Can I end post-modern era?

[arthwollipot]

Originally Posted by LarryS

Odd that a philosophy forum would so consistently descend into philosophy

Yeah, funny how that works.

[IanS]

Originally Posted by arthwollipot

I wouldn't use the word "wrong" like this. Newtonian gravity is extremely accurate at most scales. We can fling spacecraft across the solar system and have them hit their mark, using only Newtonian physics. There are a few arenas in which it gets less accurate, and then you use Einstein to modify, not replace, Newtonian physics.

Newton wasn't wrong - he just wasn't as close as Einstein.

Originally Posted by Darat

Which does mean he was wrong! As a model of the universe/reality it is wrong, albeit it is a very useful model where it works.

Originally Posted by arthwollipot

Again, I wouldn't use that word here.

I'm with Arthwollipot and Roboramma on this one.

Darat - Newton was only "wrong" in the sense that 250 years after Newton, with the discovery of QM, we found that (if QM is correct ... and we think it is) then there is no such thing as absolutes such as "wrong" or "right" in the sense of 100% factual accuracy or "certainty" for the bahaviour of what we describe as material existing real things in the universe around us.

Einstein and Relativity are also "wrong" in that same sense. The outcome predicted/given by the equations of Relativity is also not 100% certain/accurate.

In Newtons time, everyone believed that if we could gather all possible relevant data about any system, then in principle at least, we could calculate 100% precisely how that system would behave. But what we discovered with QM is that, that is not correct. The best we can ever do is calculate a probability of the system behaving in any specific way.

So in that sense, I think (ie afaik), the thing that's "wrong" here, is to think (and write) about what we observe/detect as the behaviour of material "real" objects & events/processes, in terms of using absolute concepts like "wrong"!

[LarryS]

Yah like Flat Earth model is kinda wrong . . . but it works great for 99.99% of navigation . . . like going to Grandma's to play Canasta.

[Gord_in_Toronto]

Wrong spool.

[Gord_in_Toronto]

Originally Posted by LarryS

Yah like Flat Earth model is kinda wrong . . . but it works great for 99.99% of navigation . . . like going to Grandma's to play Canasta.

My grandma lives in Australia -- close to the Ice Barrier (qv). Fortunately she does not play canasta.

[IanS]

Originally Posted by Gord_in_Toronto

My grandma lives in Australia -- close to the Ice Barrier (qv). Fortunately she does not play canasta.

Is it very flat there, close to the ice barrier?

Good job she stays clear of canasta, b/cos I heard that does make people fall off the edge.

And also, even if it is all flat, people do still sometimes fall over, I have seen that! Still, I suppose that's gravity for you huh?

[LarryS]

Originally Posted by Gord_in_Toronto

My grandma lives in Australia -- close to the Ice Barrier (qv). Fortunately she does not play canasta.

Good thing cuz you could save time fashioning a great circle route then lose that time playing canasta. BTW my grandma is long dead and loved Canasta

[Rystiya]

Originally Posted by IanS

OK, well most of the above is not anything I'd be particularly dismissive of. So that's fine.

Though re. that first highlight - what are the limitations of science? What do you think is inherently somehow beyond the possibility of being investigated or understood through a scientific approach? Because I can't actually think of anything.

Of course there are countless situations where using some formal apparatus of science would be hopelessly inefficient (as well as probably not necessary).

For example it's generally much easier & quicker to learn how to play a musical instrument via all the traditional methods of teaching music. But if you really wanted to do it, then there is nothing to stop you studying all sorts of aspects of sound waves and how various instruments make different sounds. And you could certainly also use science to decide why certain teaching methods may be more successful than others, and to find out why some people seem to do better, or others seemingly not so well etc.

This is a question that's been raised here many times before of course, and a lot people here (not just me) have expressed that view, where they don't really see why in principle science could not actually be used to learn more about anything ...

... so what are these things that are said to be inherently beyond the reach, realm or understanding of science?

On the second highlight - I think everyone here agrees that we do of course have experiences. None of your opponents here are arguing against that. The objection that you are encountering, is that I and others are still waiting to hear a plausible explanation of how we have experiences of such things without the real-world objects existing, such as a real-world brain & sensory system with which to form any such "experiences" in the first place.

And lastly ; I don't particularly "love science" ... but what I think about it is simply that it's "proved" itself vastly more successful than any other so-called "way of knowing" such as philosophy or religion. So that, if anyone truly wanted to understand more about the world we live in, and about what is likely to be true vs untrue in this world/universe, then science has shown the credentials to do just that. Whereas those other approaches have not only shown a huge lack of any such credentials, but where they have in fact been shown to be almost always completely & badly wrong in all the power and capability that they had originally claimed for themselves. On which basis I think it's only fair (essential, actually) to give science it's fair due for that (and conversly only fair to reject those other approaches as either very weak indeed, or more often frankly just dangerous untrue nonsense).

'What do you think is inherently somehow beyond the possibility of being investigated or understood through a scientific approach? ' Science can't tell whether everything you know is just an illusion. Which is quite obvious. Since science is all based on analysing our experiences (that include all we feel and observe), if our experiences are just illusion, science is screwed.

"I and others are still waiting to hear a plausible explanation of how we have experiences of such things without the real-world objects existing". As I have said, perhaps you are a dark god dreaming about this world. Obviously you don't have a physical brain in this case. Your mind, body, society, continent, everything is just your imagination. That's not very likely, but nevertheless possible.

[Rystiya]

Originally Posted by jrhowell

Human experiences are made of interactions between neurons. Having experiences is a process, not a physical construct.

Your experiences indicates that the contents of your experiences are related to activities in your brain. That's true. But does that imply that the former is generated by the latter? How can physical materials generate none-physical experiences?

[Roboramma]

Originally Posted by Rystiya

Note knowledge on patterns are gained by observing and concluding experiences, hence the former is less real.

The highlighted doesn't follow.

Quote:

Patterns themselves are real, yet you can't be absolutely sure on what is their cause and implications.

As I said, we can't be absolutely certain of anything. What's important is degree of credence, not absolutely certainty.

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Your example might not be accurate. Words are made of letters, yet nothing is made of experiences and experiences are made of nothing, as far as we know.

No. As far as we know, experiences are a type of information processing.

[Darat]

Originally Posted by Rystiya

'What do you think is inherently somehow beyond the possibility of being investigated or understood through a scientific approach? ' Science can't tell whether everything you know is just an illusion. Which is quite obvious. Since science is all based on analysing our experiences (that include all we feel and observe), if our experiences are just illusion, science is screwed.

"I and others are still waiting to hear a plausible explanation of how we have experiences of such things without the real-world objects existing". As I have said, perhaps you are a dark god dreaming about this world. Obviously you don't have a physical brain in this case. Your mind, body, society, continent, everything is just your imagination. That's not very likely, but nevertheless possible.

Actually there are some speculative ideas that indicate we could actually tell if we were in a simulation or not. (Precision and chaotic systems are some of the ones I’ve read.)

That aside - I can demonstrate to you that your experiences arise from chemical and physical reactions mainly located in your nervous system and brain, whether those are being simulated or not that remains the case.

[Darat]

Originally Posted by Rystiya

Your experiences indicates that the contents of your experiences are related to activities in your brain. That's true. But does that imply that the former is generated by the latter? How can physical materials generate none-physical experiences?

I suspect that you are using a specific definition for “none-physical” so may be a good idea for you to clear that up.

But assuming you mean what I usually understand people to mean by “none-physical”, its a very poor argument since it means you deny any process happens. For instance for you that would mean no one ever “runs” anywhere as a run becomes “none-physical” as a run is a process. In other words when I ask you to point out “where” the “none-physical” run “is” you can’t therefore according to you no one can run. It’s like claiming we can never have tortoise kebabs because you can never catch a tortoise!

Lots of things we deal with every day are “none-physical” but they still certainly exist, and your experiences actually aren’t one of those non-physical things, as I said we know what your experiences are. - they are chemical and physical reactions in your nervous system and brain. We can demonstrate this is so many ways, alter the chemical mixture in your brain and we can create at will specific experiences, we can do the same by making physical alterations to your brain, we can stop you experiencing anything, we can even let you experience things that you won’t even know you experienced afterwards!

[IanS]

Originally Posted by Rystiya

'What do you think is inherently somehow beyond the possibility of being investigated or understood through a scientific approach? ' Science can't tell whether everything you know is just an illusion. Which is quite obvious. Since science is all based on analysing our experiences (that include all we feel and observe), if our experiences are just illusion, science is screwed.

Not at all. Science has concluded that it's not an illusion. That's why scientists do all the work that they have done. And that's how & why we have learned so much, and improved the world so much for everyone.

What you seem to mean (again) is that science cannot actually "Prove" that what we detect is real (ie not all just a non-existent illusion), ie a literal proof as people think we get in maths (though in fact, afaik, even in maths, although we call the equations "proofs", they are in fact not 100% certain proofs! ... in every case in maths, where we are dealing with what we detect as real-world objects and events, the mathematical proof starts by requiring some sort of un-proven assumption)...

... but the point is that whilst science cannot provide you with literal certainty, ie a "proof", neither can any other way of "knowing". On the contrary, what the science shows, is that, that sort of "proof" is probably impossible for anything in a quantum universe such as ours.

But to repeat (so that you don't miss the essential point) - science most definitely can tell us, and definitely does tell us, that the universe we detect is real. And it has described every aspect of that universe (vastly beyond even the wildest imagination of people such as yourself who are outside of core science research), in detail so mind bogglingly precise that people such as yourself (again) outside of core research have absolutely no conception of just how deep and profound that success has become ... but what science has also found is that it's probably not possible to ever provide 100% proven certainty in a world where the fundamental building blocks are quantum processes ... instead the closest it's ever possible to get (by any method) is to calculate an accurate probability.

In asking for certainty (ie literally proof, or facts etc.), what you are asking for, is for us to live in a different universe where quantum process have no existence.

Originally Posted by Rystiya

"I and others are still waiting to hear a plausible explanation of how we have experiences of such things without the real-world objects existing". As I have said, perhaps you are a dark god dreaming about this world. Obviously you don't have a physical brain in this case. Your mind, body, society, continent, everything is just your imagination. That's not very likely, but nevertheless possible.

It's no good you just saying "perhaps you are a dark god dreaming about this world", if you claim that may be true (as you just have), then you have to show how that would be possible ...

... can you show how we might only be a "dreaming god", ie a disembodied mind that needs no brain or body?

To repeat again, in case you miss that point - how would it be possible for any such disembodied god to exist? You have to show that if you say it's possible … how is it possible?.

[Roboramma]

Originally Posted by Darat

Which does mean he was wrong! As a model of the universe/reality it is wrong, albeit it is a very useful model where it works.

I'm on Darat's side on this one.

Newtonian physics makes a specific prediction about, say, the orbit of Mercury, or where we'll see certain stars that are near the Sun in the sky when an eclipse allows us to look at them. It turns out those predictions are wrong.

And the reason is that reality doesn't actually conform to the underlying description supplied by Newtonian physics.

However, some people will misinterpret this. See my sig.

Which is why I also agree with Arthwollipot when he says this:

Quote:

Darat and I aren't very far from being in complete agreement, apart from how that word is used.

[Myriad]

In what way or under what circumstances would "perhaps you are a dark god dreaming about this world" be a more useful model for understanding and negotiating the world than a materialistic one? Or for that matter, more useful than any number of religions and other philosophies?

Someone facing misfortune and adversity would in no way be comforted by believing that as a dreaming dark god, they were somehow responsible for it all.

Someone lacking empathy for others would in no way be motivated to greater social responsibility by the notion they were a dark god dreaming the world. Quite the contrary! In that case why not dream of plunder and pleasure?

People facing difficult decisions? Coping with unwanted changes in their lives? Planning for uncertain futures? Dealing with guilt? Family issues? Learning? Bereavement? I can't think of any situations where "I'm a dark god dreaming the world" would do anyone any good. Acknowledging that the world is (a) real and (b) mostly not under ones own control is a much better starting point for solving and coping with problems.

[IanS]

Originally Posted by Roboramma

I'm on Darat's side on this one.

Newtonian physics makes a specific prediction about, say, the orbit of Mercury, or where we'll see certain stars that are near the Sun in the sky when an eclipse allows us to look at them. It turns out those predictions are wrong.

And the reason is that reality doesn't actually conform to the underlying description supplied by Newtonian physics.

However, some people will misinterpret this. See my sig.

Which is why I also agree with Arthwollipot when he says this:

Oh, OK, Fair enough (sorry if I misrepresented your view on that).

But how big is the error for, say, the precession of Mercury?

Afaik (and I've never needed to check any of this before), most of the earlier space missions used Newtons laws to calculate all the necessary data. Ie, they were not (afaik) using or needing Relativity ... the accuracy from Newton alone was sufficient.

So, if that's the case, then I think it's unreasonable to say that Newtons equations are "wrong", when afaik Relativity will also not be 100% accurate. AFAIK, it's simply the case that Relativity is a closer approximation than Newtons equations. That is, neither method will give 100% certain accuracy in all situations.

As I said above - I think that if you wanted to say that Newton was "wrong", then it's fairer to say that what he was wrong about, was to believe that his equations would always provide 100% accuracy. But Newton lived at a time when everyone did believe that 100% accuracy was always attainable. Now, we know that 100% certainty like that is probably impossible in a quantum universe. And likewise, afaik, Relativity will not give 100% perfection either ... so you have to say that was "wrong" too ...

... you'd end up having to say that everything & everyone was/is wrong!

[Darat]

Originally Posted by IanS

…snip…

... you'd end up having to say that everything was wrong!

Yep.

A 100% opinion from my nether regions - I don’t think we will ever have a theory of everything. The universe IS the theory of everything. I think we will end up with “merely” better and better patchworks of “laws”, “theories” and so on that will let us do the predictions we require for anything, but there will be no great unified theory.

And I think it is right that we always regard the models that arise from theories (like Newton’s) as being wrong as these models do not match up with the observable data.

There is nothing wrong with them being wrong, as I’ve repeatedly said they are very useful as long as we use them only where they apply, we need to know they are wrong so we don’t misuse them. I’d say not regarding them as being wrong is to do what religions do with their models i.e. their models are right even if they contradict observable data.

Perhaps it is my religious upbringing that makes me want to avoid hubris!

[Roboramma]

Originally Posted by IanS

Oh, OK, Fair enough (sorry if I misrepresented your view on that).

But how big is the error for, say, the precession of Mercury?

Afaik (and I've never needed to check any of this before), most of the earlier space missions used Newtons laws to calculate all the necessary data. Ie, they were not (afaik) using or needing Relativity ... the accuracy from Newton alone was sufficient.

Absolutely.

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So, if that's the case, then I think it's unreasonable to say that Newtons equations are "wrong", when afaik Relativity will also not be 100% accurate.

We've tested relativity in many many ways and so far it's always been consistent with experiment, to within the accuracy of our measurements.

It may turn out that General Relativity is wrong too (it probably is, though it's pretty damn close), but that doesn't mean Newton's laws are right about everything.

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AFAIK, it's simply the case that Relativity is a closer approximation than Newtons equations. That is, neither method will give 100% certain accuracy in all situations.

That's probably true, but we haven't actually reached any place where relativity fails. We don't really know what it says about the smallest scales, but we also can't really probe those scales experimentally yet (the energies are too high if you want to try to probe the region where gravity actually matters). Similarly it will probably fail when it comes to black holes, but everything we've been able to observe so far is entirely consistent with the predictions of GR.

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As I said above - I think that if you wanted to say that Newton was "wrong", then it's fairer to say that what he was wrong about, was to believe that his equations would always provide 100% accuracy. But Newton lived at a time when everyone did believe that 100% accuracy was always attainable. Now, we know that 100% certainty like that is probably impossible in a quantum universe. And likewise, afaik, Relativity will not give 100% perfection either ... so you have to say that was "wrong" too ...

QM doesn't suggest that we can't have laws that are models of the underlying reality. The equations of quantum mechanics are the most precisely tested theory we've ever had and they are in agreement with every experiment ever done.

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... you'd end up having to say that everything & everyone was/is wrong!

The universe is behaving in some way. Newton's view (and that of classical physicists who came after him and developed the framework of classical physics) is very close to that underlying reality in that if you take the limit where the speed of light is infinite and plank's constant is zero you basically get classical physics. So the degree to which the real world differs from classical physics is close to just how far those values are away from those idealizations.

Maybe I'm expecting too much. If the goal is only to have models that can be used to make predictions about experiments, then models aren't wrong, they're just more or less accurate. But if the goal is a description of the underlying reality of the world, and I think many physicists, past and present, really are working with the goal in mind, then some models are wrong and there is one, as yet to be fully developed, model which is correct. We may not know it, but it is knowable (though I suppose it may not be discoverable).

[IanS]

Originally Posted by Darat

Yep.

A 100% opinion from my nether regions - I don’t think we will ever have a theory of everything. The universe IS the theory of everything. I think we will end up with “merely” better and better patchworks of “laws”, “theories” and so on that will let us do the predictions we require for anything, but there will be no great unified theory.

And I think it is right that we always regard the models that arise from theories (like Newton’s) as being wrong as these models do not match up with the observable data.

There is nothing wrong with them being wrong, as I’ve repeatedly said they are very useful as long as we use them only where they apply, we need to know they are wrong so we don’t misuse them. I’d say not regarding them as being wrong is to do what religions do with their models i.e. their models are right even if they contradict observable data.

Perhaps it is my religious upbringing that makes me want to avoid hubris!

OK. Well I think we each know what the other means. And it's not a big deal (ie whether we prefer to say "wrong" or to tone that down a bit ... eg just as a matter of respect for how considerable Newtons contribution was).

On the "ToE" - I'm more optimistic. I think QFT is very close now, and I think what will happen with that, is that a ToE will probably turn out to be "more of the same", ie where we are still bound by a probabilistic quantum field description of the universe.

In the same way, and for the same reasons or sentiments, I'm not keen on saying that (for example) “the laws of physics break down at the point of the Big Bang”. I think that's probably too simplistic as a view of what happens at the moment of the BB, and I think it's probably dismissing all of quantum physics (since that's the branch of physics that we are mostly relying upon at the point of the BB) too easily, and doing that too much like you might expect from people who in my opinion do not have sufficient respect for the enormous achievement which science has made with (in that example) quantum field theory.

We could go into that, ie why I think it's similarly a mistake or unreasonable, and perhaps misleading for the vast majority of non-specialists, if we dismiss really crucial entire areas of science like that by just saying “oh physics all breaks down”, or as in the context we had for that chat about Newton, saying “our physics is all wrong (or useless etc.) at that point”.

That's not really a field of research that many of us have ever worked in. Not even those amongst us who have written doctorate theses about branches of QM. And certainly I'd need several years of study and revision before I'd like to venture stronger opinions on things like claims of “physics breaking down” under conditions that we think are most likely at the point of the BB. But anyway … the point is that, for such reasons, I'm just generally reticent about making sweeping or broad statements about major parts of science actually being anything as simple as just plain "wrong”.

[IanS]

OK, all the following is just general friendly chat, and nothing aat all rgumentative or confrontational -

Originally Posted by Roboramma

Absolutely.

We've tested relativity in many many ways and so far it's always been consistent with experiment, to within the accuracy of our measurements.


Relativity is not my field, so I could not confidently agree or disagree with what anyone says about it. But, afaik relativity starts to give more-&-more improbable answers the closer we approach to things on subatomic scales. But afaik, it's not just scales as tiny as that, it's also inaccurate or "faulty" as we approach what we think is the very highly condensed state of the Big Bang ... but although that is often described as all matter and space shrunk down the smallest sub-atomic scale, afaik it would not have to be anywhere near that small ... it could be much larger than that, say the size of a golf ball, or a football, or even the size of the Earth, when extreme ("extreme" compared to our experiences on Earth now 1.8 billion years after the BB) quantum forces and extreme changes to gravity begin to dominate.

You might say that those are very extreme conditions and not what Relativity was ever intended to explain accurately ... but that looks exactly like the same as the criticism being levelled here at Newtons theory.



It may turn out that General Relativity is wrong too (it probably is, though it's pretty damn close), but that doesn't mean Newton's laws are right about everything.


Well, as I say - I don't think any Theory can be actually "right about everything". That again is what we have learned from QM.


That's probably true, but we haven't actually reached any place where relativity fails. We don't really know what it says about the smallest scales, but we also can't really probe those scales experimentally yet (the energies are too high if you want to try to probe the region where gravity actually matters). Similarly it will probably fail when it comes to black holes, but everything we've been able to observe so far is entirely consistent with the predictions of GR.


To repeat the above - it fails when we get to the super-condensed phase of the Big Bang, doesn't it?


QM doesn't suggest that we can't have laws that are models of the underlying reality. The equations of quantum mechanics are the most precisely tested theory we've ever had and they are in agreement with every experiment ever done.


I don't think I said anything different from that, did I?


The universe is behaving in some way. Newton's view (and that of classical physicists who came after him and developed the framework of classical physics) is very close to that underlying reality in that if you take the limit where the speed of light is infinite and plank's constant is zero you basically get classical physics. So the degree to which the real world differs from classical physics is close to just how far those values are away from those idealizations.


Maybe I'm expecting too much. If the goal is only to have models that can be used to make predictions about experiments, then models aren't wrong, they're just more or less accurate. But if the goal is a description of the underlying reality of the world, and I think many physicists, past and present, really are working with the goal in mind, then some models are wrong and there is one, as yet to be fully developed, model which is correct. We may not know it, but it is knowable (though I suppose it may not be discoverable).


I don't think that was originally the "goal" in Newtons time. I think in his day everyone believed that Theories like those of Newton did predict exactly how things would behave, under all conditions throughout the universe.

But I think what we have since learned from QM, is that, that is the most we can ever hope for. I.e., if QM is correct then the best we can do is to get results that show a probability of how things will behave.

But more than that, afaik QM itself will almost certainly need to be improved/modified, both to obtain a more accurate picture of subatomic interactions generally, i.e. hence QFT replacing QM, but also to get an accurate description of what happened during and "before" the Inflationary stage of the Big Bang (that's assuming of course that (a) there was an inflationary stage more-or-less as Alan Guth and others have described it, and (b) assuming that there was in fact a BB close to what has been described).

[Roboramma]

Originally Posted by IanS

OK, all the following is just general friendly chat, and nothing aat all rgumentative or confrontational -

Definitely.

Quote:

Relativity is not my field, so I could not confidently agree or disagree with what anyone says about it. But, afaik relativity starts to give more-&-more improbable answers the closer we approach to things on subatomic scales. But afaik, it's not just scales as tiny as that, it's also inaccurate or "faulty" as we approach what we think is the very highly condensed state of the Big Bang ... but although that is often described as all matter and space shrunk down the smallest sub-atomic scale, afaik it would not have to be anywhere near that small ... it could be much larger than that, say the size of a golf ball, or a football, or even the size of the Earth, when extreme ("extreme" compared to our experiences on Earth now 1.8 billion years after the BB) quantum forces and extreme changes to gravity begin to dominate.

Yes and no. Yes, you're right that relativity seems to break down at certain scales (high energy/short distances). The singularity at the Big Bang is an example. That's why I expect its not the fundamental theory: something else is actually going on.
That's the yes. Why I say "no" is that we haven't actually observed or measured any of those scales where relativity breaks down. We can't see the Big Bang, we can only see the CMB. This situation is a little different from Newtonian physics: GR doesn't make any predictions that we can test which don't agree with either experiment or observation. Instead when we look at the implications of the theory they seem paradoxical, either because you get a singularity, or because when trying to make it consistent with QM you get infinities at the smallest scales. So it's probably wrong, but on the other hand we may simply be applying the theory wrong on those scales: we won't really know until we have a theory of quantum gravity.

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You might say that those are very extreme conditions and not what Relativity was ever intended to explain accurately ... but that looks exactly like the same as the criticism being levelled here at Newtons theory.

Yes, I agree that that would be the same.
As I said GR will probably turn out to be wrong in the same way that Newton was, but it's not certain yet.

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Well, as I say - I don't think any Theory can be actually "right about everything". That again is what we have learned from QM.

QM hasn't taught us that. Maybe you misunderstand what I meant by "right about everything": I probably should have said "right about everything that it says".

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To repeat the above - it fails when we get to the super-condensed phase of the Big Bang, doesn't it?

Probably, but we can't actually look at that phase and see.
As an example of how it may not fail, Hawking thought he could get rid of the singularity by using imaginary time. Similarly people used to think that the event horizon of a black hole was a singularity. It turns out it's just a coordinate singularity, there's no failure of the theory there, no physical problem, but originally it was thought that there was. It's at least possible that the big bang will turn out to be something similar (I doubt it though).

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Originally Posted by roboramma

QM doesn't suggest that we can't have laws that are models of the underlying reality. The equations of quantum mechanics are the most precisely tested theory we've ever had and they are in agreement with every experiment ever done.

I don't think I said anything different from that, did I?

Then I don't understand your point related to QM. QM gives a model of the universe that's consistent with the most precise experiments and observations we can make. While it could only be an approximation to a deeper underlying reality, it could also turn out to simply be correct: the universe may simply be quantum fields interacting exactly as described by the schrodinger equation.

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I don't think that was originally the "goal" in Newtons time. I think in his day everyone believed that Theories like those of Newton did predict exactly how things would behave, under all conditions throughout the universe.

But I think what we have since learned from QM, is that, that is the most we can ever hope for. I.e., if QM is correct then the best we can do is to get results that show a probability of how things will behave.

I think I may see some of our difference here: I am a fan of the Many Worlds Interpretation of QM. The schrodinger equation is a deterministic description of the universe, and the probabilities are simply a reflection of the fact that we don't know which branch of the wavefunction we're on.

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But more than that, afaik QM itself will almost certainly need to be improved/modified, both to obtain a more accurate picture of subatomic interactions generally, i.e. hence QFT replacing QM, but also to get an accurate description of what happened during and "before" the Inflationary stage of the Big Bang (that's assuming of course that (a) there was an inflationary stage more-or-less as Alan Guth and others have described it, and (b) assuming that there was in fact a BB close to what has been described).

Yes, but what's added by future developments may not contradict any current understanding. We probably* won't have to modify the schrodinger equation.

*Probably? It's hard to say how likely it is, but at least possibly.

[theprestige]

Originally Posted by LarryS

Odd that a philosophy forum would so consistently descend into philosophy

What's interesting is that it's always a descent. The forum never rises to philosophy.

[LarryS]

Originally Posted by Rystiya

'What do you think is inherently somehow beyond the possibility of being investigated or understood through a scientific approach? ' Science can't tell whether everything you know is just an illusion. Which is quite obvious. Since science is all based on analysing our experiences (that include all we feel and observe), if our experiences are just illusion, science is screwed.

"I and others are still waiting to hear a plausible explanation of how we have experiences of such things without the real-world objects existing". As I have said, perhaps you are a dark god dreaming about this world. Obviously you don't have a physical brain in this case. Your mind, body, society, continent, everything is just your imagination. That's not very likely, but nevertheless possible.

Given a scenario such as 4 friends, each with a favorite libation in hand, watching and sharing comments regard a sunset - - it seems reasonable to assume that (1) the sunset is real and not an illusion, and not a simulation. And (2) the sunset is not created by any one or more of their finite minds.
Granting the above two claims is not really giving very much, and as an extra bonus, you get to have a conversation. Granting there is a real world still allows you to ask questions like you did above: "Your experiences indicates that the contents of your experiences are related to activities in your brain. That's true. But does that imply that the former is generated by the latter? How can physical materials generate none-physical experiences?"

[IanS]

Originally Posted by Roboramma

Definitely.



Yes and no. Yes, you're right that relativity seems to break down at certain scales (high energy/short distances). The singularity at the Big Bang is an example. That's why I expect its not the fundamental theory: something else is actually going on.
That's the yes. Why I say "no" is that we haven't actually observed or measured any of those scales where relativity breaks down. We can't see the Big Bang, we can only see the CMB. This situation is a little different from Newtonian physics: GR doesn't make any predictions that we can test which don't agree with either experiment or observation. Instead when we look at the implications of the theory they seem paradoxical, either because you get a singularity, or because when trying to make it consistent with QM you get infinities at the smallest scales. So it's probably wrong, but on the other hand we may simply be applying the theory wrong on those scales: we won't really know until we have a theory of quantum gravity.

Yes, I agree that that would be the same.
As I said GR will probably turn out to be wrong in the same way that Newton was, but it's not certain yet.



QM hasn't taught us that. Maybe you misunderstand what I meant by "right about everything": I probably should have said "right about everything that it says".


Probably, but we can't actually look at that phase and see.
As an example of how it may not fail, Hawking thought he could get rid of the singularity by using imaginary time. Similarly people used to think that the event horizon of a black hole was a singularity. It turns out it's just a coordinate singularity, there's no failure of the theory there, no physical problem, but originally it was thought that there was. It's at least possible that the big bang will turn out to be something similar (I doubt it though).



Then I don't understand your point related to QM. QM gives a model of the universe that's consistent with the most precise experiments and observations we can make. While it could only be an approximation to a deeper underlying reality, it could also turn out to simply be correct: the universe may simply be quantum fields interacting exactly as described by the schrodinger equation.




I think I may see some of our difference here: I am a fan of the Many Worlds Interpretation of QM. The schrodinger equation is a deterministic description of the universe, and the probabilities are simply a reflection of the fact that we don't know which branch of the wavefunction we're on.



Yes, but what's added by future developments may not contradict any current understanding. We probably* won't have to modify the schrodinger equation.

*Probably? It's hard to say how likely it is, but at least possibly.

I don't think there's really any significant difference between us on most of the above, except perhaps that highlighted paragraph, where I am mystified as to why you think I'd ever said that QM did NOT give us the most accurate representation of the world around us, as experimentally tested to accuracy levels as high as approaching 1 part in 10*10 … I've said that here many times in this thread ... so I'm left a little surprised if you think I've ever played down the accuracy or importance of QM as our best theory of describing the fundamental building blocks of everything in our observed universe.

However, it's been modified quite a lot by quantum field theory, and that's the interpretation that we all really use now, so that's a difference (which we think is an advance) ... and there remain some results which look inexplicable and very surprising, eg as mentioned earlier, the results from more recent more sophisticated versions of the double slit experiment which seem to confirm effects such as superposition and entanglement which many would regard as hard to believe and rather difficult to fully explain ... though whether that's pointing to a fundamental error or flaw in the theory I of course do not know (I don't suppose anyone knows at the moment).

There has also been a history within the development of QFT over more that 50 years now, of various attempts to derive more convincing methods of so-called “renormalisation” that have to be introduced to handle various infinity issues that result in the maths (its' also applied to various mass-charge interactions), so I think there have at times been some doubts there about exactly how valid some of the maths has been in certain parts of QM and QFT approaches. That's not to say the the whole thing can/should be doubted, but just to say that various advances have been made where later authors have pointed out problems with some of the earlier mathematical treatment of field interactions. But as I freely said earlier, I'd be getting seriously out of my depth here if I started to imply that I am intimately familiar with all the maths of QFT.

And there is still the issue of how to include gravity within QFT. Afaik the progress there is mainly with models from String Theory and with Loop Quantum Gravity. But so far those are not actually included directly within the QFT model.

None of that is to suggest any great doubts about QM/QFT as an extremely accurate and very successful model of how all the underlying particle-forces (field excitations) explain the world around us. But it's just to point out that afaik, even with something as successful as QM/QFT there is still research to be done (which is being done) to solve various problems.

[IanS]

Originally Posted by LarryS

Given a scenario such as 4 friends, each with a favorite libation in hand, watching and sharing comments regard a sunset - - it seems reasonable to assume that (1) the sunset is real and not an illusion, and not a simulation. And (2) the sunset is not created by any one or more of their finite minds.
Granting the above two claims is not really giving very much, and as an extra bonus, you get to have a conversation. Granting there is a real world still allows you to ask questions like you did above: "Your experiences indicates that the contents of your experiences are related to activities in your brain. That's true. But does that imply that the former is generated by the latter? How can physical materials generate none-physical experiences?"

Well that final highlight is just what's known as an "argument for incredulity/ignorance". I.e., you are saying that because you personally cannot think of how our brain & sensory system could possibly give us the sensation of thinking/awareness, that it must be some inexplicable fundamental mystery that is impossible for science ever to explain.

Though a few pages back I did describe what I think is a highly plausible explanation of how 3 billion years of evolution has taken living things from an early state of merely having a cellular structure which produces various chemical responses to input from light and heat etc. in the environment around them (eg photosynthesis), all the way through trillions of advances in trillions of different species of life, to modern humans where the brain is now so highly evolved and so complex, and parts of the sensory system so highly refined and suited to the sort life we lead and the tasks we have to perform as great apes (as distinct from what's required for, say, ants or birds or fish etc.), that we now get a sort-of continuous running film-like monitoring of sensory detection, reaction, and changes being rapidly sent back & forth to the brain, where all taken to together it seems to us a sensation of real-time awareness monitoring sight, sound, touch, smell etc., ... ie compared with more primitive systems in other life-forms, where the sensory recognition would be more like a set of still images which only get changed relatively slowly ... that's an analogy of course (ie comparing it to moving film), but I can see from an explanation like that, how we could very easily have evolved to the stage that we have now, where we have such a sophisticated system of those responses that it seems to us like continuous awareness, ie consciousness.

[Darat]

Originally Posted by LarryS

…snip… How can physical materials generate none-physical experiences?"

No one claims that, experiences are the physical reactions, you want to add something on top of that but there is no requirement for such an addition and more importantly no evidence that supports such a claim.

[Roboramma]

Originally Posted by IanS

I don't think there's really any significant difference between us on most of the above, except perhaps that highlighted paragraph, where I am mystified as to why you think I'd ever said that QM did NOT give us the most accurate representation of the world around us, as experimentally tested to accuracy levels as high as approaching 1 part in 10*10 … I've said that here many times in this thread ... so I'm left a little surprised if you think I've ever played down the accuracy or importance of QM as our best theory of describing the fundamental building blocks of everything in our observed universe.

However, it's been modified quite a lot by quantum field theory, and that's the interpretation that we all really use now, so that's a difference (which we think is an advance) ... and there remain some results which look inexplicable and very surprising, eg as mentioned earlier, the results from more recent more sophisticated versions of the double slit experiment which seem to confirm effects such as superposition and entanglement which many would regard as hard to believe and rather difficult to fully explain ... though whether that's pointing to a fundamental error or flaw in the theory I of course do not know (I don't suppose anyone knows at the moment).

There has also been a history within the development of QFT over more that 50 years now, of various attempts to derive more convincing methods of so-called “renormalisation” that have to be introduced to handle various infinity issues that result in the maths (its' also applied to various mass-charge interactions), so I think there have at times been some doubts there about exactly how valid some of the maths has been in certain parts of QM and QFT approaches. That's not to say the the whole thing can/should be doubted, but just to say that various advances have been made where later authors have pointed out problems with some of the earlier mathematical treatment of field interactions. But as I freely said earlier, I'd be getting seriously out of my depth here if I started to imply that I am intimately familiar with all the maths of QFT.

And there is still the issue of how to include gravity within QFT. Afaik the progress there is mainly with models from String Theory and with Loop Quantum Gravity. But so far those are not actually included directly within the QFT model.

None of that is to suggest any great doubts about QM/QFT as an extremely accurate and very successful model of how all the underlying particle-forces (field excitations) explain the world around us. But it's just to point out that afaik, even with something as successful as QM/QFT there is still research to be done (which is being done) to solve various problems.

I agree with everything you say here.

What I took issue with was:

Quote:

Now, we know that 100% certainty like that is probably impossible in a quantum universe.

It's true that the uncertainty principle is a real thing, but that doesn't say anything about the correspondence of the model to reality.

Our current models are probably flawed in some way. But reality is doing something, and as such I expect that some model that corresponds to it perfectly is possible, though I'm not entirely confident that we'll ever get such a model.

In spite of that uncertainty, the framework of quantum physics may actually correspond to the underlying reality in all the things it actually says about it, without being a complete description (there are things left out, but it's at least possible that the things included are all correct, if you know what I mean).

[IanS]

Originally Posted by Roboramma

I agree with everything you say here.

What I took issue with was:


It's true that the uncertainty principle is a real thing, but that doesn't say anything about the correspondence of the model to reality.

Our current models are probably flawed in some way. But reality is doing something, and as such I expect that some model that corresponds to it perfectly is possible, though I'm not entirely confident that we'll ever get such a model.

In spite of that uncertainty, the framework of quantum physics may actually correspond to the underlying reality in all the things it actually says about it, without being a complete description (there are things left out, but it's at least possible that the things included are all correct, if you know what I mean).

Oh, ...OK, I think there's a clear misunderstanding here, or rather we are at "cross purposes". I did not mean to imply that QM/QFT is not reflecting reality. Everything I've said in this thread has been to say that I see no reason to believe that the world is anything other than the way we all detect it to be (I'm ignoring differences such as limitations of human eyesight or hearing etc. ... and ignoring the likely fact that when we detect what appear to be completely solid objects, the objects are actually composed of atoms and molecules with what's usually said to be vast amounts of "empty space" between all the various particles ... except of course, now with our QFT picture of atoms, that space is known to be far from "empty") ...

... so of course I think what we detect as reality, does of course exist. And actually I'd go much further (I've said this several times before in this thread) to say that I think it's almost certainly very close indeed to exactly what we detect it to be via our normal senses.

What I meant about the probabilistic nature of QM, is only to say that it means we cannot claim to find ultimate 100% precision so as to be literally certain (or having a "proof") of exactly how any subatomic particle will behave at any particular instant ... and that actually extends even to macroscopic objects; That is - even for macroscopic objects, there is (according to QM) some probability, however small, that the object will instantaneously behave in some completely unexpected and seemingly impossible way (such as disappearing in front of your eyes, and reappearing on the surface of the Moon ... or more likely, just the constituent parts, ie the subatomic "particles" suddenly relocating to various other positions in space (space-time) … though of course we'd probably have to wait for a time much greater than the lifetime of our universe.

Really, though it's discussions like this, that have for some time now been persuading me that I really do need to get back into the full maths of QFT, even though that is going to be a major task that will probably take more years than I have left on this Earth.

[LarryS]

Originally Posted by Darat

No one claims that, experiences are the physical reactions, you want to add something on top of that but there is no requirement for such an addition and more importantly no evidence that supports such a claim.

I was copying the question from Rystiya, not asking it myself. Having said that, asren't experiences (consciousness) considered an emergent property of physical matter? Being an emergent property it's an abstrqction, not physical.

[sackett]

As to the question asked in the thread title:

Just close your eyes, click your heels three times, and say, "There's no era like post modern no more!"


There. See how different everything is now?

[Darat]

Originally Posted by LarryS

I was copying the question from Rystiya, not asking it myself. Having said that, asren't experiences (consciousness) considered an emergent property of physical matter? Being an emergent property it's an abstrqction, not physical.

Nope it’s as physical as running is.

[LarryS]

Originally Posted by Darat

Nope it’s as physical as running is.

running is an idea we coorelate/attach with a set of physical actions, similarly like digestion, photosynthesis, etc.

[Darat]

Originally Posted by LarryS

running is an idea we coorelate/attach with a set of physical actions, similarly like digestion, photosynthesis, etc.

Spot on - exactly what experiences are.