The most confusing and baffling in science? (QuantumMechanics\Double Slit experiment)

[lajoswinkler]

In that simplified and limited picture: No, that would be impossible.

Steven Mading was complaining about oversimplification. Sorry to break it to you, but the full picture or any reasonable approximation requires knowledge of Hilbert spaces, differential equations and, ideally, the Hamiltonian formulation of classical mechanics. If you know those, the principles of QM can be taught in maybe an hour. And pretty much every worker in the field will be able to give you that lecture, many of them without preparation. If you don't have that background, simplifications, analogies and baffling results are all your teacher can work with, and in the case of QM, that will not even get you to the point where you can ask interesting questions. They'll just point to the holes in the simplification most of the time.

The only way to simplify QM is to go finite dimensional. If you understand basic probability and complex numbers and linear algebra, I could write a simple "Over here are classical dymanics. Over there in somewhat similar structure, QM." cheat sheet kind of thing.

Not spreading disinformation that sentient beings are changing the outcomes of experiments by "mind rays" is enough. That's what bothers people.

[Duxwing]

Frankly, I think unrestrained scientism corrodes our society much more than anything else. You don't have to go as far as electrons being sentient beings. By replacing the cartesian metaphysical premises of modern science with thomism you can simply say that subatomic particles exist as pure potency, and gain act during the interaction. The apparatus obviously has act gained from its constructor, who is the ultimate observer. Simple as that.

Recommended reading: anything by Wolfgang Smith.

If "replacing the cartesian metaphysical premises of modern science with thomism" causes absurd conclusions, then that replacement is absurd.

Intelligent design is ultimately a philosophical problem regarding final causes

Intelligent design is a discredted solution to the problem of the initial cause. The current solution is that what we know as the universe began about 13.7e9 years ago, and that if we later find that something earlier existed, then we'll think about it.

and I don't see how taking either side on that makes one a crackpot. In the end of the line, the choice is between the preferred frame of geocentrism or Dark-Matter, and the degree of crackpotness of either one is merely cultural.

Taking the ID side makes one a crackpot because dark matter is hypothetical matter that could explain observed galaxy structure whereas Intelligent design is myth. Furthermore, you're arguing from incredulity and planting a red herring because you have not argued against Dark Matter.

-Duxwing

Edited February 2, 2014 by Duxwing

[lodestar]

Yes, claiming something is mysterious and beyond mere mortals' comprehension is... harmful. But it's also not simple.

There's no mystery on the "how", but there's plenty of mystery on the "why". I think there's a lot of confusion between the two, which leads some to believe it's all clear and experts claim it's mysterious to make it sound more important, and on the other hand, there are those who believe it's incredibly complicated.

The fact that experts of the field have been arguing since a century over the fundamentals should be a small hint Well, the fact that the more advanced and amazing experiments only became possible in the last 30 years or so also has something to do with it.

I think the problem is that among the experts there are many scientific geniuses, but very few of them were skilled philosophers, and the main problem seems to be a philosophical one, a failed ontology. In the end of the day, the whole problem is that we still don't have a definitive answer to why the state vector is collapsed by the act of measurement, and that's an unsolvable problem under the cartesian dualism adopted. You can't solve the problem by staying strictly within the domain of the res extensa, as we do with classical mechanics, simply because there's an irrevocable link with the res cogitas in the observed phenomena.

Quantum phenomena become incredibly clear when you throw away the cartesianism and go back to aristotelian metaphysics, but unfortunately, that's something most physicists simply don't know how to do. Hell, most physicists don't even know how to recognize the problem! Seriously, it's almost ridiculous how Stephen Hawking claims on the first page of his The Grand Design that philosophy is dead, while he spends the rest of the book struggling with a metaphysical problem, trying to solve it with physics, and ultimately failing and engaging in a rhetorical attempt to convince the reader that reality itself is confusing.

Heisenberg himself hinted how the superposition states could be likened to aristotelian potency and the theory of forms. Wolfgang Smith suggests how to solve the problem with a thomist interpretation in The Quantum Enigma, and I think he has the best shot so far. Ian J. Thompson also tries to do it with a neo-aristotelian metaphysics in Philosophy of Nature and Quantum Reality, but I haven't read it yet.

[lodestar]

If "replacing the cartesian metaphysical premises of modern science with thomism" causes absurd conclusions, then that replacement is absurd.

But it doesn't, so what you said doesn't make sense.

Intelligent design is a discredted solution to the problem of the initial cause.

That's certainly the most popular conception, but where it bears on the matter here (which is, whether Wolfgang Smith defending it makes him a crackpot), Intelligent design is ultimately linked with the problem of whether final causes exist in reality or not. Science doesn't deal with final causes. Period. To say Intelligent Design is a discredited solution to the problem of the initial cause in scientific grounds doesn't make sense, because Intelligent Design would assume the initial cosmogenic act had a final cause, and you can't deal with that on scientific grounds. Since Wolfgang Smith is proposing a thomist interpretation of quantum phenomena, he can't have thomism without final causes, so a final cause on whatever was the initial cause is automatic, hence, Intelligent Design.

The current solution is that what we know as the universe began about 13.7e9 years ago, and that if we later find that something earlier existed, then we'll think about it.

That's not a current solution to the objective problem, but to the conceptual problem, within the paradigm adopted. If you waive any of the assumptions of that paradigm, like the most obvious, the assumption of the Cosmological Principle, you can scrap all that and start from scratch. Sorry buddy, but in the end of the day, we actually know very, very little about the universe, and it's not hard at all for everything we think we know to be wrong if a few faith based assumptions are wrong.

Taking the ID side makes one a crackpot because dark matter is hypothetical matter that could explain observed galaxy structure whereas Intelligent design is myth.

Dark Matter is a fudge factor introduced to make the field equations work with the other assumptions and the chosen interpretation of observations. It's as simple as that.

Strictly speaking, Intelligent design can be a myth in a cosmogeny context, in that the cosmogenic act can't be described in any other form but a myth, but that's not the context here, and I think you mean myth in the colloquial sense, which also doesn't make sense here.

Furthermore, you're arguing from incredulity and planting a red herring because you have not argued against Dark Matter.

I did. I said Dark Matter actually can be equally used as a reductio ad absurdum argument. Frankly, there's no better argument than that, since it's purely analytical. It simply can't be refuted. You can only say that despite that, you still believe that this make-believe matter exists somewhere, somehow, it's just a matter of time for it to be found. If that's the case, fine, but don't come to me saying I'm a crackpot because I chose to believe the opposite.

Edited February 2, 2014 by lodestar

[Duxwing]

But it doesn't, so what you said doesn't make sense.

I think that I misunderstood your initial point: do you believe that "pure potency" is not an absurd conclusion?

That's certainly the most popular conception, but where it bears on the matter here (which is, whether Wolfgang Smith defending it makes him a crackpot), Intelligent design is ultimately linked with the problem of whether final causes exist in reality or not. Science doesn't deal with final causes. Period. To say Intelligent Design is a discredited solution to the problem of the initial cause in scientific grounds doesn't make sense, because Intelligent Design would assume the initial cosmogenic act had a final cause, and you can't deal with that on scientific grounds. Since Wolfgang Smith is proposing a thomist interpretation of quantum phenomena, he can't have thomism without final causes, so a final cause on whatever was the initial cause is automatic, hence, Intelligent Design.

Intelligent Design is discredited because its assumption that an intelligent designer exists is philosophically unsound because any intelligent designer is by definition supernatural and therefore incomprehensible.

That's not a current solution to the objective problem, but to the conceptual problem, within the paradigm adopted. If you waive any of the assumptions of that paradigm, like the most obvious, the assumption of the Cosmological Principle, you can scrap all that and start from scratch. Sorry buddy, but in the end of the day, we actually know very, very little about the universe, and it's not hard at all for everything we think we know to be wrong if a few faith based assumptions are wrong.

The assumptions necessary for ID are inherently faith-based because among them is the assumption of an intelligent designer, who by definition would be supernatural and therefore incomprehensible and therefore unknowable. And I agree that believing scientific theories requires faith in their assumptions, and many of these theories--e.g., Newton's Laws of Motion--have so long so very well predicted phenomena that I doubt that you would disagree with those theories.

Dark Matter is a fudge factor introduced to make the field equations work with the other assumptions and the chosen interpretation of observations. It's as simple as that.

I agree. Many budding theories have fudge factors. What is your conclusion therefrom?

Strictly speaking, Intelligent design can be a myth in a cosmogeny context, in that the cosmogenic act can't be described in any other form but a myth, but that's not the context here, and I think you mean myth in the colloquial sense, which also doesn't make sense here.

If by "myth" you mean untestable hypothesis, then intelligent design is unempirical. If we for your argument's sake momentarily abandon empiricism, then we by Occam's Razor choose the simplest hypothesis, which is that the universe simply came into being: an intelligent designer is not necessary.

I did. I said Dark Matter actually can be equally used as a reductio ad absurdum argument. Frankly, there's no better argument than that, since it's purely analytical. It simply can't be refuted. You can only say that despite that, you still believe that this make-believe matter exists somewhere, somehow, it's just a matter of time for it to be found. If that's the case, fine, but don't come to me saying I'm a crackpot because I chose to believe the opposite.

Are you from our ignorance of Dark Matter concluding that the universe was intelligently designed?

-Duxwing

[lodestar]

I think that I misunderstood your initial point: do you believe that "pure potency" is not an absurd conclusion?

If that sounds absurd to you, you probably don't understand what it means. Read some introduction to Aristotle and Thomism. Edward Feser has some very didactic introductions for casual readers.

Intelligent Design is discredited because its assumption that an intelligent designer exists is philosophically unsound because any intelligent designer is by definition supernatural and therefore incomprehensible.

There's nothing philosophically unsound about an intelligent designer. That statement is simply absurd, because "philosophical unsound" is almost an oxymoron. That assumes philosophical knowledge is necessarily communicable, while it's exactly the opposite, necessarily personal. Your usage of supernatural in the colloquial sense doesn't make any sense either. Even in that colloquial sense, supernatural is not synonym with unknowable. It might not be communicable knowledge, which is what set science apart from philosophy, but not unknowable.

The assumptions necessary for ID are inherently faith-based because among them is the assumption of an intelligent designer, who by definition would be supernatural and therefore incomprehensible and therefore unknowable.

The only assumption needed for ID in the context of this discussion is if whether final causes exist or not. Period. If you don't understand this, fine, but don't try to push your way into the subject thinking this is a discussion about creationism and similar quackeries.

And I agree that believing scientific theories requires faith in their assumptions, and many of these theories--e.g., Newton's Laws of Motion--have so long so very well predicted phenomena that I doubt that you would disagree with those theories.

Yep, what you just don't seem to realize is that the predictive power itself rests on the assumption that the universe will necessarily always behave in the same way. That's something we just believe, there's no way to know. There's no such thing as Laws in objective reality itself. Laws exist only in our concepts of reality, in our models.

I agree. Many budding theories have fudge factors. What is your conclusion therefrom?

When the fudge factor is introduced to salvage the theory after observations that render it invalid, I call that intellectual imposture.

If by "myth" you mean untestable hypothesis, then intelligent design is unempirical.

By myth I mean myth. If you don't know what a myth is, or you only understand the colloquial usage of myth as a popular belief, you'll have to study the subject or you really won't understand what's the point here.

Of course it is unempirical. So what? I'm not saying Intelligent Design is a scientific theory, I'm saying it's a philosophical problem.

If we for your argument's sake momentarily abandon empiricism, then we by Occam's Razor choose the simplest hypothesis, which is that the universe simply came into being: an intelligent designer is not necessary.

First of all, that's a very common misconception in popular culture. Occam's Razor doesn't mandate to choose the simplest hypothesis. It mandates to choose the hypothesis with the fewest number of assumptions.

Second, Occam's Razor is obviously just an heuristics approach to improve the likelihood of finding a solution, not an irrefutable demonstration. If it worked like you seem to imagine, I could simply argue that only mind exists, since matter is not necessary. Hell, I could argue that only my mind exists, nothing else is necessary!

Third, that objection is incredibly naive. You're using "simply" as a weasel word, not realizing that to have such an ontological leap from non-existence to existence without anything to bridge the chasm will itself demand the assumption that logic itself can be suspended for that comogeny to occur, which has nothing simple about it. That's probably the most fundamental philosophical problem. Even in scientific cosmogony, there's hardly any issue that can be solved like that by Occam's Razor, including Intelligent Design.

Finally, Occam's Razor as a methodological procedure doesn't matter in the context here, because we are dealing with the issue of how the existence of final causes affects the social acceptance of an idea, not trying to rule final causes in or out as a premise for other proposition. The context here has nothing to do with providing satisfactory scientific explanations, in which keeping only whatever you deem necessary would be a sound methodological approach. For the exact same scientific theory of the origin of the universe you can assume the universe has a final cause, and therefore anything and everything that exists within it is guided to that, or you can assume final causes don't really exist and the universe only exists as it is. This is not a scientific problem. You seem to think too scientistically to grasp what's the real issue here.

Are you from our ignorance of Dark Matter concluding that the universe was intelligently designed?

As I said, in the current state of astrophysics and cosmology, the choice is between Dark Matter or geocentrism. While geocentrism by itself doesn't mean the universe is intelligently designed, in the scientific sense, it strongly suggests our privileged position has a purpose.

Edited February 3, 2014 by lodestar

[TheDarkStar]

lodestar: While I believe in a form of ID, I disagree with your logic. Why would a lack of geocentrism mean no ID? I can't see what purpose there would be in putting the Earth in the middle of the universe. If it were like that, there would be lots of things that we can discover that we could not. It would make the universe a less interesting and amazing place, which conflicts with the idea behind ID being that the world is there for us specifically to live and to learn.

[lodestar]

lodestar: While I believe in a form of ID, I disagree with your logic. Why would a lack of geocentrism mean no ID?

I didn't said that. I said that if Earth has a privileged location, it strongly suggests it has some purpose. It doesn't affect the opposite in any way, it just isn't as strong.

I can't see what purpose there would be in putting the Earth in the middle of the universe.

That's wishful thinking. Whether you see purpose in it or not, it has nothing to do with it actually having.

If it were like that, there would be lots of things that we can discover that we could not. It would make the universe a less interesting and amazing place, which conflicts with the idea behind ID being that the world is there for us specifically to live and to learn.

That's an ideological argument, not logical or scientific. That's like Stephen Hawking saying that even though we have no scientific evidence for or against it, we should believe that redshifts are velocity shifts on grounds of modesty. One can easily claim that it makes a lot more sense that in an universe made for us to live and learn, we should be in a privileged position, and there's no way out of this conundrum other than rhetoric, meaning, who is more convincing. When the discussion gets to that ideological ground, one is free to counter that argument with anything ideological too, like religion.

You're not disagreeing with the logic, but with one of the premises. That's an entirely different thing.

[K^2]

lodestar, you understand that everything you are talking about does not meet criteria of a theory, right? As such, they do not belong in a science section. You can have a philosophical discussion on these subjects, but it doesn't belong here.

[Brotoro]

...As I said, in the current state of astrophysics and cosmology, the choice is between Dark Matter or geocentrism.

You keep using that word. I do not think it means what you think it means.

Our Galaxy rotates too rapidly to be held together by the gravitational attraction of the amount matter we can detect. Dark matter is a proposed explanation for the missing mass that would provide the extra gravitational attraction needed to keep the Galaxy together. Other explanations could be possible (such as gravity having different strengths on larger distance scales than it does on short distance scales), but the Earth being your special reference frame is not going to fix the problem.

Similarly, the motions of galaxies in the Virgo Cluster and other galactic clusters are too fast to remain gravitationally bound if the cluster only contained the matter we can see in them. And that situation wouldn't change if your chose Tau Ceti as your special reference frame.

[Z-Man]

Not spreading disinformation that sentient beings are changing the outcomes of experiments by "mind rays" is enough. That's what bothers people.

No serious QM teacher would claim the mind has the power to change the outcome. That the moment a conscious mind is influenced by the result of a measurement is the moment of the waveform collapse, however... that is a position sometimes (rarely by real experts) brought forward. It is neither useful nor sound, however (the rest of this paragraph is mostly for lodestar). It is not useful because it means you still have to do full QM calculations on your measuring apparatus and everything between it and the mind to get "correct" results. It is unsound because no experiment has ever suggested there is a bound on when the collapse is supposed to happen. There is no hint of a limit on the size of quantum systems. There is no reason to assume superpositions stop being possible at any point. They do not stop for atoms and molecules. Why should they stop for life, a brain, a planet?

The most sensible way, IMHO, to treat the collapse is this: It does not really happen, but for the purpose of easier calculation, we can pretend it happens when entanglement/decoherence has gotten so bad no future interference is to be expected. It is an approximation (the discussion when and why we can apply it is ongoing). It is perfectly all right to treat Schroedinger's cat as either* dead or alive unless you can show me a way to get a dead and alive cat state to interfere again. No need to bring the dead cat back to life, it suffices to kill the alive one to make it dead in exactly the same configuration. I will not provide you with cats.

* Well, it is dead. Suffocated. The silly physicist opening the box is half dead. What did you think the cyanide would do in hermetically sealed box?

[rdfox]

Ironically, just Friday, in my physics class, we did the early version of the double-slit experiment, the one that revealed the wave nature of light. Used it to measure the width of a human hair through the interference pattern it generated with a laser, even. Fun stuff!

As for the whole debate here, I just quote a physics professor--I think it was Stephen Hawking, but don't quote me on that--who once stated, "If you think that you understand quantum mechanics, then you can't possibly have it right." QM is some weird, weird ****, with very, VERY weird potential repercussions (ever heard of the "Many Worlds" hypothesis?), and even the physicists who've made it their life's work to study it don't FULLY understand it yet.

Personally, I find it brain-breaking that things can be particles and waves at the same time (I have a 155-165 IQ, depending on the day and who's doing the testing, but I also have an engineer's mindset), but it brings absolutely magical possibilities with it. (How about the implication that there's an alternate universe out there where I'm Superman, that there's one where the Star Trek continuity is real, and that there's one where the Kerbin system exists EXACTLY as depicted in KSP, complete with constantly-respawning Kerbals riding boomcans?)

[lodestar]

You keep using that word. I do not think it means what you think it means.

Our Galaxy rotates too rapidly to be held together by the gravitational attraction of the amount matter we can detect. Dark matter is a proposed explanation for the missing mass that would provide the extra gravitational attraction needed to keep the Galaxy together.

That only depends on which numbers you plug in the redshift formula, and those numbers are assumptions. Beyond parallax, how fast or how distant stars and galaxies are and how to scale their relative movements depends on the assumption of homogeneity and isotropy and interpreting redshifts as velocity shifts, and there's no other yardstick that doesn't end up in the exact same place. Obviously, if redshifts are not velocity shifts, then the obvious conclusion is that Earth is a privileged frame, there's no expansion, no restrictions in the time-scale, no spacial curvature, and no need for Dark Matter.

Other explanations could be possible (such as gravity having different strengths on larger distance scales than it does on short distance scales), but the Earth being your special reference frame is not going to fix the problem.

Yeah, right... and you'll just try to scrap Newton's Laws for the second time, while there's a perfect valid solution that keeps it unchanged, and its only problem is an ideological commitment to something else? Well... that's why I left physics.

Similarly, the motions of galaxies in the Virgo Cluster and other galactic clusters are too fast to remain gravitationally bound if the cluster only contained the matter we can see in them.

Yes, but their motion and how much matter they have also depends on the assumptions of homogeneity, isotropy, expansion, age of the universe, etc, etc.

And that situation wouldn't change if your chose Tau Ceti as your special reference frame.

Really? Have you been there? Or you just conclude it won't change based on the assumptions of homogeneity, isotropy, expansion, the age of the universe, etc, etc?

[lodestar]

lodestar, you understand that everything you are talking about does not meet criteria of a theory, right? As such, they do not belong in a science section. You can have a philosophical discussion on these subjects, but it doesn't belong here.

First of all, not a single word I said here isn't part of current theories.

Second of all, the forum rules say nothing about being restricted to mainstream scientific theories without any divergence being accepted. Quite the opposite. It says "all things pertaining to science and general geekdom".

Third, if I am indeed violating the forum rules and my posts don't belong here, ask for a moderator. That's what they are here for.

Finally, if my presence makes you uncomfortable in some way, just say it and we'll try to find a way to work around the problem. Acting like in a treehouse club, making arbitrary rules on the spot in an attempt to ostracize me is just silly.

Edited February 3, 2014 by lodestar

[lodestar]

No serious QM teacher would claim the mind has the power to change the outcome. That the moment a conscious mind is influenced by the result of a measurement is the moment of the waveform collapse, however... that is a position sometimes (rarely by real experts) brought forward. It is neither useful nor sound, however (the rest of this paragraph is mostly for lodestar). It is not useful because it means you still have to do full QM calculations on your measuring apparatus and everything between it and the mind to get "correct" results. It is unsound because no experiment has ever suggested there is a bound on when the collapse is supposed to happen. There is no hint of a limit on the size of quantum systems. There is no reason to assume superpositions stop being possible at any point. They do not stop for atoms and molecules. Why should they stop for life, a brain, a planet?

I don't understand how the rest of that paragraph is mostly for me if it doesn't address anything I said directed to you. It even conflicts with it, since the point is that the collapse can't be understood only within the res extensa, because you'll have to reduce the corporeal to the physical. Atoms and molecules aren't corporeal objects, they are just physical objects. They only exist in reality as corporeal objects with some form. If a superposition is merely a description of a collection of potency, it does collapse when it's actualized by a corporeal object. The actualization is a determination, which promotes a de-superposition, with gaining a substantial form.

There's no hint of a limit on the size of quantum system because the notion of a delimited quantum system itself is an artifact of the cartesian ontology. Once you scrap it, a superposition of eigenstates is no different of you having the possibilities of speaking french or german superposed and actualizing one of them at a time.

The most sensible way, IMHO, to treat the collapse is this: It does not really happen, but for the purpose of easier calculation, we can pretend it happens when entanglement/decoherence has gotten so bad no future interference is to be expected. It is an approximation (the discussion when and why we can apply it is ongoing).

That doesn't really solve the problem. Even if you decide to treat the collapse as a mathematical discontinuity of the Schrödinger evolution, the question still stands if it reflects an actual indeterminacy of nature. That's called a dogma: you stabilize an unsolved issue by means of authority, so other related discussions can evolve, at the cost of some precision.

It is perfectly all right to treat Schroedinger's cat as either* dead or alive unless you can show me a way to get a dead and alive cat state to interfere again. No need to bring the dead cat back to life, it suffices to kill the alive one to make it dead in exactly the same configuration. I will not provide you with cats.

Schrödinger's cat is dead or alive, with a given probability, statistically speaking, before you open the hatch, because the cat isn't a subcorporeal object. The cat's state vector doesn't have to be in a corresponding state, since the cat has a substantial form and, in a sense, it collapses its own state vector.

Edited February 3, 2014 by lodestar

[Brotoro]

That only depends on which numbers you plug in the redshift formula, and those numbers are assumptions. Beyond parallax, how fast or how distant stars and galaxies are and how to scale their relative movements depends on the assumption of homogeneity and isotropy and interpreting redshifts as velocity shifts, and there's no other yardstick that doesn't end up in the exact same place.

No. This is where you keep making your mistake. Measuring the distances to stars within our Galaxy does not depend on Hubble redshifts or any assumptions about the homogeneity or isotropy of the universe. Our Galaxy is gravitationally bound and is not expanding apart with the Hubble flow, so any prejudice you have against Hubble shifts doesn't enter into this problem. Also, the Virgo cluster is so close to us that this missing mass is still a problem because the Hubble correction is very small.

Also, we have a number of methods for measuring distances in our Galaxy that do NOT depend upon annular stellar parallax (in case you have some prejudice against that method for measuring distances because it doesn't fit with some concept you choose to cling to despite contrary evidence). We can measure distances using nearby moving star clusters in our galaxy because of the expansion of those clusters and the motion of the Sun (not the annual motion of the Earth around the Sun); we can measure distances using binary stars; we can measure distances using expanding supernova remnants such as the Crab Nebula; we can measure distances by looking at the luminosities of stars with the same spectral type and luminosity class. In practice, of course, we use the method of annular stellar parallax because we get higher precision from those measurements, but the other methods agree. And none of these depend on any assumptions about the homogeneity, isotropy, or value of the Hubble constant of the universe. This is in our own backyard, cosmologically speaking.

[K^2]

No serious QM teacher would claim the mind has the power to change the outcome. That the moment a conscious mind is influenced by the result of a measurement is the moment of the waveform collapse, however... that is a position sometimes (rarely by real experts) brought forward. It is neither useful nor sound, however (the rest of this paragraph is mostly for lodestar). It is not useful because it means you still have to do full QM calculations on your measuring apparatus and everything between it and the mind to get "correct" results. It is unsound because no experiment has ever suggested there is a bound on when the collapse is supposed to happen. There is no hint of a limit on the size of quantum systems. There is no reason to assume superpositions stop being possible at any point. They do not stop for atoms and molecules. Why should they stop for life, a brain, a planet?

The most sensible way, IMHO, to treat the collapse is this: It does not really happen, but for the purpose of easier calculation, we can pretend it happens when entanglement/decoherence has gotten so bad no future interference is to be expected. It is an approximation (the discussion when and why we can apply it is ongoing).

That's one of the interpretations. There are several, and they are all mathematically equivalent. The difference is primarily in what you call an observer and how strict you wish to be in switching between observers. (There are some other important differences, which you can look up.) If you want to chose just one observer for the entire system and stick with it, then you may as well assume that collapse happens when that observer interacts with the observed sub-system. That's your Copenhagen Interpretation. If you want to consider system with multiple possible observers, you start to have to worry about what happens with measurements made by different observers at different places and different times. Naturally, some interesting phenomena must take place, but there are some physical limits to how significant they are. One way to restrict this is to consider decoherence. And most statistical or ensemble interpretations will take this into account. Here, like you said, you assume the system collapsed when decoherence has taken place. Finally, you can consider the whole QM problem as a whole, without simplifying it by collapse. Then you have no choice but to look at Many Worlds Interpretation or similar. The key here is that you have to consider a global wave function, it never collapses, and any observer is always a quantum sub-system in a super-position. It has limited practical value in describing experiments, but it's the interpretation where you can intuitively see resolutions to most counterintuitive features of quantum mechanics. In MWI, you can immediately see why EPR is not a paradox, why entanglement carries no information, but you can use it for Quantum Teleportation, and even Delayed Choice Quantum Eraser doesn't seem so weird.

But the key thing to remember is that these interpretations are equivalent. There are some crazy ones out there that are almost nonsensical, but Copenhagen and MWI are equivalent on the level of theorems proving equivalence. Which is why I always recommend looking at anything "weird' in QM from perspective of these two. It gives you two diametrically opposing views on the same thing, and anything that looks unintuitive from one end is clear from the other.

[lodestar]

No. This is where you keep making your mistake. Measuring the distances to stars within our Galaxy does not depend on Hubble redshifts or any assumptions about the homogeneity or isotropy of the universe. Our Galaxy is gravitationally bound and is not expanding apart with the Hubble flow, so any prejudice you have against Hubble shifts doesn't enter into this problem.

Buddy... to quote Eddington, there are no observational facts about anything in the universe. None. Zero. All astronomical measurements, without a single exception, are nothing but measurements of the phenomena occurring in an observatory or telescope, and obviously most of them from an Earth-centered frame. All those measurements are translated into other frames and therefore to knowledge of the universe through theories, which depend on assumptions, mainly the isotropy and homogeneity of the cosmological principle, which is precisely that we're not in a privileged frame.

Think carefully about what you're saying. Without assumptions on homogeneity and isotropy, you can't even say for sure that we are in a Galaxy! We assume we are in a Galaxy because we observe that stars and planets are organized in galaxies, revolving around their core, so due to those assumptions, we conclude we must be in a galaxy like those too, and some even get pictures of galaxies they believe to be similar to the Millky Way and estimate where the Solar System would be, but that ultimately rests on a set of assumptions that can be parted with easily and other set adopted. The decision is ideological, not scientific.

Also, the Virgo cluster is so close to us that this missing mass is still a problem because the Hubble correction is very small.

And how do you calculate the mass of the Virgo cluster and compare its mass-to-light ratio to something else without assuming homogeneity and isotropy at some point?

Also, we have a number of methods for measuring distances in our Galaxy that do NOT depend upon annular stellar parallax (in case you have some prejudice against that method for measuring distances because it doesn't fit with some concept you choose to cling to despite contrary evidence).

I think you're confusing things. First of all, I'm saying parallax is the only yardstick that wouldn't depend on those assumptions, not the opposite. Second, you're the one clinging to stereotypes, assuming that if I disagree with mainstream, I must be clinging to something else. As a matter of fact, I have incredibly few convictions, and whether a particular model is valid is definitely not one of them.

We can measure distances using nearby moving star clusters in our galaxy because of the expansion of those clusters and the motion of the Sun (not the annual motion of the Earth around the Sun); we can measure distances using binary stars; we can measure distances using expanding supernova remnants such as the Crab Nebula;

Sure, you can do any of these, but it leaves you between a rock and a hard place, since the distribution of many of these is geocentrically oriented. Without solving that problem, you'd have to break isotropy anyway, but then to preserve isotropy you'd appeal to GR and, where it bears on this conversation, you're back to square zero.

we can measure distances by looking at the luminosities of stars with the same spectral type and luminosity class. In practice, of course, we use the method of annular stellar parallax because we get higher precision from those measurements, but the other methods agree. And none of these depend on any assumptions about the homogeneity, isotropy, or value of the Hubble constant of the universe. This is in our own backyard, cosmologically speaking.

Everything depends on the assumptions of homogeneity and isotropy, even on our own backyard. Without assuming that you're not in a privileged frame, you can't reach any conclusions from any observation. The game is fixed. Simple as that.

Edited February 3, 2014 by lodestar

[Z-Man]

K^2: Thanks for the elaboration, but don't bother for me I'm a studied quantum guy myself. Doesn't always show, presumably. I know there are a multitude of interpretations, but I feel I still have the right to show preferences. Born, for example? Why would I want to add and solve another equation just to get the same result? I'm a practical kind of guy. If in doubt, I choose the model/coordinate system where calculations are easiest and promote it.

I don't understand how the rest of that paragraph is mostly for me if it doesn't address anything I said directed to you.

I was referring to this earlier:

we still don't have a definitive answer to why the state vector is collapsed by the act of measurement, and that's an unsolvable problem under the cartesian dualism adopted. You can't solve the problem by staying strictly within the domain of the res extensa, as we do with classical mechanics, simply because there's an irrevocable link with the res cogitas in the observed phenomena.

Which seemed to imply you think the state vector can only collapse when res cogitas (the mind? As opposed to matter? Sorry, my philosophy speak is not up to scratch) gets involved. A view which I consider harmfully restrictive, even though it is not wrong. Anyway, I am no longer sure what you mean. You lose me right at the beginning. Reduce the corporeal to the physical? All definitions of "corporeal" I looked up sound like synonyms to "physical" to me. Is corporeal this form and matter thing from Aristotle?

If a superposition is merely a description of a collection of potency, it does collapse when it's actualized by a corporeal object. The actualization is a determination, which promotes a de-superposition, with gaining a substantial form.

OK, taking "potency" "actualized" and "substantial form" as terms defined by this sentence (happens all the time in Math. I can live with that), Why does that not happen all of the time? What stops the superposition from breaking down most of the time?

Schrödinger's cat is dead or alive, with a given probability, statistically speaking, before you open the hatch, because the cat isn't a subcorporeal object. The cat's state vector doesn't have to be in a corresponding state, since the cat has a substantial form and, in a sense, it collapses its own state vector.

(from later, because it fits here)

Aha. So how does the cat differ qualitatively (apart from having more moving parts) from a photon?

Once you scrap it, a superposition of eigenstates is no different of you having the possibilities of speaking french or german superposed and actualizing one of them at a time.

Speaking both (Well, a tiny bit of French.) And no, definitely a different thing. A quantum superposition has good chances of showing interference in the future. Pure French speaking me and pure German me would not.

That doesn't really solve the problem. Even if you decide to treat the collapse as a mathematical discontinuity of the Schrödinger evolution, the question still stands if it reflects an actual indeterminacy of nature.

No, not really. If I choose to view the collapse as an approximation, that implies I view it as not part of nature.

Regarding cosmology. So you reject Dark Matter because it is a fudge factor. Fair enough. Two extra parameters (ratio of hot/cold dark matter to regular matter) and potentially two substances of unknown properties never observed in a lab. Yes, one can have problems with that.

But you also reject isotropy. Which introduces infinitely many parameters because everything (density, expansion, temperature) is now not only a function of time, but also of space. That greatly reduces verifiability. If you allow that many parameters, you can fit your model do any observation.

And you also want to take different sources for redshift into account. Well, correct me if I am wrong, but we have observed two in fully controlled experiments. Doppler effect due to relative movement and having the radiation source lower in a gravity well. It's not Doppler, you say. Which leaves a very, very odd matter distribution and gravity field (spherically symmetric would not cut it, there is no outbound gravity field of that symmetry, at least not with regular sources). A third, hypothetical source would be varying natural 'constants', shift them around and the spectra we use for determining apparent redshift move around... but then you are fully in the "we know nothing, we can never know anything, we will never predict anything correctly, we will never explain anything" territory. Is that your point? You could have stopped at "For all I know, I am just a mind and all the rest is just illusion", then.

[Duxwing]

If that sounds absurd to you, you probably don't understand what it means. Read some introduction to Aristotle and Thomism. Edward Feser has some very didactic introductions for casual readers.

Potency is a property of something, making the pure form absurd.

There's nothing philosophically unsound about an intelligent designer. That statement is simply absurd, because "philosophical unsound" is almost an oxymoron. That assumes philosophical knowledge is necessarily communicable, while it's exactly the opposite, necessarily personal. Your usage of supernatural in the colloquial sense doesn't make any sense either. Even in that colloquial sense, supernatural is not synonym with unknowable. It might not be communicable knowledge, which is what set science apart from philosophy, but not unknowable.

You're going to solipsism.

The only assumption needed for ID in the context of this discussion is if whether final causes exist or not. Period. If you don't understand this, fine, but don't try to push your way into the subject thinking this is a discussion about creationism and similar quackeries.

From that same assumption follows the far more parsimonious hypothesis, "The universe, its own initial cause, came into being" Intelligent design and creationism are the same thing: when creationism went out of style, creationists renamed their philosophy intelligent design.

Yep, what you just don't seem to realize is that the predictive power itself rests on the assumption that the universe will necessarily always behave in the same way. That's something we just believe, there's no way to know. There's no such thing as Laws in objective reality itself. Laws exist only in our concepts of reality, in our models.

So are you abandoning empiricism?

When the fudge factor is introduced to salvage the theory after observations that render it invalid, I call that intellectual imposture.

Gravity is not fully understood.

By myth I mean myth. If you don't know what a myth is, or you only understand the colloquial usage of myth as a popular belief, you'll have to study the subject or you really won't understand what's the point here.

Now you're just arguing from authority.

Of course it is unempirical. So what? I'm not saying Intelligent Design is a scientific theory, I'm saying it's a philosophical problem.

If you're not arguing that it's scientific, then it belongs not in this forum subsection, and if it's philosophical, then your present justification most parsimoniously proves that the universe simply came into being.

First of all, that's a very common misconception in popular culture. Occam's Razor doesn't mandate to choose the simplest hypothesis. It mandates to choose the hypothesis with the fewest number of assumptions.

Intelligent Design requires more than one assumption.

Second, Occam's Razor is obviously just an heuristics approach to improve the likelihood of finding a solution, not an irrefutable demonstration. If it worked like you seem to imagine, I could simply argue that only mind exists, since matter is not necessary. Hell, I could argue that only my mind exists, nothing else is necessary!

Without evidence we have nothing but Occam's Razor whereby to make existence claims. If you want to further epistemeologically doubt, then consider the Munchausen Trilemma.

Third, that objection is incredibly naive. You're using "simply" as a weasel word, not realizing that to have such an ontological leap from non-existence to existence without anything to bridge the chasm will itself demand the assumption that logic itself can be suspended for that comogeny to occur, which has nothing simple about it. That's probably the most fundamental philosophical problem. Even in scientific cosmogony, there's hardly any issue that can be solved like that by Occam's Razor, including Intelligent Design.

The universe would simply come into being whether the designer exists or not because the designer would require supernatural means to create the universe because the universe all of reality, including the designer himself.

Finally, Occam's Razor as a methodological procedure doesn't matter in the context here, because we are dealing with the issue of how the existence of final causes affects the social acceptance of an idea, not trying to rule final causes in or out as a premise for other proposition. The context here has nothing to do with providing satisfactory scientific explanations, in which keeping only whatever you deem necessary would be a sound methodological approach. For the exact same scientific theory of the origin of the universe you can assume the universe has a final cause, and therefore anything and everything that exists within it is guided to that, or you can assume final causes don't really exist and the universe only exists as it is. This is not a scientific problem. You seem to think too scientistically to grasp what's the real issue here.

Ad hominem. No true Scotsman and Moving the Goalposts.

As I said, in the current state of astrophysics and cosmology, the choice is between Dark Matter or geocentrism. While geocentrism by itself doesn't mean the universe is intelligently designed, in the scientific sense, it strongly suggests our privileged position has a purpose.

Non-sequitur: a geocentric universe could have Dark Matter.

-Duxwing

[Skyler4856]

The electron gun is aimed generally, and the electron actually takes every possible path at the same time, we observe them taking one path through a principle called the action.

[Climberfx]

Hello my young padawans.

I see great force here, but where is enough force, is the danger to got in the Dark Side.

These divergences in opinions should not pass to disrespect. But true, to make all we think about the wonderful of our Universe.

Like we saw in "What a blip do we know", All the true from today, may the the lie from tomorrow, lets keep an open mind, just because here we are all in the grounds of Philosophy. Not Real Science, because i really don't see any real experiment, but words.

And finally, these thread make me think, and just that is a marvelous thing.

Go on, and remember, we are all watching...

[lajoswinkler]

That movie is a pile of cow poop. It was made by a cult and a scientist they've used later regret his actions.

[Climberfx]

Dr Quantum, the start Youtube link here in this thread is from there Lajoswinkler.

But i respect your opinion about it. In particular, i like it, not all perfect, but have good parts.

In the aesthetics, is to dam weak.

Edited February 4, 2014 by Climberfx

[lodestar]

I was referring to this earlier: Which seemed to imply you think the state vector can only collapse when res cogitas (the mind? As opposed to matter? Sorry, my philosophy speak is not up to scratch) gets involved. A view which I consider harmfully restrictive, even though it is not wrong. Anyway, I am no longer sure what you mean. You lose me right at the beginning. Reduce the corporeal to the physical? All definitions of "corporeal" I looked up sound like synonyms to "physical" to me. Is corporeal this form and matter thing from Aristotle?

It's not that at all. I'll try to explain, in the context of this topic. Let's say we don't apprehend reality directly through our senses, we form mental concepts that correspond to the real objects. The purpose of the scientific method is then to strip those concepts of anything that can't be described mathematically, not to know the objects in themselves, beyond our mental concepts (that's the role of philosophy, by the way). For instance, when we conceptualize an electron as a subatomic particle with negative charge, that's not all the electron is in reality, that's just all we need to describe it mathematically to understand a particular phenomenon.

For instance, think of a soda can and a piece of curtain rod, both made of aluminum. They may be made of the same atoms, have the same mass, and many other properties, but there's one fundamental difference about them that doesn't actually have physical existence, their form. The ideal form of a soda can and a piece of curtain rod can exist in our minds independently of any matter. So, we could divide reality in things that can be fully described mathematically without a residue, and things that can't be described without their forms, or in other words, without a corresponding mental concept, what Descartes called res extensae and res cogitas.

This premise of the cartesian ontology, called bifurcation by some, is one of the basic premises of modern science, although most scientists don't have the philosophical training to recognize it. For modern science, there's only the res extensae, only things that can be described mathematically without any residue, but obviously, on our day to day lives we don't even contemplate that notion. When we see a soda can or a piece or curtain rod, we don't think of them as a bunch of atoms of aluminum, we think of them as their forms.

The whole point is that a subatomic particle exists without form, it exists only within the res extensae, and the state vector collapses not when it interacts with the mind, but when it interacts with something within the res cogitans, something that can't be completely described within the res extensae, like a bubble chamber or a double slit cover and wall. This something will determine what's the substantial form the subatomic particle will acquire when one of its many potential states is actualized, something Wolfgang Smith calls vertical causality, to distinguish it from horizontal causality, the physical chain of causality. Pretty much like two vectors, vertical causality can't effect horizontal causality, but it can effect an ontological change that will then effect physical causality. The quantum phenomena are pretty intuitive and clear when you put it under these premises, something Heisenberg himself recognized but nobody paid much attention. It puzzled physicists for decades because they are trying to explain it only within the res extensae, and that's doomed to fail, because quantum phenomena ultimately bridge the gap. In a sense, they are the empirical proof that Descartes was wrong.

OK, taking "potency" "actualized" and "substantial form" as terms defined by this sentence (happens all the time in Math. I can live with that), Why does that not happen all of the time? What stops the superposition from breaking down most of the time?

OK. Crash course in Aristotelian metaphysics. Potency is the potential for some change. For instance, a bunch of clay can be molded into a brick or a vase, it has the potency to that. Act is changing an object to one of its potencies, so when you mold the bunch of clay into a brick, you're actualizing it into a brick. Substantial form is simply how matter is organized when actualized, so the bunch of clay actualized into a brick now has the substantial form of a brick.

So, a particle in a state of superposition exists only as potency, without form. The state vector is collapsed when it interacts with the measurement instrument, which has form and transfer act. What stops the superposition from breaking down most of the time is precisely that most of the time it's not being actualized by something.

Aha. So how does the cat differ qualitatively (apart from having more moving parts) from a photon?

The cat has substantial form, a photon doesn't.

And no, definitely a different thing. A quantum superposition has good chances of showing interference in the future. Pure French speaking me and pure German me would not.

Yep, but we are not talking of two pure copies of you who can speak French or German, but a single one who has potential for both, but can actualize only one at a time.

No, not really. If I choose to view the collapse as an approximation, that implies I view it as not part of nature.

Fine, but that strict determinism is a choice. It doesn't really solve the problem.

Regarding cosmology. So you reject Dark Matter because it is a fudge factor. Fair enough. Two extra parameters (ratio of hot/cold dark matter to regular matter) and potentially two substances of unknown properties never observed in a lab. Yes, one can have problems with that.

Not only because it's a fudge factor, but because it's a fudge factor adopted for ideological, not scientific reasons. When the ether was scrapped, taking with it simpler explanations for a plethora of electromagnetic phenomena, the main argument was that it was undetected or if it actually existed, it would mean Earth wasn't moving. OK, I could live with that. Years later, you have Dark Matter equally undetected, serving the exact opposite purpose of preserving the theory that solved the initial problem and scrapped the ether, and people act like it's no problem at all. Why the double standard? That's what I call imposture, and that's done for ideological motivations.

But you also reject isotropy. Which introduces infinitely many parameters because everything (density, expansion, temperature) is now not only a function of time, but also of space. That greatly reduces verifiability. If you allow that many parameters, you can fit your model do any observation.

I wouldn't say I reject isotropy, I just recognize it as a dogma, not as an observable fact. I am free to part with it if I believe it doesn't makes sense, and in many cases it doesn't.

As to introducing complexity and reducing verifiability, even though we could argue a little on that, I'd say reality is under no obligation to present itself to us in a simple intelligible way. That's our approach to understand it, assuming those properties. If the universe isn't isotropic then it isn't isotropic, and no matter how complicated it can be, assuming it is will lead to wrong results.

And you also want to take different sources for redshift into account. Well, correct me if I am wrong, but we have observed two in fully controlled experiments. Doppler effect due to relative movement and having the radiation source lower in a gravity well. It's not Doppler, you say. Which leaves a very, very odd matter distribution and gravity field (spherically symmetric would not cut it, there is no outbound gravity field of that symmetry, at least not with regular sources).

If I understand your objection correctly, the problem is that you're not taking the whole package. I wouldn't say odd because that qualifier is merely cultural, but yes, that leaves you with a very small, dense, closed and young universe, but also with the Earth in the center and the universe spinning around. Your symmetrical outbound gravity field that keeps everything from falling apart is nothing but good old centrifugal force.

Anyway, even if you interpret redshifts to be Doppler, expansion of the space itself, compton effect, or any other interpretation that escapes the problem of having to put Earth in the center, you're still left with the problem of quasar redshift distribution, that persists no matter what interpretation you choose. Even if we stick with the standard model, you still have 23760 known quasars distributed in uniform concentric shells around the Earth, and currently there's no solution to that other than admitting Earth is in a privileged frame. This is really an unsolved issue.

A third, hypothetical source would be varying natural 'constants', shift them around and the spectra we use for determining apparent redshift move around... but then you are fully in the "we know nothing, we can never know anything, we will never predict anything correctly, we will never explain anything" territory. Is that your point? You could have stopped at "For all I know, I am just a mind and all the rest is just illusion", then.

Not at all. Quite the opposite. I'm not saying that we will never predict anything correctly, I'm saying that if we can predict things correctly in many different ways, why some of them are rejected on ideological basis if science is supposed to abstain from that? The moment I realized that is when my interested shift from physics to philosophy and researching scientific imposture became a hobby.

Edited February 4, 2014 by lodestar