Debate Macroscopic Realism: Define or Disbelieve?

[ThomasT]

As I said in post #4 of this thread, it is possible to have nonseparable, but local, reality via ontological structural realism ...

Ok, so I suppose we agree that nonseparability (whether of the ontological sort of metaphysical speculations, or the statistical sort of successful entanglement experiments) doesn't necessarily preclude an exclusively local reality, regardless of scale.

I agree with you that the path to an understanding of the fundamental nature of reality isn't through supercolliders.

I agree with your answer to ConradDJ's question, and your statement that a physical object is just an interactional context ("its 'web of physical interactions'"). The objectively real world that we share, the macroscopic reality, is the web of interactions defined by the capabilities of our sensory faculties and instruments that we use to augment those capabilities.

ConradDJ said:

We haven't really tried to describe the web in its own right ...

If, "in its own right" means at the most fundamental level, then I agree.

Thanks for the reference to your paper. It's fascinating and abstract. I think I roughly understand what you're trying to accomplish with it, even if I haven't taken the time (yet?) to understand it in detail. With that limitation (wrt my not fully understanding your program) in mind, I have to say that I don't think it's the right conceptual approach if the goal is to describe reality realistically (ie., dynamically).

As per your Weinberg reference, we agree that more fundamental doesn't necessarily mean smaller. It means more general. So, the deepest understanding that we might have of nature, and a physical mechanical answer to how a macroscopic reality emerges, would be to identify fundamental wave dynamical principle(s) that are evidenced in any and all behavioral scales.

I see physicists of the future doing computer simulations that maybe aren't possible now, effectively creating universes more or less like ours. Or, maybe this is possible now. I don't know.

Anyway, now I think I understand why one might not want to call macroscopic objects real -- if, for example, one thinks of fundamental reality in terms of dynamical principles rather than in terms of physical entities of a certain scale with certain behavioral characteristics.

We can of course differentiate between ontological and epistemological reality, but for us the question of ultimate or fundamental ontological reality is out of bounds, whereas the question of fundamental epistemological reality might be not only comprehensible but part of our ordinary everyday experience.

 

[Evolver]

In this thread I would like to start a debate on realism at the macroscopic level.
To some of you this may be an issue that looks so trivial that it doesn't make any sense to try to talk about it. It is my hope that you still may be interested in making some comment, especially if someone else disputes what you have already classified as trivial.
The kind of situation that I am referring to as macroscopic realism is in connection with large objects, such as those that we can see around us.
It could be argued that this thread does not belong in QM but in classical mechanics. But in classical mechanics realism is a given. It is only by studying how the macroscopic world results from the interaction of microscopic systems that this issue sometimes arises.
I see mainly two possibilities here with some people having positions in between.
If you believe in realism at the macroscopic level, how do you define it?
If you don't believe in it, could you still define it? not as a fact of nature but as a belief other people may have?. In this case, what is your picture of the world (only at the macroscopic level)?

I would have to invoke relativity on this one. Just as motion, acceleration, speed, etc are all relative... so too is a perception of reality.

You could define reality by what is being perceived and more importantly comprehended. Though a person in a coma is still a person, they undeniably do not experience the same reality as a normally functioning person.

Take wavelengths of light for example. We see different colors based on the limited range of wavelengths that we can perceive with our organ (the eye) that has adapted to seeing such wavelengths. Now, this being said, the wavelengths extend to possibly infinite lengths in either direction of our limited range. In effect meaning, colors exist that we will never see... innumerable amounts more than we can actually see in fact. But if I ask you to imagine just one, you will be hopelessly stumped as we cannot perceive things that we have not experienced. In essence, things we cannot perceive in any way, do not exist to us, whether they are part of a greater or more truthful reality or not. Colors we cannot "see" do not exist to us, because they affect us in no way, even if they are in fact real.

Other animals, such as a pit viper or a dolphin, have organs adapted for "seeing" other versions of reality such as heat or sonar respectively. These are ways of perception and comprehension that we do not posses as humans. We can use machines to mimic these perceptions, but this is moot because, for instance, we can never truly "see" what ultraviolet or infrared light looks like. Our eyes will always give us a representation based on the colors that it is privy to.

This implies that reality is one thing... and conscious entities perceive different portions of it... much like looking at the world outside through a keyhole, and every keyhole is a different shape and size. We are only subject to portions of reality. Or better yet, the Elephant and blind men allegory: Three blind men attempt to feel what an elephant is, one grabs the tusks proclaiming an elephant is smooth and hard, the second grabs the tail stating an elephant is bristly, the third grabs the trunk saying an elephant is long and slender. All three men are correct in their descriptions of the reality of portions of the elephant... but all of them are wrong in describing the elephant as a whole.

The trickery in this question is that only a conscious being may pose the query "What is reality?" And innately a conscious being will only experience parts of it.

Interacting particles of matter and forces more truthfully represent a pure reality, but we are unable to perceive them in a true sense, and thus... it is all relative.

 

[alexepascual]

Or better yet, the Elephant and blind men allegory: Three blind men attempt to feel what an elephant is, one grabs the tusks proclaiming an elephant is smooth and hard, the second grabs the tail stating an elephant is bristly, the third grabs the trunk saying an elephant is long and slender. All three men are correct in their descriptions of the reality of portions of the elephant... but all of them are wrong in describing the elephant as a whole.
The trickery in this question is that only a conscious being may pose the query "What is reality?" And innately a conscious being will only experience parts of it.
Interacting particles of matter and forces more truthfully represent a pure reality, but we are unable to perceive them in a true sense, and thus... it is all relative.

But those people touching different parts of the elephant can exchange information and eventually make a model of the elephant. That's what we do in science. Some times we get the complete picture and some times we don't. In the macroscopic world, even when we don't have the complete picture we assume that there is an underlying reality and that if we get more data we should be able to at least get a more precise description. I am not saying that this picture is the one that will prevail after we consider the possible effects of QM at the macroscopic level, but at least that's the piture that we get based on classical physics and day-to-day experience.

 

[Wangf]

Maybe some one will find an elegant probability formula for all microscopic and macroscopic reality.

My feeling is: 100% non-locality superposition status for Planck level..
99.99999999...% non-locality superposition status for atom level..
99.99...% non-locality superposition status for C 60 molecule level..
.
.
.
0.00000000000000...1% non-locality superposition status for human being size level...

So in this way, we do NOT need to draw a fine line between microscopic and macroscopic levels.

Macroscopic is simply a diminishing probability due to "degree of complexity."

Probability (superposition) = Formula ( complexity vs. Planck level)
copyright of Felix Wang

 

[Evolver]

But those people touching different parts of the elephant can exchange information and eventually make a model of the elephant. That's what we do in science. Some times we get the complete picture and some times we don't. In the macroscopic world, even when we don't have the complete picture we assume that there is an underlying reality and that if we get more data we should be able to at least get a more precise description. I am not saying that this picture is the one that will prevail after we consider the possible effects of QM at the macroscopic level, but at least that's the piture that we get based on classical physics and day-to-day experience.

What you are saying is still in accordance with my argument... true, the blind men could exchange information and thus create a model of the elephant, but they will still never see the elephant. The same as we understand that ultraviolet and infrared wavelengths exist, but we will still never see them, even with machinery, because our eyes will still only give a representation based on the colors they can comprehend.

This being said, for the sake of this argument I think we must differentiate between reality and existence. Existence would be all the things that do exist objectively, and reality is what portion of existence and organism is sensitive to on a subjective level.

We too can create a model via formulas and experimentation of what existence is, and I agree that is what science does. But that doesn't mean it is our reality. Much as the blind men could conceive the elephant based on touch, we can interpret existence only relative to our reality.

 

[alexepascual]

What you are saying is still in accordance with my argument... true, the blind men could exchange information and thus create a model of the elephant, but they will still never see the elephant. The same as we understand that ultraviolet and infrared wavelengths exist, but we will still never see them, even with machinery, because our eyes will still only give a representation based on the colors they can comprehend.

This being said, for the sake of this argument I think we must differentiate between reality and existence. Existence would be all the things that do exist objectively, and reality is what portion of existence and organism is sensitive to on a subjective level.

We too can create a model via formulas and experimentation of what existence is, and I agree that is what science does. But that doesn't mean it is our reality. Much as the blind men could conceive the elephant based on touch, we can interpret existence only relative to our reality.

Words are just a an ordered set of letters and they don't have a meaning per se. We assign a meaning to them, and the same word sometimes means a different thing in different countries, or different parts of a country (even if the same language is spoken).
As we use language to communicate with each other, if we use the same word with a different meaning that can be a source of confusion. But it does not necessarily mean that one person is right and the other is wrong. Now, if we want to avoid confusion, it always helps to use words by giving them the same meaning. I think the easiest way to do this is to figure out which is the most common meaning (at least that used within the subject being discussed). In the case of "reality", I don't think most people would consider this different from "existence", even though some times "existence" can be used for abstract things in mathematics. When I said "reality" I meant that "objective reality" which is usually visualized in classical physics as a 4-D universe. So the use I gave it would be very similar to "existence". If you ask philosofers, they will give you all sorts of definitions, and will make a lot of subtle distinctions between words. But I don't think they usually have as a goal to make things more clear. All the opposite, they try to make things murky so that people believe they know what they are talking about. It is not that I am against philosofy, I just dislike the way most philosofers approach the subject.

 

[Evolver]

Words are just a an ordered set of letters and they don't have a meaning per se. We assign a meaning to them, and the same word sometimes means a different thing in different countries, or different parts of a country (even if the same language is spoken).
As we use language to communicate with each other, if we use the same word with a different meaning that can be a source of confusion. But it does not necessarily mean that one person is right and the other is wrong. Now, if we want to avoid confusion, it always helps to use words by giving them the same meaning. I think the easiest way to do this is to figure out which is the most common meaning (at least that used within the subject being discussed). In the case of "reality", I don't think most people would consider this different from "existence", even though some times "existence" can be used for abstract things in mathematics. When I said "reality" I meant that "objective reality" which is usually visualized in classical physics as a 4-D universe. So the use I gave it would be very similar to "existence". If you ask philosofers, they will give you all sorts of definitions, and will make a lot of subtle distinctions between words. But I don't think they usually have as a goal to make things more clear. All the opposite, they try to make things murky so that people believe they know what they are talking about. It is not that I am against philosofy, I just dislike the way most philosofers approach the subject.

I think you are misunderstanding what I am saying. First off if you re-read what I wrote, I said for the sake of the argument we must differentiate between reality and existence, and then I clearly defined them.

If you are implying that the underlying rules of the universe are all perceived coherently by every organism, you are mistaken. You and I cannot perceive the individual fluctuations of quantum particles, though without those we would not exist. Therefore, they are not a part of our reality but are a part of our existence. What's more is that this is a discussion on macroscopic realism... so the entire point of this thread is to attempt to make that distinction. Your lack of interest in trying to discuss the two things (regardless of opinion) means you may be on the wrong thread.

As for your unwarranted disdain for philosophers; science would be in a world of hurt without them. Most of the major remodeling of our understanding of science is done by theoretical physicists... emphasis on theoretical. These are philosophers, with a heavy background in mathematics and physics, that attempt to find new ways of explaining the universe. An experimentalist will then put these theories to the test. Einstein is one such "philosopher" that you have bashed with vague generalities.

You are quick to blast things like philosophers (not philosofers by the way) but in all your haste to proclaim that we must accurately define things, you have immediately failed to give meaning to the word philosopher... by your definition they are just people that make science unclear and murky. Here is a definition of philosophy taken from the dictionary: "the rational investigation of the truths and principles of being, knowledge, or conduct."

This is where things in science come to a real halt. When you do not clearly define your concepts... and even more when you openly contradict yourself in your own argument.

 

[WaveJumper]

If you ask philosofers, they will give you all sorts of definitions, and will make a lot of subtle distinctions between words. But I don't think they usually have as a goal to make things more clear. All the opposite, they try to make things murky so that people believe they know what they are talking about. It is not that I am against philosofy, I just dislike the way most philosofers approach the subject.

That'd be because most philosophers are aware that they can not get a solid footing on knowing reality and existence. To know what 'knowing' is, is circular reasoning and appears impossible. As far as i can tell, the "science will answer the Big questions" attitude is long gone from theoretical physics.

 

[alexepascual]

I think you are misunderstanding what I am saying. First off if you re-read what I wrote, I said for the sake of the argument we must differentiate between reality and existence, and then I clearly defined them.

If you are implying that the underlying rules of the universe are all perceived coherently by every organism, you are mistaken. You and I cannot perceive the individual fluctuations of quantum particles, though without those we would not exist. Therefore, they are not a part of our reality but are a part of our existence. What's more is that this is a discussion on macroscopic realism... so the entire point of this thread is to attempt to make that distinction. Your lack of interest in trying to discuss the two things (regardless of opinion) means you may be on the wrong thread.

As for your unwarranted disdain for philosophers; science would be in a world of hurt without them. Most of the major remodeling of our understanding of science is done by theoretical physicists... emphasis on theoretical. These are philosophers, with a heavy background in mathematics and physics, that attempt to find new ways of explaining the universe. An experimentalist will then put these theories to the test. Einstein is one such "philosopher" that you have bashed with vague generalities.

You are quick to blast things like philosophers (not philosofers by the way) but in all your haste to proclaim that we must accurately define things, you have immediately failed to give meaning to the word philosopher... by your definition they are just people that make science unclear and murky. Here is a definition of philosophy taken from the dictionary: "the rational investigation of the truths and principles of being, knowledge, or conduct."

This is where things in science come to a real halt. When you do not clearly define your concepts... and even more when you openly contradict yourself in your own argument.

I apologize if I offended you. And I also apologize for misspelling "philosopher". I am not a native English speaker. Perhaps I misunderstood what you were saying but I also think you misunderstood what I was saying. And I think that you are taking things personally, and when a conversation takes this turn is very hard to go back to regular exchange of ideas.
As I said before, I don't have anything against philosophy. And I do understand that there is a lot of philosophical thought behind the ideas of some of the great physicists. I just said that I disliked the way most philosophers approach the subject. We all have things we like and things we dislike. I just expressed something I dislike. I don't think this should be a motive to get into a heated argument full of anger.
With respect to Einstein, I think he was a good example of someone humble who tried to make the complex simple, instead of doing it the other way around. His thinking was philosophical but he communicated his ideas in simple terms that everybody could understand. When explaining special relativity, he was using clocks and sticks for instance. So, to understand Einstein you don't need to take a separate course in philosophy.
In the physics community, there is some times an aversion to anything that can be labeled as "metaphysical" and I think this aversion comes mainly from the orthodox interpretation proponents. I must say that I don't like that position either, so I hope you don't mistake me as someone who is assuming that position.
With respect to the word "reality", all that I was saying is that I don't think the definition that you are giving to that word is that which most people would use. Your position, on the other hand is that you know the true meaning of the word and that I don't. So we end up arguing about the meaning of words instead of arguing about the concepts. You may say: well, if we are using a word with different meanings then we do need to argue about the meaning before we can move on. I would agree. But one thing is to have a conversation where you exchange some ideas about the usage of that word and a different thing is when you endup in an unending argument about who is right and who is wrong. I would rather seek some consensus about the terminology and move on. But in this case it may be too late for that.

 

[Evolver]

I apologize if I offended you. And I also apologize for misspelling "philosopher". I am not a native English speaker. Perhaps I misunderstood what you were saying but I also think you misunderstood what I was saying. And I think that you are taking things personally, and when a conversation takes this turn is very hard to go back to regular exchange of ideas.
As I said before, I don't have anything against philosophy. And I do understand that there is a lot of philosophical thought behind the ideas of some of the great physicists. I just said that I disliked the way most philosophers approach the subject. We all have things we like and things we dislike. I just expressed something I dislike. I don't think this should be a motive to get into a heated argument full of anger.
With respect to Einstein, I think he was a good example of someone humble who tried to make the complex simple, instead of doing it the other way around. His thinking was philosophical but he communicated his ideas in simple terms that everybody could understand. When explaining special relativity, he was using clocks and sticks for instance. So, to understand Einstein you don't need to take a separate course in philosophy.
In the physics community, there is some times an aversion to anything that can be labeled as "metaphysical" and I think this aversion comes mainly from the orthodox interpretation proponents. I must say that I don't like that position either, so I hope you don't mistake me as someone who is assuming that position.
With respect to the word "reality", all that I was saying is that I don't think the definition that you are giving to that word is that which most people would use. Your position, on the other hand is that you know the true meaning of the word and that I don't. So we end up arguing about the meaning of words instead of arguing about the concepts. You may say: well, if we are using a word with different meanings then we do need to argue about the meaning before we can move on. I would agree. But one thing is to have a conversation where you exchange some ideas about the usage of that word and a different thing is when you endup in an unending argument about who is right and who is wrong. I would rather seek some consensus about the terminology and move on. But in this case it may be too late for that.

Believe me, I have not become personally offended in the least. I was only vehemently defending philosophy, which I believe is a crucial ingredient when it comes to theoretical thinking. Equally important are an understanding of physics as well as a backbone of mathematics. If you would have expressed a dislike for either of those I would have just as readily defended their importance. Though this is getting slightly off topic, believe me when I say there are no personal issues here, I am only interested in the exchange of ideas, and I would like nothing more than for that to continue.

As for philosophers, they receive flak for attempting to force definitions of concepts. They ardently push for defining things, because definition equals clarity. If anything, they should be thanked for that contribution as the inverse to attempting to force definition, is that assumptions get made. And when scientific "fact" becomes based on assumption... then there is a serious problem. I'm not sure what philosophers you are speaking of that attempt to convolute people's thoughts, but that sounds more like a personal problem with that individual "philosopher" as opposed to a problem with philosophy in general.

Because philosophers push for definition and clarity, they attempt to define things that very often are hard to define, so it becomes labeled as metaphysical. Before Einstein had enough pieces of the puzzle for his theories of relativity, they could have been thought of as metaphysical concepts. Here is a dictionary definition of metaphysical:

"a. concerned with abstract thought or subjects, as existence, causality, or truth.
b. concerned with first principles and ultimate grounds, as being, time, or substance."

According to these definitions... Einstein's theories are STILL considered metaphysical.

Any philosopher worth their weight in gold would NEVER attempt to make a concept more complex. If they did, then by definition, they wouldn't even be a real philosopher.

And you're right, I feel in order to continue in conversations there has to be a universal understanding of words involved. That's why physics uses equations with symbols that represent a concept.. there is no debate to that symbols meaning then. In our case, I was trying to establish those definitions by attempting to define "reality" and existence". And you're right, maybe most people wouldn't agree with my definition of reality... but reality is subjective, and when you are trying to compare it with something that is objective (like how i defined existence) then new definitions are required.

 

[alexepascual]

Believe me, I have not become personally offended in the least. I was only vehemently defending philosophy, which I believe is a crucial ingredient when it comes to theoretical thinking. Equally important are an understanding of physics as well as a backbone of mathematics. If you would have expressed a dislike for either of those I would have just as readily defended their importance. Though this is getting slightly off topic, believe me when I say there are no personal issues here, I am only interested in the exchange of ideas, and I would like nothing more than for that to continue.

As for philosophers, they receive flak for attempting to force definitions of concepts. They ardently push for defining things, because definition equals clarity. If anything, they should be thanked for that contribution as the inverse to attempting to force definition, is that assumptions get made. And when scientific "fact" becomes based on assumption... then there is a serious problem. I'm not sure what philosophers you are speaking of that attempt to convolute people's thoughts, but that sounds more like a personal problem with that individual "philosopher" as opposed to a problem with philosophy in general.

Because philosophers push for definition and clarity, they attempt to define things that very often are hard to define, so it becomes labeled as metaphysical. Before Einstein had enough pieces of the puzzle for his theories of relativity, they could have been thought of as metaphysical concepts. Here is a dictionary definition of metaphysical:

"a. concerned with abstract thought or subjects, as existence, causality, or truth.
b. concerned with first principles and ultimate grounds, as being, time, or substance."

According to these definitions... Einstein's theories are STILL considered metaphysical.

Any philosopher worth their weight in gold would NEVER attempt to make a concept more complex. If they did, then by definition, they wouldn't even be a real philosopher.

And you're right, I feel in order to continue in conversations there has to be a universal understanding of words involved. That's why physics uses equations with symbols that represent a concept.. there is no debate to that symbols meaning then. In our case, I was trying to establish those definitions by attempting to define "reality" and existence". And you're right, maybe most people wouldn't agree with my definition of reality... but reality is subjective, and when you are trying to compare it with something that is objective (like how i defined existence) then new definitions are required.

Wikipedia makes an attempt to be unbiased and to reflect common knowledge about particular subjects. The following is the beginning of the entry on reality there:

Reality, in everyday usage, means "the state of things as they actually exist." In a sense it is what is real.[1] The term reality, in its widest sense, includes everything that is, whether or not it is observable or comprehensible. Reality in this sense includes being and sometimes is considered to include nothingness, where existence is often restricted to being (compare with nature).
The term 'reality' First appeared in the English language in 1550, originally a legal term in the sense of "fixed property." It originated from the Modern Latin term 'realitatem' which was from Late Latin 'realis'; The meaning such as "real existence" is from 1647 onwards." [2]

If you go and see what different philosophical schools of thought have to say about reality, you will find many different definitions. The definition above entails an external reality separate from our perception. Of course positivists and to an extreme solipsists would question that. But when it comes to day-to-day life, I think the definition above is what most people have in mind, and it conveys a meaning clear enough for people to communicate. The exact wording of the definition above could be disputed, but you can see that it does not make a big distinction between "reality" and "existence".
I think most people would consider as "reality", the set of objects and events that "are out there" or, in other words, "exist". Of course this implies that you believe that these things actually exist independent from your perception, but most people do have that belief. Now, let's assume for a moment that I deny the existence of things which I don't or can't perceive (let's ignore the difference for this argument). I could still use the word "reality" with the same meaning than those who do believe in a separate existence assign to it. The reason I can do that is because I can picture in my mind what they think. So, using the word with the same meaning I could say that I don't believe in "reality", and even we have opposite views, we can still communicate and understand what the differences are because we both agree on the meaning of the word "reality".
The same could be said of other words. I may say "I don't believe in God". When I say God, I am referring to the concept that most people have in mind when they say it. Someone may always want to split hairs and say that different religions have a different concept of God. But when I say God, I am referring to a generalization of all these ideas, (giving more preponderance to the most common).
Some may even say that my concept of God is wrong, that they have the right definition. But there is no right or wrong definition of God. God is just three letters and it can be used for any purpose you like. It is just that we try to use it in a consistent way so that we can communicate with each other and have some certainty that when someone says the word, the picture they have in their mind is what we think. If we use the most common definition, then there is better chance of not having misunderstandings.
Back to "reality", I think its usage in physics refers to the world out there (as opposite to our imagination, dreams, hallucinations, etc). Of course we should say that if we believe that mental processes are the result of brain activity, then imagination, dreams and hallucinations are also real as processes. But what we don't consider real is their content, what they represent. Someone could also dispute this. Everything can be argued, and you can have an unending discussion. But if we try to ignore some of the differences (as long as they don't pop up as a big stumbling block) and look for some common ground, that may be more beneficial.
When I initiated this thread, I had in mind initiating a debate about the validity of the concept of reality at the macroscopic level, specially considering that amplification (measurement) of a quantum event can produce paradoxical results. I did not have in mind getting into a discussion of what "reality" means, because I thought there was enough consensus on it's meaning.
In other posts I have tried to steer the discussion more in that direction. When we think about reality, we think of certain objects out there which have a more or less deffinite position, orientation, and other attributes. These attributes may change, but they have a more or less deffinite value at each moment in time. If, on the other hand, someone told us that a Schodringer cat can be "realy" in a superposition of live/dead then that would be a challenge to the concept of realism the way we normally understand it. This challenge could mean that simply we can't assume that all things can be classified as real or not real, or it could on the other hand mean that we need to modify our definition of reality to include "other realities" such as in the Many Worlds Interpretation of Quantum Mechanics.
At the microscopic level, this debate has been going on for a long time, having probably started with the famous discussions between Eintein and Bohr. But at the macroscopic level there is not much discussion. I think this is due to the fact that once a measurement is made, the state of the system is assumed to jump to one of the eigenvalues of the observable being measured, and classical reality is thought to emerge (Nowadays this process being described in terms of environment-induced decoherence).
Before you make a measurement of a quantum system you have a superposition of states, and the ordinary concept of reality is in conflict with that stage of the process. But once you made the measurement, you get a definite value for the observable. If you don't know what that value is, you can still describe the situation with a diagonal density matrix which represents a "mixture" of states as opposed to a "pure state". In the mixture, you assume that the system is "realy" in one of the eigenstates. So, after that point, there is (apparently) not problem with the concept of independent reality. Except for a few very peculiar cases, the transition from quantum to classical behavior happens when a microscopic (typicaly subatomic) quantum system interacts with a macroscopic one.

 

[kote]

I don't know if there's any debate when you ask about purely macroscopic existence. If you say, "nevermind the underlying nature, would you call this table real?" I don't know of anyone who would say no. If they do say no, it's because they disagree with you on the definition of reality or are thinking "not in the way you mean real." I would argue that all disagreements can be reduced to either incomplete knowledge or differing uses of terminology, but that's another issue.

When we ask if something is real on a microscopic level we can talk about whether or not certain theoretical entities are basic and complete or not. The whole point of physics and metaphysics, though, is to tell us what underlies the obvious existence of macroscopic objects, at least in our minds.

Philosophy studies how we can define reality so that it fits with a consistent world view and doesn't lead to contradictions. Naive definitions are rarely well defined or useful if you care about consistency and avoiding contradictions. It's too bad that things are almost never so simple!

 

[alexepascual]

I don't know if there's any debate when you ask about purely macroscopic existence. If you say, "nevermind the underlying nature, would you call this table real?" I don't know of anyone who would say no. If they do say no, it's because they disagree with you on the definition of reality or are thinking "not in the way you mean real." I would argue that all disagreements can be reduced to either incomplete knowledge or differing uses of terminology, but that's another issue.

When we ask if something is real on a microscopic level we can talk about whether or not certain theoretical entities are basic and complete or not. The whole point of physics and metaphysics, though, is to tell us what underlies the obvious existence of macroscopic objects, at least in our minds.

Philosophy studies how we can define reality so that it fits with a consistent world view and doesn't lead to contradictions. Naive definitions are rarely well defined or useful if you care about consistency and avoiding contradictions. It's too bad that things are almost never so simple!

It looks to me that what you are saying is that once any discrepancies about different use of terminology or some other details, people would agree about the adequacy of macroscopic reality. I agree with you. With respect to naive definitions, I think you can use them for a while and they are very useful until maybe at some point they run out of steam.
In the case of macroscopic reality, I would assume it to be a good model until some experiment displays a paradox that puts it in question.
With respect to what I mentioned earlier (Schrodinger's Cat). It appears that most physicists would consider the cat to be dead or alive (not both) gieven the fact that it is a macroscopic object and that it is entangled with the environment.
If the experiment was being done right now on Pluto (space-like). Would you say also that the cat needs to be considered alive or dead and not in a superposition?

 

[Evolver]

If you go and see what different philosophical schools of thought have to say about reality, you will find many different definitions. The definition above entails an external reality separate from our perception. Of course positivists and to an extreme solipsists would question that. But when it comes to day-to-day life, I think the definition above is what most people have in mind, and it conveys a meaning clear enough for people to communicate. The exact wording of the definition above could be disputed, but you can see that it does not make a big distinction between "reality" and "existence".

The problem with this argument is that this is a discussion on macroscopic reality in contrast to quantum or microscopic reality. When you generally define reality as to include both systems, then their immediately is no room for an open discussion on the differences of the two. By lumping macroscopic and microscopic interactions in the same category of the generally defined "reality" you have thus neutralized this thread entirely. When I attempted to differentiate between the two, it was for the sake of showing a difference in both their natures. And since Relativity and QM have yet to be unified, I think my justification of separate definitions is not only warranted, but necessary to make any headway in this discussion.

I think most people would consider as "reality", the set of objects and events that "are out there" or, in other words, "exist". Of course this implies that you believe that these things actually exist independent from your perception, but most people do have that belief. Now, let's assume for a moment that I deny the existence of things which I don't or can't perceive (let's ignore the difference for this argument). I could still use the word "reality" with the same meaning than those who do believe in a separate existence assign to it. The reason I can do that is because I can picture in my mind what they think. So, using the word with the same meaning I could say that I don't believe in "reality", and even we have opposite views, we can still communicate and understand what the differences are because we both agree on the meaning of the word "reality".

This is incorrect, you are assuming that you are able to picture in your mind a concept that you cannot comprehend. This is why ill-defined concepts that lead to assumptions will always stifle scientific thought. As an example I will go back to the wavelengths of light. We know the wavelengths extend beyond the ultraviolet and infrared spectra indefinitely. This indicates that if one had a receptor calibrated for those wavelengths, that a sense of those wavelengths would produce a result, much as the visible spectrum produces one in our eyes. This means their are colors that exist that we can never see, much less comprehend. No matter how hard you tried, you could NEVER imagine a color in your mind that existed in one of those spectra, no matter how much information of that idea was relayed to you.

The same could be said of other words. I may say "I don't believe in God". When I say God, I am referring to the concept that most people have in mind when they say it. Someone may always want to split hairs and say that different religions have a different concept of God. But when I say God, I am referring to a generalization of all these ideas, (giving more preponderance to the most common).

God is such a vague concept that it can never be used in a productive argument. If I asked 10 people on the street what they thought God was, I would get 10 different answers... even if they belonged to the same religion. The fact that you say you have "generalized" the meaning of God means there is no specific thing left to define. It has come to mean everything and nothing at the same time. God in an indefinable concept and as such can not be argued for or against by any scientific applications. This makes the concept of God irrelevant to our conversation.

When I initiated this thread, I had in mind initiating a debate about the validity of the concept of reality at the macroscopic level, specially considering that amplification (measurement) of a quantum event can produce paradoxical results. I did not have in mind getting into a discussion of what "reality" means, because I thought there was enough consensus on it's meaning.

I don't think you fully understood the implications of what you created then when you started this thread. The mere fact that you had to start a debate on macroscopic reality implies that there is another form of reality with which to contrast it. If there was one universal reality, as you have defined, there would be no debate here because it would include only one reality, macroscopic or otherwise. If you are willing to discuss distinct realities you must also then have different ways to describe them. If you are unwilling to attempt to differentiate between them, then there simply can be no discussion because we will have no grounds on which to discuss anything.

In other posts I have tried to steer the discussion more in that direction. When we think about reality, we think of certain objects out there which have a more or less deffinite position, orientation, and other attributes. These attributes may change, but they have a more or less deffinite value at each moment in time. If, on the other hand, someone told us that a Schodringer cat can be "realy" in a superposition of live/dead then that would be a challenge to the concept of realism the way we normally understand it. This challenge could mean that simply we can't assume that all things can be classified as real or not real, or it could on the other hand mean that we need to modify our definition of reality to include "other realities" such as in the Many Worlds Interpretation of Quantum Mechanics.

Or it could mean (and this is my personal opinion) that we are missing a large piece of the puzzle when it comes to understanding the universe around us. Most likely, any impossibilities and implausibilities stem not the from the universe itself, but from our primitive understanding of it. Much like when man thought the world was flat, or that the solar system was earth-centric... the universe did not change to prove us wrong, we simply changed our understandign of it to match what it was. Look at locality vs. non-locality issues. non-locality would imply relativity and QM must be violated or at least adapted to include these issues, but relativity and locality play a major part in our models of understanding the universe. So what that implies is that we are gravely mistaken about some concepts that we have yet to discover.

So, after that point, there is (apparently) not problem with the concept of independent reality. Except for a few very peculiar cases, the transition from quantum to classical behavior happens when a microscopic (typicaly subatomic) quantum system interacts with a macroscopic one.

Here lies another contradiction to what you have said. You have already established different realities. You stated that a transition is required, implying that the two are different and that they must be transitioned between. Yet in your argument above you allowed no room for alternate definitions of reality and have thus destroyed your own reasoning.

 

[daisey]

I feel like I'm trapped in a seemingly endless game of PacMan, running around trying to make it through each day without being caught. I'm sure that to some entity existing outside of our wonderful multi-dimensional realm, this is all just an extremely elaborate mathematical illusion. But to me, just like to the little PacMan in the video game, we still perceive our macroscopic world to be "real". That's because to us, it is. So, I guess it all depends on your perspective. Got to run...

Daisey