
2010-Jun-21, 07:50 PM
The reason why, is that it actually seems like common sense, to me at least, that the world is made up from the smallest constituents upwards. I have known for a while that everything comes from the quantum level and upwards, but what really has me excited (if i am honest) is the possibility that space and time are also from that domain. I had'nt really thought about the fact that at the quantum level there is no time or space.It might be safer to say that in quantum mechanics, space and time are treated rather differently than in classical mechanics or relativity (there is a relativistic version of quantum mechanics, but it's just a hybrid theory, a kind of "shotgun marriage" of these different perspectives). Time is a parameter of the theory, and distance is an observable, but the fundamental space is the space of wave functions and the operators that act on them-- distance being one such operator. Time is not part of that space at all, it is an external parametrization that we know how to use by its role in the predictions quantum mechanics makes.

So i guess i should start of by asking why is there no time and space at these tiny distance scales?It starts with the idea that in quantum mechanics, the reality of the situation includes the questions that are being posed in that reality, you cannot get away with thinking that the answers to the questions you could ask are hypothetical answers to hypothetical questions. The classic example of such a hypothetical question/answer is "which slit did the photon go through" in a double-slit experiment-- if there is no apparatus in the reality to establish that answer, then the question itself has no physical meaning, and neither does it have an answer. Note that the role of space in classical mechanics is normally formulated as though the motion of the object through space was constantly being observed and quantified, all the while assuming that this process has no effect on the motion of the object. That's fundamental to how space gets used in classical mechanics, it's part of the very meaning of our word "space." But it doesn't work in quantum mechanics-- to give space that meaning, you'd need constant measurement to determine the particle location, and the results of such experiments would be quite different from the ones we normally talk about that do not have such an apparatus in place.


What is observer dependence, i don't fully understand what that means. The above is what observer dependence means-- gaining knowledge about reality requires posing questions via elements that must exist in the reality we are posing the question to. The question, and its answer, are part of the reality that is being treated. The way I like to put it is, a question never posed is also never answered. This is logically true even in classical mechanics, but there we often get away with ignoring it, especially if we tend to confuse the reality with our own idealizations about the reality. Not so in quantum mechanics, where the idealizations we make must correspond to the actual reality or the results of the experiments come out different from our predictions.

kevin1981
2010-Jun-21, 08:42 PM
To be honest, most of what you just wrote i don't understand. That is not meant to be a criticism by any means, it is because i can not wrap my head around it ! What excited me earlier was the fact that space and time are possibly not real when it comes to fundamental truths. I have always thought that everything is connected some how, i just have not thought a great deal about the fact that it all stems from the planck scale upwards. So what we perceive as the real world is just a layer on top of another layer until it reaches the quantum planck scale. And from what i can make out, that is the "real" reality.

And from what i know, phenomena at those levels are truly bizzaire and we really don't understand it fully. In short, is what i just described, open realism?
Because to me, reading Len's post earlier was a real eye opener, and it makes complete sense. Is it a fair statement to say that basically, everything we perceive as real, is just discreet units of energy interacting with one another ?

Also i watched this youtube video and wondered if you had already seen it and do you agree with what the man is saying.

http://www.youtube.com/watch?v=sTJZdRPXcrg&feature=related

Ken G
2010-Jun-21, 10:55 PM
And from what i can make out, that is the "real" reality.I'd say that's something of a stretch-- you're saying that given that the things we understand pretty well are not the reality (which I agree with, expressly because we understand them pretty well), it must hold that things we don't understand at all must be the reality. I don't think that follows.

In short, is what i just described, open realism? The first part is, but not the second part, about the Planck scale.


Because to me, reading Len's post earlier was a real eye opener, and it makes complete sense. Is it a fair statement to say that basically, everything we perceive as real, is just discreet units of energy interacting with one another ?
I'd say it's a fair statement that everything we perceive as real is not quite (or not at all) as we perceive it to be, yet we do the best we can, and invent constructs like "discrete units of energy interacting with each other."

Also i watched this youtube video and wondered if you had already seen it and do you agree with what the man is saying.
Summarize it for me, I had trouble accessing it.

kevin1981
2010-Jun-22, 02:33 AM
I used the planck scale because Stuart Hammeroff was talking about it in the video. From now on i will think more in the line of, what we perceive to be real is just constructs built from the quantum domain.(Including time and space)

Physical realism is the counter argument which is what? Is it along the lines of, we have evolved consciousness and what we see as time and space is real, there is no underlying reality because space and time is our reality.

In other words, observer dependence means we can only make sense of stuff in our perceived reality, anything outside of it we don't know about. So we are entwined in our reality and can not see past it?

kevin1981
2010-Jun-22, 03:29 AM
Where does this statement stand, conscious observers create reality, without observers there is no reality. Or, the actual act of observing creates reality.

They are two quotes from youtube videos.

Now i am interested in consciousness too.

The thing i find frustrating is, i am interested in these subjects but there is so much to know that i find it hard to remember everything i hear and read. I tend to go over subjects again and again, each time i do learn a little more through !

Ken G
2010-Jun-22, 07:59 AM
I used the planck scale because Stuart Hammeroff was talking about it in the video.The Planck scale is the fundamental physical scale we can make from the constants of our current theories. However, we are in the curious position of knowing that the fundamental scales we can make from our theories are scales on which are our theories must break down, because quantum mechanics is inconsistent with general relativity. That is why physics, as an axiomatic structure, is fundamentally inconsistent, and the meaning of its laws do not follow from the meaning of the basic constants that appear in those laws. That's a really surprising aspect of physics, especially since the laws work so well. But this also means that the laws of physics cannot be "built up" from the Planck scale, instead they must avoid the Planck scale like the plague.

But it seems natural to expect the laws break down long before you get to the Planck scale, so I never like the claim that the laws of physics should apply down to the Planck scale. The way I would put it is, the laws of physics are an "effective theory", a theory that works but is not a self-consistent description, because its fundamental parameters do not generate a working theory at the fundamental scales of those parameters (the Planck scale). My opinion on this seems to fly in the face of those who like to imagine that quantum mechanics is the "true theory", they simply assume without support that once the inconsistencies are resolved, if they are ever resolved, the result will still look like quantum mechanics. I have no idea why they think that, it seems highly unlikely to me.


Physical realism is the counter argument which is what? Is it along the lines of, we have evolved consciousness and what we see as time and space is real, there is no underlying reality because space and time is our reality. Something like that, I don't really know what naive realists claim, it just doesn't make sense. But there is a form of realism that makes sense, which is representational realism (which seems similar to "open" realism). Here we just say that although reality may well exist outside of us, we only have access to our own interactions with reality (perceptions and contemplations), so we can only talk about internal representations that we build as a result of those interactions. This is still a form of realism, because it asserts the existence of a reality outside of us, but it places the scientific method within the confines of the representations, rather than the reality itself. I can't see any meaningful alternative, frankly.

In other words, observer dependence means we can only make sense of stuff in our perceived reality, anything outside of it we don't know about. So we are entwined in our reality and can not see past it?Exactly.

Ken G
2010-Jun-22, 08:17 AM
Where does this statement stand, conscious observers create reality, without observers there is no reality. Or, the actual act of observing creates reality.I'd call that "idealism", and I wouldn't exactly agree with it-- to me, scientific thinking benefits from some flavor of realism. We can say the reality exists independently of observing it, but we can't say anything about it without observing it, and the observation is then part of the reality we are saying something about.


Now i am interested in consciousness too.
I'd have to say consciousness is lurking in the background of all this, but I don't think we even begin to have the language yet to include it meaningfully. There's so much more work to do before we can understand how consciousness enters, and it may even be impossible, given that our viewpoint comes from within that consciousness, not outside it. My own feeling is that we should avoid statements like "consciousness causes reality" in favor of statements like "reality causes consciousness"-- we must put consciousness at the end of the chain, because it's our viewpoint of last resort.


The thing i find frustrating is, i am interested in these subjects but there is so much to know that i find it hard to remember everything i hear and read. I tend to go over subjects again and again, each time i do learn a little more through !The topics are too difficult, and are very open to personal opinion. When it comes to these issues, I'm not sure we're any better off than the ancient Greeks trying to understand lightning.

Strange
2010-Jun-22, 09:28 AM
Can I try and summarize (part of) the range of philosophical views which might help Kevin (and me). I'm sure Ken will want to correct some of this...

Take the simple example of seeing something that is red (a flower, say).

The idealist may say that there is no such thing as a flower, or red, and we have created those things in our consciousness. The extreme version of this is solipsism, which says that I am the only conscious being in the universe and everything else, including other people, are created by my mind (possibly 30 seconds ago). I guess the idealist would say that the flower doesn't (or may not) exist if no one is looking at it (in as much as it exists at all).

At the other extreme, there is the physical realist who says that the flower really exists and its nature is just what we perceive it to be. Including its "redness". The physical realist will say that, of course the flower exists when no one is looking at it: it is a "real flower" after all.

In between, there are various degrees or interpretations of realism.

Some may say that the flower exists in largely the form we experience it. We can perceive various attributes (touch, smell, color) but the experience of the color "red", for example, only exists in our mind. We can't directly transfer our experience of "red" to someone else, we can just label it as "red" or make comparisons with other things that appear "red" to us. The actual effect of "redness" is created by our eyes and brain. "Red" is not a thing which exists outside of ourselves.

Then I guess you can argue about the degree to which something "out there" actually corresponds to what we perceive as "red". Do different wavelengths of electromagnetic radiation actually exist, or are they just mental constructs we create based on measurements we make and interpret to create a model of the world?

This is not too difficult when you are dealing with the macroscopic world because we can share experiences (feel this, it is "soft"; see this, it is "red"). And, probably, our brains have evolved some intuitive understanding of many of the things we experience (which, of course, may or may not correspond to what is "really" there).

When you get to the level of quantum mechanics, things do not behave like the things we are familiar with, so we can only describe them using math or analogies (it is particle-like, it is wave-like). What is "really" there is not a particle or a wave; it is just what it is. All we know about it is through the measurements and observations we make with which we construct a mental model. And, of course, our attempts to measure it have an effect on it, so we cannot take any sort of objective view of it.

I get the impression that the open realism described by Len and Ken (sounds like a comedy duo) says that we can be no more certain about what a flower "really" is than we can about quantum entities. Especially as macroscopic objects are (or appear to be) simply manifestations of quantum effects on a larger scale. And that includes our own sense organs, brains, etc.

Would the open realist say that to ask if the flower exists when no one is looking at it it, is not a meaningful question? I.e. we can only know anything about the flower by observing it; we cannot deduce anything about it when no observations take place. (That would seem to be the case with the quantum world, anyway).

Bottom line: most versions of realism say that there is "something" out there (reality exists) but we can only know it as the mental model we create of it.

I'm not sure if any of that is either accurate or helpful.... (writing it down helped me, so I hope it is reasonably accurate :))

kevin1981
2010-Jun-22, 01:41 PM
My own feeling is that we should avoid statements like "consciousness causes reality" in favor of statements like "reality causes consciousness"

Sure, to me it makes more sense that, reality causes consciousness because it gives consciousness something to be made out of.

Thanks Ken and Strange for your reply's, i will continue to read up on these topics of reality and the connection to QM as i find it very interesting.

Ken G
2010-Jun-22, 01:51 PM
Can I try and summarize (part of) the range of philosophical views which might help Kevin (and me). I'm sure Ken will want to correct some of this...No corrections, that all sounds fine to me.


Would the open realist say that to ask if the flower exists when no one is looking at it it, is not a meaningful question? I.e. we can only know anything about the flower by observing it; we cannot deduce anything about it when no observations take place. (That would seem to be the case with the quantum world, anyway).All flavors of realism would say that something exists there even when no one is looking at it, but open realism asserts that we can't answer any questions about what exists without implying that an observation is taking place. Whatever we need to know about it before we can decide that it is a flower, or a red flower, requires that there be some kind of observation. The observation can be hypothetical, in which case its outcome is statistical rather than actual (like a card player calculating the probabilities of what they will see when their opponent reveals their cards), but any answer to a question comes in a package with the observation that can determine that answer. That, in turn, implies the participation of the observer.


Bottom line: most versions of realism say that there is "something" out there (reality exists) but we can only know it as the mental model we create of it. Exactly, although to nitpick I might substitute the word "understand" where you have "know." To me, what we can know are the outcomes of the observations, and what we can understand are the mental constructs we form from those outcomes. The distinction is a bit arbitrary, as we must also understand our own observations using other kinds of constructs, but there would seem to be levels of directness between what we can know as a raw measurement, and what requires substantial processing, like a law of physics.

kevin1981
2010-Jun-22, 07:36 PM
If at the fundamental level, there is no space and time, then how do we account for there being a reality in the 1st place. Because as humans, we have a pretty successful model of how the space and time came into being.(well from around a second after) We have evidence like the CMBR and we see galaxy's red shifting away from us and more, so to us humans, the big bang model fits the data. So if there is a deeper layer of reality and what we perceive to see is really a construct of something else, then where did that come from.

As i was writing that paragraph, i thought of the observer dependence issue. Would i be right in saying that we can't answer my question because all we can observe is the reality we see. Though from our perspective the big bang model makes a lot of sense. I guess i am just thinking out loud here, but i am sure you see where i am coming from.

Ken G
2010-Jun-22, 08:07 PM
If at the fundamental level, there is no space and time, then how do we account for there being a reality in the 1st place. There are many things we do not attempt to explain, we merely choose to accept because we think it simplifies our language. So it is with all forms of realism, but open realism takes pains not to let that stance introduce demonstrably incorrect elements into our interpretations.

Because as humans, we have a pretty successful model of how the space and time came into being.Certainly, but the success of a theory is not a demonstration that it is the actually reality. Indeed, the history of science is rife with examples of successful theories that we later discovered were definitely not the reality, the most glaring example being Newton's laws.

So if there is a deeper layer of reality and what we perceive to see is really a construct of something else, then where did that come from.
Why do we need a reason to suspect a deeper layer of reality? "More than meets the eye" seems like a natural default stance. Indeed, we have rarely made a new observation of a regime that had not been seen before without making some new discovery.

Would i be right in saying that we can't answer my question because all we can observe is the reality we see. Though from our perspective the big bang model makes a lot of sense. I guess i am just thinking out loud here, but i am sure you see where i am coming from.Yes, we can agree that we have an excellent model, we just have to decide what stance we will take as to what that means. Does it mean we have created a good internal representation of the actual reality? Certainly, it is undeniable we have done that. Does it also mean that the internal representation is the same thing as the reality? I see no reason to take that leap, and certainly nothing in the history of science that supports it.

Len Moran
2010-Jun-23, 08:27 AM
Kevin

Many of the questions I address to myself are commented upon by Bernard d'Espagnat in his book "On Physics and Philosophy", and judging by your questions, that book would be relevant to yourself. It is not an easy read (it is not a "popular science book" by any stretch of the imagination), but it is accessable with some effort (well I had to extend some effort at least).

You will find that there is much overlap with Ken G's writings and both perspectives compliment each other.

I don't offer this book at all as a definitive answer to all these problem questions of observer dependency, it is a philosophical perspective based on his acknowledged expertise in quantum mechanics. But since d'Espagnat has always been interested in the philosophical side of physics from early on in his career, there is a real sense in his writings that he has always thought hard about the relationship of his physics to that which the physics actually represents.

I think the book is only available in hardback, but is readily available on line and in booksellers.

Luckmeister
2010-Jun-23, 05:41 PM
In the macro world, the term I would use to define human existence is "pragmatic reality." We build our model upon a consensus of what our senses tell us and use our perceptions to aid us in relating to our environment in an efficient, consistent and enjoyable manner. Whether any of it really exists exterior to us is at best a moot point. Bottom line -- If what we sense works, use it.

Mike

Ken G
2010-Jun-23, 07:08 PM
Whether any of it really exists exterior to us is at best a moot point. Bottom line -- If what we sense works, use it.
This is a very important issue, because it should be mentioned that sometimes our philosophical perspective actually does impact our ability to do better physics. There is certainly no reason to advocate one form of realism over another, or over idealism, if none of these stances impacts in any way our ability to understand our current physics, or our ability to navigate the waters of future developments. But they do have those kinds of effects-- the philosophical stance informs our language about what our theories mean, and help us look to new directions. Those who say "shut up and calculate" virtually never do.

The classic example of this is how Einstein's adherence to the positivist stance that only what can be observed is actually real informed his choices about how to construct a theory of relativity. But there are other examples too-- Faraday's experiments led to the formation of a philosophical stance that all of reality was not encompassed by its material elements, which motivated the way Maxwell's equations elevate the role of fields to an equal footing with the role of material particles. The equations in these theories can exist without any philosophical framework, yet having such a framework helps us derive them, helps us use them, and helps us understand what they mean.

What's more, ontological language in science is both routine and useful, so finding the most facile and appropriate philosophical stance does impact on the functioning of science. It also informs the process that we all hope science is engaged in: beyond just making correct predictions, it is bringing us closer to understanding our reality. But if that means understanding our role in how we form that understanding, then so be it. Personally, I think that at some point, we will inevitably hit a brick wall where no further advancement of scientific understanding will be possible until we understand our own role in that understanding. Indeed, that point may already be here.

Len Moran
2010-Jun-23, 11:29 PM
What's more, ontological language in science is both routine and useful, so finding the most facile and appropriate philosophical stance does impact on the functioning of science. It also informs the process that we all hope science is engaged in: beyond just making correct predictions, it is bringing us closer to understanding our reality. But if that means understanding our role in how we form that understanding, then so be it. Personally, I think that at some point, we will inevitably hit a brick wall where no further advancement of scientific understanding will be possible until we understand our own role in that understanding. Indeed, that point may already be here.

I think we are very, very close to that point.

AriAstronomer
2010-Jun-24, 12:15 AM
What's more, ontological language in science is both routine and useful, so finding the most facile and appropriate philosophical stance does impact on the functioning of science. It also informs the process that we all hope science is engaged in: beyond just making correct predictions, it is bringing us closer to understanding our reality. But if that means understanding our role in how we form that understanding, then so be it. Personally, I think that at some point, we will inevitably hit a brick wall where no further advancement of scientific understanding will be possible until we understand our own role in that understanding. Indeed, that point may already be here.

I think it is very important to realize the reason we engage in science in the first place - to wonder, and find out about our universe. To do so requires abstract thought. Many people forget this, and the 'shut-up and calculate' people seem to have gotten into physics for the wrong reason, and should have perhaps done engineering instead. Although it's important to stress that everything should remain systematic, and arguing over whether our reality is that of existentialism (I am the center of the universe and everyone else is my imagination), or we have no important role in the universe (the flower would still be red with or without my presence) is an unknowable answer, since one cannot observe something without changing it. Although these are very interesting ideas, and I personally enjoy talking about them, they are also unknowable (until possibly after you die, depending on what you believe), and can simply drive you insane trying to find an answer. Anyone who tries to convince you otherwise is a fool, and fall in the same category as the religious fanatics telling you they have PROOF of God's existence.
You could even extend this argument to observation from person to person. How do you REALLY know that the red that I see is the red that you see? You point to the flower and say red, and I nod and understand, but maybe I'm seeing some off colour, or some other whacky colour entirely? Or when you say you are frustrated, and I tell you I know how you feel, how do you really know? I may observe your symptoms of frustration and conclude you are feeling the same as me, but conscious observation always includes bias, and based on your personal experiences as a human, you are always likely to attach some error to your observation. These are unknowable things, and to talk about them in a physics discussion is entertaining, but also a bit odd. I'm actually surprised no 'shutup and calculate' people have ripped this thread apart yet.

Maybe we should just find aliens already, and ask THEM what colour the flower is :P.

Len Moran
2010-Jun-24, 07:26 AM
These are unknowable things, and to talk about them in a physics discussion is entertaining, but also a bit odd. I'm actually surprised no 'shutup and calculate' people have ripped this thread apart yet.



I’m not sure that you are perhaps quite aware of the context in which this discussion takes place, so perhaps I can clarify.

The purpose of any flavour of realism is to establish the limits (or not) of the strict scientific method in terms of its applicability to ontological questions. To establish what within science we consider is actually scientific knowledge, scientific enquiry and philosophical enquiry is the real and important purpose of threads like these. The shut up and calculate people as you describe them I think only exist in minority of scientists. Most scientists would like to think that their science is applicable to ontology in a very scientific sense. The purpose of threads like these is to establish to what extent, if any, the scientific method is applicable to ontology.

In a sense, you might actually describe my scientific stance (in part) as a shut up and calculate one for I consider the scientific method to consist of the construction of mathematical predictive models and the subsequent experimental validation of those models. I consider the descriptive elements of those models to be somewhat unreliable and often change from one generation to the next. But the predictive, experimentally verified mathematical models are for ever valid within the domain of their applicability. For me, this method and the amazing and powerful outcomes it gives us is the hall mark of sentient beings. But those outcomes at all times (from my philosophical perspective of open realism) consist of investigations into nature that cannot be divorced at all from our fundamental involvement as sentient beings.

From this perspective, when we wish to consider ontological questions in terms of those models derived through the strict scientific method, the nature of the enquiry changes, it becomes a philosophical enquiry, fed by scientific enquiry (which involves experimentally unverified models), scientific knowledge (which consists of experimentally verified models) and philosophical and scientific speculation.

Ken G
2010-Jun-24, 11:00 AM
I think it is very important to realize the reason we engage in science in the first place - to wonder, and find out about our universe. To do so requires abstract thought. Many people forget this, and the 'shut-up and calculate' people seem to have gotten into physics for the wrong reason, and should have perhaps done engineering instead.I agree, and that's why I've never actually known anyone who claims allegiance to the "shut up and calculate" school to actually abide by that doctrine. David Mermin coined the phrase, but he never meant it to apply to himself, as he has a longstanding interest in pedagogy. Others have used the term as a possible approach, but no one seems to actually make it their own approach. It is essentially a philosophy that can be labeled but does not actually exist.

Although these are very interesting ideas, and I personally enjoy talking about them, they are also unknowable (until possibly after you die, depending on what you believe), and can simply drive you insane trying to find an answer.Recognizing that they are unknowable is much of the point of representative realism. It is exactly the stance that allows one to be a realist (handy in science), without ignoring certain facts (such as the unknowability of which you speak). In short, it is a means for distinguishing what is knowable (the efficacy of a representation) from what isn't (the reality that is being represented), without sacrificing realism in the process.


These are unknowable things, and to talk about them in a physics discussion is entertaining, but also a bit odd. I'm actually surprised no 'shutup and calculate' people have ripped this thread apart yet.That doesn't happen because, as I mentioned, that philosophy simply doesn't exist except in people who are rather deeply in denial about their own beliefs-- those "engineers" you mentioned. Indeed, the purpose of a forum like this is itself a rejection of the importance of "shutting up and calculating," and all participants have already eschewed that stance. We would quickly notice that anyone attempting to do what you say, to "rip this thread apart" on the grounds that it isn't "shutting up" enough, would be including no calculations in their argument-- only a whole bunch of not shutting up.

AriAstronomer
2010-Jun-25, 12:42 PM
Indeed, the purpose of a forum like this is itself a rejection of the importance of "shutting up and calculating," and all participants have already eschewed that stance. We would quickly notice that anyone attempting to do what you say, to "rip this thread apart" on the grounds that it isn't "shutting up" enough, would be including no calculations in their argument-- only a whole bunch of not shutting up.

Bravo. I suppose I am still a bit new to this forum still, and most of the questions I have encountered so far have been very physical and concrete (i.e. a clear answer to point to) vs. abstract, and more along the lines of discussion. I'm glad that this forum can be such a valuable resource for these kinds of things. Many times I have questions such as these, and have no one to provide opinions on the matter.
Cheers.

Ken G
2010-Jun-25, 12:53 PM
I agree, it's a great place to mull over science-inspired questions that you won't find at the end of the chapter in a physics textbook.

kevin1981
2010-Aug-06, 05:55 PM
I have reread this thread and it is very interesting. There are some deep conversations about the nature of reality. But as i understand it, unless we can take ourselves outside of it and look objectively which we can not do, we will probably never get a fully satisfied answer. Now i understand why this is philosophy !

I have just been learning about quantum decoherence, and know that this is fairly important, when discussing the fundamental nature of reality. My question is this;

As i understand it, quantum coherence does not last very long due to interactions with other quanta, thus, collapsing wavefunctions. So it can be argued that space and time and the macro world do not exist at a fundamental level. However, it can only not exist for a short amount of time due to decoherence.

Take it easy on me, but what are your thoughts on this?

Ken G
2010-Aug-06, 06:34 PM
But as i understand it, unless we can take ourselves outside of it and look objectively which we can not do, we will probably never get a fully satisfied answer. Now i understand why this is philosophy !Right, it is very hard to answer questions definitively in philosophy, instead, the goal is to understand the connections between the various answers-- which answers are mutually compatible? Is there a "suite of answers" you can consistently adopt that works for you? This is the goal of philosophy-- it is personal, but it is subject to the rules of logic and evidence. With a healthy does of rhetoric, of course.


As i understand it, quantum coherence does not last very long due to interactions with other quanta, thus, collapsing wavefunctions.It can only last a long time in very isolated systems. In principle, for example, the CMB has lasted in a state of quantum coherence for 13.7 billion years, so it's not just about time.


So it can be argued that space and time and the macro world do not exist at a fundamental level. However, it can only not exist for a short amount of time due to decoherence. Right, or put differently, our approximate notions become more and more usably precise over timescales that may seem very short to us, but seem very long to an atom. (By which I mean, an atom can undergo a very large number, perhaps thousands or millions, of coherent oscillations before something happens that decoheres it.)

kevin1981
2010-Aug-06, 07:13 PM
It can only last a long time in very isolated systems. In principle, for example, the CMB has lasted in a state of quantum coherence for 13.7 billion years, so it's not just about time.

Is that why it is uniformly spread in all directions throughout space, because it has'nt decohered. I guess in space there is nothing to interfere with it?


Right, or put differently, our approximate notions become more and more usably precise over timescales that may seem very short to us, but seem very long to an atom. (By which I mean, an atom can undergo a very large number, perhaps thousands or millions, of coherent oscillations before something happens that decoheres it.)

When you say "oscillations", do you mean that is takes all possible states millions of times?

Ken, would it be right to say that, space and time are not fundamental, but whatever the initial fundamental state is, it does not last very long.(at least to us humans)