If a tree falls in the woods...

[srfriggen]

and no one is around to hear it does it make a sound?...

my real question is, does the tree even exist if no one is around? and what qualifies an "observer". do wave functions collapse only in the presence of humans? why can't schroedinger's cat tell if it is dead?

I guess I'm asking for a general overview so that I can contribute CORRECT information the next time conversation of this type starts. Nothing worse than asserting incorrect facts about physics, or anything for that matter.

[olgranpappy]

and no one is around to hear it does it make a sound?...
yes

my real question is, does the tree even exist if no one is around?
yes
and what qualifies an "observer". do wave functions collapse only in the presence of humans?
no
why can't schroedinger's cat tell if it is dead?

something dead does not know it is dead since it is dead.

I guess I'm asking for a general overview so that I can contribute CORRECT information the next time conversation of this type starts. Nothing worse than asserting incorrect facts about physics, or anything for that matter.

This thread should probably be moved to the philosophy section since the answers I gave are highly unsatisfactory.

[Marcaias]

do wave functions collapse only in the presence of humans?

Of course not!

However, the behaviour of the system is exactly the same as if all the "observations" made by the tree, the grass, the wildlife, and so on were instead made by you when you stumbled into the forest a year later.

[srfriggen]

jeez, way to take the question out of context and make it seem ridiculous. maybe someone else can give a less arrogant answer.

it's not a philosophical question, it's a question about wave function collapses and observation.

[srfriggen]

Of course not!

However, the behaviour of the system is exactly the same as if all the "observations" made by the tree, the grass, the wildlife, and so on were instead made by you when you stumbled into the forest a year later.


hey, my last comment wasn't aimed at you. i'm having a tough time wrapping my head around your answer. is there a way you can explain it further? I've heard people reply to the question, "if a tree falls in the woods does it make a sound" with "well, actually quantum theory tells us the tree doesn't even exist if we aren't around to observe it, therefore no sound can be made from a non-existent tree". comments on that?

[msumm21]

and no one is around to hear it does it make a sound?...

my real question is, does the tree even exist if no one is around?

if the fall leaks information out into the surrounding environment (limbs break, wildlife runs away, ...) then I guess it's real to your mind. couldn't you go measure things afterward and see that it broke?

[Marcaias]

hey, my last comment wasn't aimed at you. i'm having a tough time wrapping my head around your answer. is there a way you can explain it further? I've heard people reply to the question, "if a tree falls in the woods does it make a sound" with "well, actually quantum theory tells us the tree doesn't even exist if we aren't around to observe it, therefore no sound can be made from a non-existent tree". comments on that?

If any of the people who told you "the tree doesn't even exist if we aren't around to observe it" are physicists, please smack them for me. :)

To expand on what I meant...

In quantum computing, it's called the "principle of deferred measurement." I believe it to be the fundamental paradox in quantum mechanics, and the root of all the trouble people have in understanding it.

The evolution of a quantum system can be modeled by a series of continuous operations U, interspersed with discontinuous, "jumpy" measurements R of the whole or part of the system R. So you can conceptually think of the evolution of a quantum system as a continuous graph with a bunch of discontinuous jumps. (I take this picture directly out of the Road to Reality by Penrose.)

http://img228.imageshack.us/img228/8575/roadtorealitylx6.png

The principle of deferred measurement states that such an evolution can ALWAYS be replaced by one with a single, continuous U, and a single measurement R performed at the very end.

In computational terms, whenever you want to measure the value of a qubit and perform a routine like, "if I measure a 0, perform operation A; if I measure a 1, perform operation B," you can replace that measurement and procedure by a purely quantum operation.

In other words, you can always push back or defer an observation until the very end of your "computation."

In terms of a tree in the forest, you can reasonably say that the tree was in a "Schrodinger's Tree" state until you entered the forest and peeked at it. But you can just as reasonably say that when the tree fell, the ground measured its position, and so on, and so on, and by the time you finally peaked at it, you simply saw an already collapsed quantum system.

(The same principle made it so difficult for me to understand entanglement! The trouble with entanglement goes away if all the interactions are purely quantum ones until the two entangled particles "meet" and get measured, but it's incredible that any number of local measurements before the meeting, when the particles are miles apart, can be replaced by quantum operations. It seems as though a local measurement has an effect on the pair particle, but this effect is in a sense virtual.)

You might instead ask, what if I never observe the tree, and in fact no one ever goes inside it and no one observes whether the tree fell over or not?

It's in the answer to that question that you may be tempted to say, it simply doesn't exist, in the sense that it is a completely isolated system, and so anything that happens in it has no effect on us. However, completely isolated systems don't exist in reality. The universe is one, big quantum system where everything is connected on some level.

You can ask the same question outside of any quantum theory, if, say, you're trying to calculate the acceleration of a falling object on earth. The force of gravity exerted by the moon is so negligible that we can consider the earth an isolated system. But it's absurd to say the moon doesn't exist because of this.

[Dmitry67]

Sorry for repeating it again
There is no such thing as wavefunction collapse.
There is no R process.
http://en.wikipedia.org/wiki/Quantum_decoherence

Can we finally put Copenhagen interpretation to a place where it belongs - ether etc.

[Ivan Seeking]

From the wiki link

Environmental decoherence, that is the effects of an external agent on a quantum system, does not claim to offer answers to the main interpretational questions about quantum mechanics. Two points are essentially unanswered by this approach:

Environmental decoherence does not produce a collapse of the wavefunction, it simply provides an explanation for the appearance of wavefunction collapse.
Does an isolated quantum system ever collapse to a classical state? This could be an irrelevant question, since decoherence demonstrates that we can regard empirically the wavefunction as having collapsed; whether it actually has collapsed or not is not a meaningful question since collapse is not empirically determinable. Regarding the appearance of collapse: if the isolated system has sufficient complexity to support thermal, internal degrees of freedom then observers embedded with the isolated system would observe collapse.
The first point is easily understood in the following way. As said above, einselection removes interfering terms due to the external environment. The obtained state gives just independent probabilities for each selected state to be seen by a measurement apparatus. Collapse of a wavefuntion implies that just a possible state is singled out by measurement. The passage from independent probabilities for the states to a single one is not understood yet and this is a dark area that is still under hot discussion.

The second point appears just a scientific question to be answered by experiments and underlies a more subtle question as an effect could be at work for an isolated system becoming classical. A lot of work has been done about and several proposals have been put forward [17]. Some experimental results were also obtained. The problem implicated here is the irreversibility of time evolution and more technically, the understanding of Boltzmann's hypothesis of molecular chaos or Stosszahlansatz. This was the answer due to Boltzmann to the Loschmidt's paradox. Environmental decoherence does not give a satisfactory answer to this question, rather closed quantum systems are expected to keep on being quantum forever.

Finally, but not less important, is the cosmological problem. Universe is an isolated system and so how did it become classical? This extends to the more general problem of cosmological perturbations that appear to be strictly classical.

Currently it appears as the idea of environmental decoherence, surely correct, should be complemented with some other mechanism for isolated quantum systems. Anyhow, this is an open research problem and more results are to be expected in the future.

Why Decoherence has not Solved the Measurement Problem: A Response to P.W. Anderson
Stephen L. Adler
Institute for Advanced Study, Princeton

It has lately become fashionable to claim that decoherence has solved the quantum measurement problem by eliminating the necessity for Von Neumann’s wave function collapse postulate. For example…

These striking statements to the contrary, I do not believe that either detailed theoretical calculations or recent experimental results show that decoherence has resolved the difficulties associated with quantum measurement theory.[continued]
http://arxiv.org/abs/quant-ph/0112095

The Role of Decoherence in Quantum Mechanics
http://plato.stanford.edu/entries/qm-decoherence/

[Dmitry67]

Decoherence solves all problems only when coupled with the Multi-world interpretation of course. Multi-world is a consequence of quatum decoherence, not an axiom like in early theories.

The passage from independent probabilities for the states to a single one is not understood yet and this is a dark area that is still under hot discussion.

The above is definitely written by the person who does not believe in many-worlds, so he talks about a 'single one' - not even leaving a room for 2 cats and 2 observers asking 'how the wavefuctions had collapsed into an alive/dead cat???'. These 2 copies of the same observer also claim that QM is random because they can not tell in advance if cat is alive while in fact QM is deterministic

[mgb_phys]

There was once a man who said `God
Must think it exceedingly odd
If he finds that this tree
Continues to be
When there's no one about in the Quad.'

Sir, Your astonishment's odd:
I am always about in the Quad.
And that's why the tree
Will continue to be,
Since observed by Yours faithfully, God.

[DrChinese]

my real question is, does the tree even exist if no one is around?

Welcome to PhysicsForums!

It is generally agreed that the tree exists independently of the act of observation.

However, some observable attributes of the tree - say its color, shape, location - are dependent on the act of observation. This view is not shared by all, but is certainly consistent with experimental evidence. In this view, those attributes are said to be contextual (or non-realistic).

[mn4j]

If a tree falls in the woods...
and no one is around to hear it does it make a sound?...
my real question is, does the tree even exist if no one is around?

Looking at it philosophically:

Let us put your questions in more formal terms. It can therefore be summarized as follows:

1. There exists a tree (T) in the woods
2. The tree (T) falls
3. There is no human around to hear it (T)

Q1. Does T it make a sound?
Q2. Does T exist?

As you can see, The answer of Q2 is obvious, it is one of your premises (1). The tree must exist for your question to make sense.

Now the answer to Q1 is also obvious. It is implied by your third premise. If the tree does not make a sound, then the act of "hearing it" is a logical impossibility which would imply that your third premise is false. Therefore for your question to make sense, the tree must exist and must make a sound when it falls.

Looking at it physically, a falling tree produces vibrations in air molecules and ground molecules within 1000 and 6000Hz, the range of frequencies detectable by human ears (ie sound). So long as molecules are present, they will vibrate. Humans ears hear sound, they do not create sound. The sound must exist for ears to be able to hear them not the reverse. In other words, vibrating air molecules transfer energy to the molecules of the ear-drum which start vibrating as well so the vibrating air molecules must be vibrating BEFORE ear molecules start vibrating.

[Dmitry67]

I am an adept of Multi-Worlds+Quantum Decoherence

When tree falls and you dont know about it, the state of your consciousness is the same no matter if a tree fell or not. So different branches of reality (tree fell or not) can interfere before decoherencing finally in your mind.

[Marcaias]

I am an adept of Multi-Worlds+Quantum Decoherence

When tree falls and you dont know about it, the state of your consciousness is the same no matter if a tree fell or not. So different branches of reality (tree fell or not) can interfere before decoherencing finally in your mind.

If you intend your interpretation to be predictive in the slightest, you still need to apply the usual probabilistic rules of quantum mechanics at some point or you end up simply engaging in philosophical onanism.

And the fact will remain that what you call Nature probabilistically choosing a universe for us to travel down will look exactly like what I call a measurement resulting in collapse.

The latter is also useful. But if practical use is not your concern, there are plenty of string theorists who are all-ears to such ideas.

[olgranpappy]

jeez, way to take the question out of context and make it seem ridiculous. maybe someone else can give a less arrogant answer.
yes

it's not a philosophical question, it's a question about wave function collapses and observation.
no. maybe.

[Renge Ishyo]

This question can easily be run around in circles depending on how "sound" is defined, but in general you can say that a falling tree on earth will produce "sound waves" upon falling even if these waves do not carry to a humans ear for a human to become aware that they were made. Note that this assumes the tree is in an environment/earth where "sound" is produced...if you placed the tree on the moon and it fell it would not make a sound even if an observer was five feet away watching it fall (because there is no medium in space to carry the sound). Some people define "sound" as the sensation we experience only when those sound waves interact with the receptors in our ear drums. In this case, "sound" is not produced if a human is not around because there are no ear drums to receive the waves. And so on. Like much of philosophy these arguments boil down to how sound is defined. Once that is sorted out, you can answer the question reasonably enough.

[Dmitry67]

And the fact will remain that what you call Nature probabilistically choosing a universe for us to travel down will look exactly like what I call a measurement resulting in collapse.


You are misunderstandig the multi-world.
There are many 'us', so we are travelling in all possible paths
But as we remember only the Past, we perceive Time as linear, not like a tree.

If some interpretations include Collapse and others do not, shouldnt we cut the Collapse using occams razor?

Also, if you believe in collapse you need to answer all sorts of questions like 'what exactly makes a measurement apparatus so magical that it causes a collapse while other collections of QM particles do not, deal with a dead/alive cat and Wigners'friend etc.

[mn4j]

If some interpretations include Collapse and others do not, shouldnt we cut the Collapse using occams razor?

"Multi-world" is by itself an extreme violation of Ockham's Razor.

Also, if you believe in collapse you need to answer all sorts of questions like 'what exactly makes a measurement apparatus so magical that it causes a collapse while other collections of QM particles do not, deal with a dead/alive cat and Wigners'friend etc.
Same questions apply to multi-world, What exactly makes a particular decomposition preferred over others in a measurement? In other words, if the cat is alive in one world and dead in another, what causes the observer to perceive one state and not the other on opening the box?

[Dmitry67]

1
"Multi-world" is by itself an extreme violation of Ockham's Razor.

2
Same questions apply to multi-world, What exactly makes a particular decomposition preferred over others in a measurement? In other words, if the cat is alive in one world and dead in another, what causes the observer to perceive one state and not the other on opening the box?

1 Why?
At first, it is not an axiom but a consequence of Quantum Decoherence
I understand that for some reasons it is easy to imagine and to believe into an infinite time or infinite space. But for the infinite number of parralel options is 'weird'.
For some reason, some infinities are much easier to imagine then others.

2 If I understood your question correctly,
As soon as box is opened the observer is decoherenced with a cat. So it splits into 2 copies: one copy observing dead cat, another copy observing a live one. Both copies are asking the same question "what causes me to perceive one state and not the other on opening the box?" :) So the full picture is deterministic.

There are some questions which in fact are not addressed by the Multi-world, but you dont ask them :)

[OrbitalPower]

I think this is something related to Locke's "Primary and Secondary qualities," that the sound is dependent upon the observer. I think physics has incidentally discredited these beliefs.

What if a tree falls and makes a sound and scares some animals? The animals then run toward you in a place where you were unable to hear the sound and thus affecting you in somewhat of an indirect way. We often see animals who are frightened and wonder if maybe they've seen or heard something we didn't notice.

Looking at it physically, a falling tree produces vibrations in air molecules and ground molecules within 1000 and 6000Hz, the range of frequencies detectable by human ears (ie sound). So long as molecules are present, they will vibrate. Humans ears hear sound, they do not create sound. The sound must exist for ears to be able to hear them not the reverse. In other words, vibrating air molecules transfer energy to the molecules of the ear-drum which start vibrating as well so the vibrating air molecules must be vibrating BEFORE ear molecules start vibrating.

I agree completely.

Couldn't you also apply the same logic to color and so on, though?

[Pythagorean]

I think this is something related to Locke's "Primary and Secondary qualities," that the sound is dependent upon the observer. I think physics has incidentally discredited these beliefs.

What if a tree falls and makes a sound and scares some animals? The animals then run toward you in a place where you were unable to hear the sound and thus affecting you in somewhat of an indirect way. We often see animals who are frightened and wonder if maybe they've seen or heard something we didn't notice.



I agree completely.

Couldn't you also apply the same logic to color and so on, though?

somewhat, if you mean in terms of wavelength, but qualitatively what you experience as "red" is mostly something your brain does to interpret, store, and label the information it's getting.

To make the idea more clear, consider tonality and music. As humans we are pretty good at telling tones apart, and whether you're going up a tone, down a tone. You'd be surprised how many people can recognize an octave a short time after hearing their first example of one. Our sense of smell, however is not organized like that (it's not ordered like consecutively ascending tones).

On the other hand, neurologists are finding that canines interpret smells the same way we interpret tones. If we add a hydrogen atom to some arbitrary aromatic, the dog will detect the new molecule as being as some "tone interval" higher (maybe an octave? I don't know the specifics, but the point is they organize the information in the way we organize sound in our brain).

So yeah, there's a buffer between us and reality. Traditionally, we consider wavelength/frequency to be the reality, and "color" to be our interpretation of the reality based on how our brain chooses to codify, recognize, and store information pertaining to visual stimulation.

Conclusive Response to this Thread:

When threads like this come up, it's common to show how we realize that there is a buffer between us and reality that makes it confusing and difficult to understand reality, but it doesn't mean reality only exists when we're around. It's more like our own, personal, skewed versions of reality only exist when we're in the presence of the reality we're skewing.

[epkid08]

and no one is around to hear it does it make a sound?...

my real question is, does the tree even exist if no one is around? and what qualifies an "observer". do wave functions collapse only in the presence of humans? why can't schroedinger's cat tell if it is dead?

I guess I'm asking for a general overview so that I can contribute CORRECT information the next time conversation of this type starts. Nothing worse than asserting incorrect facts about physics, or anything for that matter.

There is a simple answer to this question. It depends on how you define sound. If you define sound as the literal interpretation of sound waves, then no, it doesn't make a sound. If you define sound as literal sound waves, a tangible thing, then yes it does make a sound.

[a2tha3]

Quantum physics suggests that when you aren't looking at an object it doesn't exist, or exists in a vague and undetermined state.

When something falls (yet it doesn't exist) does the nonexistent object make a nonexistent sound?

No.

But if we postulate that the tree does exist, then as the person above me says it depends on how you define sound. It still makes the same frequency, but no one is around for the frequency to interpret it....

[Monaco]

I am an adept of Multi-Worlds+Quantum Decoherence

When tree falls and you dont know about it, the state of your consciousness is the same no matter if a tree fell or not. So different branches of reality (tree fell or not) can interfere before decoherencing finally in your mind.

Ah, but I DO know about these trees falling...

I don't know exactly where they are, what time they fell or what they look like- but I am aware of the theory of trees falling or not falling and my imagination (or whatever it's called) took that into account, recreated and played back that sound in my head! What is the explanation of this phenomena and how is it realative to trees falling or not? Ok, so the ear drum translates sound waves to the brain and we call this hearing. That's great, but I bypassed the middle man and I can still hear it. How in the world is that possible? (If it helps, there were little yellow birds chirping in the background.)

So if a tree falls in my head, bypasses my ears, but I still perceive it, does it make a sound? It would be interesting to know where the sound goes after resonating the ear drum and on what medium they are recorded on. There's also the absense of sound, which sounds to me like a sound all in itself. It sounds like a lot of trees are falling and only hippies can hear them. (btw, i'm not a physician, I'm a musician)

[Monaco]

Quantum physics suggests that when you aren't looking at an object it doesn't exist, or exists in a vague and undetermined state.Quantum physics sounds retarded.
If I'm not looking at a tree, it's not there? That's about as absurd as looking at a nothing and seeing a tree.

Quantum physics puts a lot of weight on sight = existence. I think it's bull. Bats scream at things and paint pictures in their head of where they are. The bat can't see the tree, but it still exists.

[disregardthat]

This philosophical riddle has nothing to do with sound, the question could more generally be asked as "If a tree falls in the forest, and no one is around to sense it, did it fall?". This question is about the nature of existence versus the nature of experience and observation. I.e. how these are concepts are connected. To come with a scientific explanation of sound waves and sound in our brains is completely dodging the point.

[disregardthat]

Quantum physics sounds retarded.
If I'm not looking at a tree, it's not there? That's about as absurd as looking at a nothing and seeing a tree.

There are many aspects of existence which many have illusions of. Such a view as you present is philosophically banal, and modern science no longer supports it (which it never really did. The interpretations of science did however).

[tauon]

my real question is, does the tree even exist if no one is around?

I don't know, go take a look!

[Entropee]

So if a creature with absolutely no self awareness is secluded to an area of relativly empty space, does it exist? Hopefully it does O.o

[Dadface]

Most people would say that common sense tells us that the tree did make a sound,some may argue that it didn't and yet others may describe different scenarios.If the situation is such that absolutely no evidence can be gained then whatever view is taken is unproveable speculation.

[kote]

Let me give a different point of view on this - I actually wrote a philosophy thesis chapter about this question :rolleyes: (the thesis was on QM). Skimping on the sourcing I'll quote the Stanford Encyclopedia of Philosophy entry on the Copenhagen Interpretation:Bohr no longer mentioned descriptions as being complementary, but rather phenomena or information. He introduced the definition of a “phenomenon” as requiring a complete description of the entire experimental arrangement, and he took a phenomenon to be a measurement of the values of either kinematic or dynamic properties.

According to complementarity, it does not make sense to ask if a sound occurs without being heard. This is akin to asking for an electron's position when it isn't interacting with something - it simply doesn't have one. Sound is a type of phenomenon, and as such, can only exist in a complete experimental setup. Sound is subjective. It is how one's mind interprets compression waves in the air. Without a working set of ears and a capable nervous system, you only have compression waves.

Take the question in slightly different context: is an apple red when no one is looking at it? We have been told that color is an extrinsic property. Color requires many things including proper lighting. When we say that an apple is red, what we really mean is that given proper lighting, a person with normal vision will see a red color when looking at the apple. Even in this case, we still have the problem that we have absolutely no idea whether or not we experience the same thing when we claim to be seeing red. Maybe what I see as red appears to you as green. There is no way to tell.

The point is that sound, like color, is a subjective phenomenon that can only manifest given proper experimental conditions. An apple is not red per se, but it has the ability to manifest a red color in my perception given the right circumstances. Likewise, a tree falling does not make a sound per se (although it does make compression waves in the air), but the event of a tree falling has the ability, given the presence of a person with a functioning auditory nervous system, to manifest the perception of a sound in that person.

This, of course, is only a complementarity reading of the question. The answer I gave is philosophically and physically consistent. You could present a similarly philosophically and physically consistent answer which says that the tree does make a sound. Our physics is not so well defined regarding quantum mechanics that we can answer the question definitively. The real answer to the question is that it depends on your assumptions. A deeper understanding of which assumptions are at play and the other implications they have requires more study of QM. I believe Neils Bohr, however, would have answered your question in the negative - no sound is made.

[BobG]

Take the question in slightly different context: is an apple red when no one is looking at it? We have been told that color is an extrinsic property. Color requires many things including proper lighting. When we say that an apple is red, what we really mean is that given proper lighting, a person with normal vision will see a red color when looking at the apple. Even in this case, we still have the problem that we have absolutely no idea whether or not we experience the same thing when we claim to be seeing red. Maybe what I see as red appears to you as green. There is no way to tell.

The point is that sound, like color, is a subjective phenomenon that can only manifest given proper experimental conditions. An apple is not red per se, but it has the ability to manifest a red color in my perception given the right circumstances. Likewise, a tree falling does not make a sound per se (although it does make compression waves in the air), but the event of a tree falling has the ability, given the presence of a person with a functioning auditory nervous system, to manifest the perception of a sound in that person.


Given that the apple doesn't generate enough visual light for a person to see, but that it reflects primarily red light while absorbing other colors, is the apple still red when it's sitting in a dark room? Is it still emitting infrared light even though a human is in the room instead of a snake? Is the apple still sitting on the table even though only the bat in the room can detect the sonar signals bouncing off of it?

Worded this way, I think the first question is better than the "If a tree falls in the woods..." question. The second and third would be equivalent, except with a snake and a bat substituted for a human. Those compression waves will have an effect on the tree's surrounding environment whether a human is the observer or something else is the observer. I guess I don't have a huge conceptual conflict with the original question, but setting up a situation where the sound doesn't exist winds up becoming too ludicrous to take seriously.

In fact, with the proper sensor and a substituting visual colors for infrared frequencies, the exact same info a snake receives can be received by a human, even if it takes a little work. Sure the hot spots aren't really red and the cool spots aren't really blue, but the relevant info has been passed none the less.

[kote]

Given that the apple doesn't generate enough visual light for a person to see, but that it reflects primarily red light while absorbing other colors, is the apple still red when it's sitting in a dark room? Is it still emitting infrared light even though a human is in the room instead of a snake? Is the apple still sitting on the table even though only the bat in the room can detect the sonar signals bouncing off of it?

Using the framework I described above (primarily Bohr's), no, an apple is not red (how it's normally meant) when sitting in a dark room. In fact, an apple is not red at all. Saying that an apple is red is a linguistic simplification when the situation really is that an apple has the ability to manifest the sensation of a red color in the mind of a proper observer. It's extrinsic vs intrinsic. Subjective perceptions, regardless of their connection with physical events, are conceptually nonphysical things. Hot or cold, colorful or grayscale, loud or silent - these are not objective properties of things or events. They each depend absolutely on the particular nervous system of their observer (among other factors).

Is an apple red? Ask my colorblind uncle. Did the tree make a noise? Ask my deaf brother. Etc. These things are very distinct from the underlying physical situations involving relative mean kinetic energy, relative electromagnetic frequency intensities, and potential compression waves. Setting up situations where particular expected perceptions are not realized is quite easy, and I've just listed a few. I don't agree that it is ludicrous.

With regard to snakes or bats, what reason do you have to think that any snake has ever seen red? In fact, "What is it like to be a bat? (http://www.clarku.edu/students/philosophyclub/docs/nagel.pdf)" I never claimed that a bat could not detect an apple. I claim that, given Bohr's assumptions, a bat does not see the red of an apple that I see. Red is a perception that the apple manifests in me but not the bat. It is not an intrinsic objective property of the apple but rather an ability that the apple has when I'm around.

Conceptually, the only relevant difference between colors and sounds are that colors typically belong to objects and sounds typically belong to events - that's why philosophically it's often easier to consider colors. As perceptions though, neither can exist without a subjective observer. I don't think this is where the situation gets tricky. We're simply discussing classically extrinsic properties.

Where QM comes into play is that experiments have shown us that location, momentum, polarization, etc, have no higher ontological standing than color, sound, or even meaning. Classically we have a distinction between the perception of red and the frequency of the EM waves. QM shows us that the properties of EM waves are just as context dependent and complementary as the subjective perception of color is. QM shows that position and mass are not, in fact intrinsic and persistent properties of an electron. We've proven that an electron does not always have a defined position or mass, and that the property that manifests itself depends explicitly on the context of the measurement.

This is where the stuff hits the fan. We had no problem with extrinsic properties before, but now we realize that every classical property is extrinsic. So we have two choices here. We can accept this fact, as Bohr did. We can say that extrinsic properties are fully real and there is no underlying intrinsic (hidden variable) level of reality. I prefer this view. It allows us to say that color, sound, and the meaning of these words are just as real as position and mass. Understanding that all properties are in fact context dependent also allows Bohr to consistently say things like "the apple is real" with it being understood that a red apple cannot exist in a (metaphorical) vacuum and the apple is not red in all situations.

The other option is to go Bohm's route and deny that sound, color, mass, position, or polarization are basic and real properties. We can claim that there is some underlying and yet unknown explanation using properties we have no conception of. According to Bohm's view, yes a sound is made, but sound is not real, it is a macroscopic approximation of the real properties at play. Bohm went as far as to say that there is an infinite regress of deeper layers of complexity and that we cannot in principle ever truly speak of real things since they are unknowable. I prefer not to let solipsistic epistemological issues destroy any hope of a true ontology, but this is an aesthetic choice. Both options seem to be consistent with logic and experiments.

Woah, sorry for the length! Sometimes philosophy needs it, and the intelligent reply got me going :smile:.

[BobG]

Did the tree make a noise? Ask my deaf brother.

That would be a good idea. Sound waves travel through other media besides air. Your deaf brother could well sense the sound of the tree falling even if he doesn't perceive sound the same way a hearing person would.

The same idea behind a human observing infrared light with an infrared sensor and artificially translating different infrared frequencies to visual light frequencies.

Is it the method in which the info is interpreted that's important or is it the information that's important?

The color of the apple in a dark room affects the actual information, not just a difference in how the info is received and processed. (In the case of colorblindness, a sensor that would translate the affected frequencies to a different frequency could be used similar to the infrared frequencies - the info is still there.)

If the process of hearing is more important than the information received by hearing, then, "No", there is no sound if there's no human to receive it, there's no sound if the human didn't bring his dog with him (since the dog will hear some frequencies from the fall that the human is incapable of hearing), etc.

If the information transmitted by the sound is more important, then, "Yes", there is sound as long as the sound energy exists and there is something, anything, living or inanimate, to receive and be affected by the information.

[kote]

That would be a good idea. Sound waves travel through other media besides air. Your deaf brother could well sense the sound of the tree falling even if he doesn't perceive sound the same way a hearing person would.

The same idea behind a human observing infrared light with an infrared sensor and artificially translating different infrared frequencies to visual light frequencies.

Is it the method in which the info is interpreted that's important or is it the information that's important?

The color of the apple in a dark room affects the actual information, not just a difference in how the info is received and processed. (In the case of colorblindness, a sensor that would translate the affected frequencies to a different frequency could be used similar to the infrared frequencies - the info is still there.)

If the process of hearing is more important than the information received by hearing, then, "No", there is no sound if there's no human to receive it, there's no sound if the human didn't bring his dog with him (since the dog will hear some frequencies from the fall that the human is incapable of hearing), etc.

If the information transmitted by the sound is more important, then, "Yes", there is sound as long as the sound energy exists and there is something, anything, living or inanimate, to receive and be affected by the information.

Except I've already made a distinction between sound (the sensation) and compression waves :smile:. That's why it's usually easier to concentrate on color. A deaf person can sense compression waves and tell you that you probably would have heard something had you been there, but that's not the same as hearing. It's similar to a colorblind person telling you a stop sign is red.

It's amazing how one's interpretation of QM is intimately entangled with one's philosophy of mind. Physics, of course, is only concerned with "information" conveyed by experiments, but this avoids Chalmers' hard problem of qualia. It ignores the subjective. There is a difference between pretending to perceive something and actually experiencing it.

I believe that there is something that it is like to be me. I'm not just an empty machine reporting on colors and sounds. I have a real subjective existence in which the color red exists independently of (though usually caused by) EM waves. I have more information when I perceive a red stop sign than the colorblind man who is told the sign is red. This leads me, as discussed, to saying that the tree doesn't make a sound.

To accept that the tree does make a sound, which you can do, you must also accept that a colorblind person who is told all of the details about the color of a sign has just as much information as someone who actually sees it, which you might also do. I claim that he will always lack knowledge of what it is like to perceive a red sign.

[kote]

Our last two posts said very similar things I think. To sum up, I'll say that communication is necessarily lossy when it comes to subjective experience. The best we can do when communicating experience is to use analogy. The best Merriam-Webster can do for "red" is "being in the color range between a moderate orange and russet or bay." When pressed for a definition that doesn't reference other colors you would have to say something like, "red is the color of a stop sign."

There is no possible communicable definition of red that is not circular. Red can only be known by direct experience and talked about by analogy. Unless, of course, you are satisfied that the dictionary definition of red is complete and blind people can know red as well as I can.

[Coldcall]

I'd like to add an alternative to the interpretations posted so far re: "does the tree make a sound".

We seem to forget that everything on earth is entangled through interactions and shared experiences. Just because the human is not around to witness the sound of the tree falling does not mean it did not make a sound. However that sound if not heard by a human, certainly does not make the sort of sound a human would expect from a falling tree. The local observers, being insects, birds or whatever other biology in proximity to the falling tree would experience their own version of what "sound" occured. It migh not have anything to do with sound, but it would notice something has changed.

So that tree cannot make a "sound" as we know it, without a human with ears to witness the event. This is a basic fact.

If one takes an observer-centric view of qm (as i certainly do) then the question is defining what constitutes an observer able to collapse a wavefunction. In my view all biology qualify as observers simply because they have a) sensors b) information processing abilities.

So the tree might make a noise but not one would we identify as a tree falling. Does an ant have human-like ears? No, of course not. So the sound or vibrations it would experience are not the same as ours.

Hence the tree did not make a noise as we understand it, because without human ears nearby to witness the event, the tree falling noise has not entered our consciousness, other than after the fact when we get to the forest and see a fallen tree. We may be able to imagine what it sounded like falling, but no human witnessed the event.

The event happened according to all the biology which was present at the time but we have no right to say it made a "noise" as we know it.

[JRDunassigned]

Could one not simply put a sound and visual recording device in the forest?

Nobody is around to see it, yet when they recover the data, it will be there.

[Evo]

Could one not simply put a sound and visual recording device in the forest?

Nobody is around to see it, yet when they recover the data, it will be there.That would be the simple solution to prove that it does make a sound, that can be captured, absent of all life, and then replayed. When this question first came up, no such equipment existed.

But my youngest daughter, that likes philosophy, keeps telling me that's not the point of the "exercise" it's supposed to make you think differently, or something. I stop listening to her when she goes into "philosphic mode". People have been arguing this forever and to no point.

[Q_Goest]

Hi Evo,
That would be the simple solution to prove that it does make a sound, that can be captured, absent of all life, and then replayed. When this question first came up, no such equipment existed.

But my youngest daughter, that likes philosophy, keeps telling me that's not the point of the "exercise" it's supposed to make you think differently, or something. I stop listening to her when she goes into "philosphic mode". People have been arguing this forever and to no point.
I'm afraid your daughter is correct... <sorry> There really is a point to this exercise, and the word "exercise" is a pretty good way of describing it. The point is to consider a phenomenon which occurs inside your head. That phenomenon is the phenomenon of qualia, also called "subjective experience". As we've already seen in this thread, explaining what this phenomenon is all about is very difficult to get across, even to scientific advisors. <sorry BobG, don't mean to pick on you> Qualia is a phenomenon which occurs inside a human brain. It isn't something that occurs outside of a brain as near as we can tell. So the point about there not being any sound if no one is around regards this strange phenomenon called qualia.

To explain what this phenomenon is, I think I have to agree with kote here:
Except I've already made a distinction between sound (the sensation) and compression waves :smile:. That's why it's usually easier to concentrate on color.
The exercise as applied to sound waves is a bit more difficult to gasp for all the reasons kote provided. Consider color instead. Does a red stop sign have any physical property that is red? Certainly the stop sign has measurable, physical properties and amoung these properties are the various wavelengths of light that are reflected off the sign and enter your eye. The spectrum of light that your eye absorbs contains photons across a broad range of wavelengths. We can measure the wavelengths and frequency of the light. We can measure the intensity or amplitude. But does that spectrum of light that your eye absorbs also contain the measurable properties of red? The very simple answer (or is it a complicated answer?) is no.

I'm sure you know all this except perhaps for the punchline, but for the sake of clarity, I want to go through how the phenomenon we call qualia come about in the brain. If you look at what your body does with this wavelength of light, it first has some cones in the back of your eye that have chemicals inside that react with specific wavelengths of light. Those cones are actually a type of neuron, and they can transmit a type of chemical/electrical signal (ions) to their neighboring neurons. Those neurons recieve numerous signals such as these from various other cones and perhaps other neurons as well. These neurons pass that signal along depending on now the neurons are wired together and how many signals they recieve. So really, there is no light being passed along, it is just neurons passing those signals along through your brain. The signals go from your eye back into various parts of your brain and bounce around and your brain creates a phenomenon from all these signals that we understand as color. Color is a "subjective experience" because it is the experience we have when light of a given wavelength interacts with the cones in our eyes. If we had a different number of cones, such as bees or birds have (they have 4 different cones instead of the 3 humans have) then we would presumably experience different colors, because birds and bees can distinguish the difference between various spectrums of light that we humans can't. Is this to say that humans can't experience the 'actual' color? nope... because there is no 'actual' color. Color is a phenomenon that is created by the brain, it isn't a property of the light itself. In other words, these things we experience are called qualia, and they are representative of the real world, but they are not the real world itself. They only represent the world for us humans, and if we were Martians or birds, with different genes and different senses, we would experience the world in a very different way. We might consider for example, what our subjective experiences would be like if we were some other animal or intellegent species. Those subjective experiences (qualia) would likely be very different, but just as useful in representing the world for us.

Similarly, the noise we hear isn't a property of the compressed air waves. The noise we experience is a subjective experience that exists only inside our heads. It isn't a property of the air at all. Sure we can record it and play it back and it sounds the same, but that's not because the properties of the phenomenon we experience inside our head (called qualia) is being recorded. What is recorded is a symbolic representation (digital or analog) of the sound waves that can be converted back into sound waves using a speaker which vibrates the air in exactly the same way that the air vibrated a microphone. The point is that if a tree falls in the woods and there's no one around to experience it, then yes it creates the same vibrations in the air that it would had someone been standing there. But the whoosh and the crash that our brains create would not exist and would not be created by the falling tree.

[Evo]

Hi Evo,

I'm afraid your daughter is correct... <sorry> There really is a point to this exercise, and the word "exercise" is a pretty good way of describing it. True. She is quite advanced in philosophy, although she was devasted when she entered college. She had such a great philosophy teacher in high school, that she was ecstatic about taking philosophy in University. Her professor in philosophy at her university was so bad, that she actually withdrew. She was devasted. She thought that she would get deeper into it, and instead it was a huge step back.

[JRDunassigned]

True. She is quite advanced in philosophy, although she was devasted when she entered college. She had such a great philosophy teacher in high school, that she was ecstatic about taking philosophy in University. Her professor in philosophy at her university was so bad, that she actually withdrew. She was devasted. She thought that she would get deeper into it, and instead it was a huge step back.

This is the strange state of American University, and a common phenomena across various fields of study. Education needs an overhaul.

But back to the point, I think this little argument about the true creates a hole of thought that questions whether or not philosophy and physics can exist when taken to their greatest lengths - they seem to differentiate so far apart that it conjures images of science as a whole and religion as a whole, beating each other up.

[Q_Goest]

True. She is quite advanced in philosophy, although she was devasted when she entered college. She had such a great philosophy teacher in high school, that she was ecstatic about taking philosophy in University. Her professor in philosophy at her university was so bad, that she actually withdrew. She was devasted. She thought that she would get deeper into it, and instead it was a huge step back.
wow... sorry to hear that. What university is she going to? Curious to see what the staff looks like there.

I'd think if she really liked philosophy that much she could find a university she enjoyed though. Perhaps it has to do with the views expressed by the prof? I could definately see that happening, I'd quit myself if I had to listen to Dennett. <blah!>

[Evo]

wow... sorry to hear that. What university is she going to? Curious to see what the staff looks like there.

I'd think if she really liked philosophy that much she could find a university she enjoyed though. Perhaps it has to do with the views expressed by the prof? I could definately see that happening, I'd quit myself if I had to listen to Dennett. <blah!>It was quite devastating to her.

But she was accepted pre-med, so she moved on, although I am NOT allowed to discuss philosphy because I am too black and white.

[SDetection]

If a tree falls in the woods...and no one is around to hear it does it make a sound?...
Of course not. It wouldn't make a sound in any one's head :wink:.

[WaveJumper]

What is a 'tree' before measurement/observation? Waves of probability? Or waves of substance? The measurement problem is inextricably connected with the answer to the question - If a tree falls in the woods, does it make a sound?

[SDetection]

What is a 'tree' before measurement/observation?

Note that the tree is already observed by the earth, and the earth is observed by the tree, and the earth is observing us, the moon, the sun, the galaxy...

[WaveJumper]

Note that the tree is already observed by the earth, and the earth is observed by the tree, and the earth is observing us, the moon, the sun, the galaxy...


This says nothing about the system before going from a superpositional state to a mixed state.

[SDetection]

This says nothing about the system before going from a superpositional state to a mixed state.

I'm not good at physics, but is there a tree that exists in superpositional state?, or you mean an imaginary tree?.

Also I think the measurement/observation depends also on the observer. When you touch a tree that you're looking at, you still observing the same tree but from different perspectives. The same situation applies if you use an infrared camera. The perspectives can change but the dimensional knowledge obtained is from the the same thing.

[WaveJumper]

I'm not good at physics, but is there a tree that exists in superpositional state?, or you mean an imaginary tree?


No, not just a tree or a bush. The whole of reality is depicted by wavefunctions, describing probability amplitudes of localising 'particles'. What those wavefunctions represent is the core of the argument - If a tree falls in the...

There are good reasons to believe they aren't real and are just a mathematical tool(objective reality does not exist), but there are also reasons to believe there is more going on than mathematics before a measurement(debate is still ongoing). Otherwise, the tree exists as a probability wavefunction that sort of maps out around the tree(soaks into the space around the tree - a sort of blurred image of a tree if you need a mental image).

The wavefunction accounts for everything that we can measure, so it is obviously linked to what we call 'physical reality'. How else could QM be relevant for physical properties and phenomena?

An unbiased treatment of the problem of objective reality in the 20th and 21st century, requires that it is treated by physics as a hypothesis that needs to be proved.


Also I think the measurement/observation depends the observer. When you touch a tree that you're looking at, you still observing the same tree but from different perspectives. The same situation applies if you use infrared camera. The perspectives can change but the dimensional knowledge obtained is the same.


I don't see what you are saying here.

[SDetection]

I don't see what you are saying here.
I mean, the mechanism, that you use for the observation, also determines your final perception of the observed. There can be different perspectives of the same thing, like when you use your eyes, and when using an infrared camera. This is of course from classical point of view...

[SDetection]

Of course not. It wouldn't make a sound inside any one's head.

But of course nature would hear it, in its own mysterious way :cool:.

[baywax]

Existence is relative to the observer? If the tree doesn't exist because you don't see it nor measure it etc... then the dust mites in your eye lashes don't exist either. This seems a bit egocentric to believe. Why not step out of the box and allow for phenomena to exist without your permission?

[WaveJumper]

Existence is relative to the observer? If the tree doesn't exist because you don't see it nor measure it etc... then the dust mites in your eye lashes don't exist either. This seems a bit egocentric to believe. Why not step out of the box and allow for phenomena to exist without your permission?


Every physicist asks this question sooner or later. Some are asking themselves to their dying day, some consider it only as a passing thought and dismiss it as an issue that cannot be resolved. Others are afraid to even look in that direction and will frantically move onto the next topic.

I believe a problem should be approached without bias. The biggest missing link towards having a better understanding of reality, imo, currently resides in the notion of Time(on top of other foundational problems). We have different concepts of time in classical mechanics, in GR and in QM and time is a fundamental ingredient in what we call 'reality'. Without some new insight into its nature, this 'reality' may remain unknowable for quite some time. If time is strictly a macroscopic phenomenon, then we have no basis to insist on space being objectively real either. There is likely something 'wrong' with our perception of the notions - matter, time and space and the hypothetical TOE will supposedly adjust these 'misunderstandings'. Afterall, the theory of evolution doesn't claim our senses evolved for the purpose of verifying quantum mechanics, so we can't blame our senses for being too coarse to discern how reality operates at its fundamental level.

To wrap this up, there are good reasons to believe that the notion of "real" and "reality" needs re-adjusting in a moderate or a rather radical way. Those reasons all come from cosmology, quantum theory and GR. The only field from physics that supports all our naive assumptions about reality, is classical newtonian physics where it appears the environment had wired our brains to operate within that domain.

I don't see a reason to believe that either matter, or space might have a fundamental status. Both those concepts are securely tied to the dynamical background of GR. There doesn't appear to be a way to uphold the naive assumptions of our perception. What we term reality is either a limited, special case of what exists out there, or likely it's only just perception(with all the philosophical implications arising from this).

[baywax]

Every physicist asks this question sooner or later. Some are asking themselves to their dying day, some consider it only as a passing thought and dismiss it as an issue that cannot be resolved. Others are afraid to even look in that direction and will frantically move onto the next topic.

I believe a problem should be approached without bias. The biggest missing link towards having a better understanding of reality, imo, currently resides in the notion of Time(on top of other foundational problems). We have different concepts of time in classical mechanics, in GR and in QM and time is a fundamental ingredient in what we call 'reality'. Without some new insight into its nature, this 'reality' may remain unknowable for quite some time. If time is strictly a macroscopic phenomenon, then we have no basis to insist on space being objectively real either. There is likely something 'wrong' with our perception of the notions - matter, time and space and the hypothetical TOE will supposedly adjust these 'misunderstandings'. Afterall, the theory of evolution doesn't claim our senses evolved for the purpose of verifying quantum mechanics, so we can't blame our senses for being too coarse to discern how reality operates at its fundamental level.

To wrap this up, there are good reasons to believe that the notion of "real" and "reality" needs re-adjusting in a moderate or a rather radical way. Those reasons all come from cosmology, quantum theory and GR. The only field from physics that supports all our naive assumptions about reality, is classical newtonian physics where it appears the environment had wired our brains to operate within that domain.

I don't see a reason to believe that either matter, or space might have a fundamental status. Both those concepts are securely tied to the dynamical background of GR. There doesn't appear to be a way to uphold the naive assumptions of our perception. What we term reality is either a limited, special case of what exists out there, or likely it's only just perception(with all the philosophical implications arising from this).

Nice look at the way people either believe the tree exists when they aren't looking or not... etc...

Personally I believe that forewarned is forearmed or whatever the saying is. That way, even if you don't see the tree you are aware that it may be falling on you, and that the results can be crippling or deadly.

The whole "purpose" of our senses for the last 6 million years has been to keep us alive... in a macroscopic world. The senses are honed to that function by evolution and natural selection down through the generations of us. No wonder we're confused when we start catching glimpses of the microscopic. When we are able to discern a cause and effect going on between the two, with the accuracy found in the function of our senses here, in the macroscopic, perhaps things will become clearer. For now, though, I'll remind you that nothing is only a part of everything!

[WaveJumper]

Have the experiments of Benjamin Libet on how unconscious electrical impulses predate conscious volitional acts been repeated or refuted? If not, it might, from a certain perspective, be interpreted as support for the primacy of mind over brain.

[SDetection]

Have the experiments of Benjamin Libet on how unconscious electrical impulses predate conscious volitional acts been repeated or refuted? If not, it might, from a certain perspective, be interpreted as support for the primacy of mind over brain.

Here is a definition of consciousness that doesn't make us special: An entity that is involuntary/unconsciously recalling an aspect, of its prior state, which it involuntary/unconsciously memorized, is conscious in regard to this aspect.

This means that, not because one is unconscious, one can't memorize anything, but one is unconscious because one hasn't just memorized anything to recall. What do you do if you want to wake someone up?
There is, of course, degree of consciousness, which is characterized by the levels of the dimensional knowledge that the observer can abstract from the stimuli, like when someone abstracts speech from sounds, or emotions from faces...

[WaveJumper]

Here is a definition of consciousness that doesn't make us special: An entity that is involuntary/unconsciously recalling an aspect, of its prior state, which it involuntary/unconsciously memorized, is conscious in regard to this aspect.


This doesn't say what consciousness is or if it's 'special'(whatever that means). It's simply a characteristic/feature of consciousness.


This means that, not because one is unconscious, one can't memorize anything, but one is unconscious because one hasn't just memorized anything to recall. What do you do if you want to wake someone up?
There is, of course, degree of consciousness, which is characterized by the levels of the dimensional knowledge that the observer can abstract from the stimuli, like when someone abstracts speech from sound, or emotions from faces...



What is the 'observer' that you seem to take for granted? This is a core issue and i am attempting to validate the assumptions being made, before proceeding to account for macro-scale phenomena. One of the basic assumptions is that matter is real and fundamental. I disagree with the latter and i am doubtful about the former. A thourough look at the nature of matter, space and time doesn't hold up to our pre-conceived notions. In this connection, i said earlier:




I don't see a reason to believe that either matter, or space might have a fundamental status. Both those concepts are securely tied to the dynamical background of GR. There doesn't appear to be a way to uphold the naive assumptions of our perception. What we term reality is either a limited, special case of what exists out there, or likely it's only just perception(with all the philosophical implications arising from this).

[magpies]

Ok so my definition of consciousness...

Consciousness: Being aware. <-- How good is this???

If I had my choice I would say consciousness is consciousness and leave it at that but thats not allowed it seems.

[Dmitry67]

All definitions of consciousness are pure blah blah unless they help to solve the
so called hard problem of Consciousness.

[WaveJumper]

The real question is what is 'woods' in the 'If a tree falls in the woods and there is no one around...'?

It's an unmeasured supperposition of states that we mistake for woods. The Uncertainty principle does not state that two complementary properties cannot exist together; it merely states that we cannot know the two complementary properties simultaneously.

The uncertainty in the behaviour of particles is an extremely important feature of the nature. The form in which objects are manifested to us is the creation of our brain.

I cannot make a definite statement about the physical state of any entity until I make an observation to determine the actual state of that entity. This forces me to keep all the possibilities open and the best I can do is calculate the probability of finding a specific physical state when I make an observation. Schrodinger's equation allows me to calculate these probabilities, but the fact that a measurement/observation is required to 'collapse' the eigenstates to single outcomes is the core of the measurement problem. It's a powerful insight into the nature of reality and our role in it. If one takes modern physics seriously and assumes that human logic is valid and the right tool to describe reality(incredibly important assumption), then we are living in a relational universe.

[baywax]

The real question is what is 'woods' in the 'If a tree falls in the woods and there is no one around...'?

It's an unmeasured supperposition of states that we mistake for woods. The Uncertainty principle does not state that two complementary properties cannot exist together; it merely states that we cannot know the two complementary properties simultaneously.

The uncertainty in the behaviour of particles is an extremely important feature of the nature. The form in which objects are manifested to us is the creation of our brain.

I cannot make a definite statement about the physical state of any entity until I make an observation to determine the actual state of that entity. This forces me to keep all the possibilities open and the best I can do is calculate the probability of finding a specific physical state when I make an observation. Schrodinger's equation allows me to calculate these probabilities, but the fact that a measurement/observation is required to 'collapse' the eigenstates to single outcomes is the core of the measurement problem. It's a powerful insight into the nature of reality and our role in it. If one takes modern physics seriously and assumes that human logic is valid and the right tool to describe reality(incredibly important assumption), then we are living in a relational universe.

Hi Wavejumper, perhaps the macro physical state is too course to "experience" the micro quantum or atomic/electro/magnetic states. Being unaware of a state does in no way prove that one or the other state does or does not exist.

Consciousness is a really bad way of saying "awareness". Somehow its been hijacked by the whoo hoos of the world and is now something you pay money to attain. What it may be trying to convey is the idea that when one is aware of process, causes and effects and the overall picture, they reach a conscious-awareness that is supported by experience and existing, stored knowledge. This way one's experiential awareness is bolstered by a consciousness of facts that add to the experience of the phenomenon. Who knows!!!?

[WaveJumper]

Hi Wavejumper, perhaps the macro physical state is too course to "experience" the micro quantum or atomic/electro/magnetic states. Being unaware of a state does in no way prove that one or the other state does or does not exist.


Hi Baywax,

My stance is not that the quantum doesn't exist, but that the macro scale impression of how matter, time and space exist is either wrong or incomplete. It must have felt similar in the 16th century when Coprnicus tried to get across the message that the hardwired and very intuitive notion of a flat Earth was wrong. The concept of a flat Earth was so intuitive for the primitive human perception that there are today vocal proponents of the flat Earth nonsense.

Consciousness is a really bad way of saying "awareness". Somehow its been hijacked by the whoo hoos of the world and is now something you pay money to attain. What it may be trying to convey is the idea that when one is aware of process, causes and effects and the overall picture, they reach a conscious-awareness that is supported by experience and existing, stored knowledge. This way one's experiential awareness is bolstered by a consciousness of facts that add to the experience of the phenomenon. Who knows!!!?


Maybe it's because we have zero knowledge of the important fundamental concepts. I'd stay away from naive models of reality, though.

[baywax]

Hi Baywax,

My stance is not that the quantum doesn't exist, but that the macro scale impression of how matter, time and space exist is either wrong or incomplete. It must have felt similar in the 16th century when Coprnicus tried to get across the message that the hardwired and very intuitive notion of a flat Earth was wrong. The concept of a flat Earth was so intuitive for the primitive human perception that there are today vocal proponents of the flat Earth nonsense.

Hi WaveyGravy! I have a feeling that if the emergent phenomenon you're calling a macro scale impression of matter didn't exist, we wouldn't be talking about it right now. The other thing about your statement is... is it wrong or right... its neither. When you see green as red its neither wrong or right... its either a trick of simultaneous colour contrast or a trick of the light. There are always mechanisms creating impressions and illusions and they are the subject of our fun inquiries. There's a lot of top physicists who think the universe is flat. That would make earth pretty flat too.

[WaveJumper]

Hi WaveyGravy! I have a feeling that if the emergent phenomenon you're calling a macro scale impression of matter didn't exist, we wouldn't be talking about it right now.

Yes, it probably exists but the fact that we are talking about a consensus event does not mean that the event exists outside our conscious perception in the way it is manifested to us.


The other thing about your statement is... is it wrong or right... its neither. When you see green as red its neither wrong or right... its either a trick of simultaneous colour contrast or a trick of the light. There are always mechanisms creating impressions and illusions and they are the subject of our fun inquiries. There's a lot of top physicists who think the universe is flat. That would make earth pretty flat too.


Sorry, i don't see your point.

[disregardthat]

A little off-topic, but...

WaveJumper, I have a question for you since you obviously knows quite a lot of quantum mechanics. What are your views on the classical interpretations of QM like the "Many-worlds theory" and the "copenhagen interpretation"?

[baywax]

Yes, it probably exists but the fact that we are talking about a consensus event does not mean that the event exists outside our conscious perception in the way it is manifested to us.

That's all we have to go on. This is no indication that the event is not as we perceive it to be. There are countless accounts of artifacts and phenomenon being misinterpreted. Take the canals on Mars for example. There's millions of examples. But, all its taken is advances in technology (in this case telescoping) and concentrated effort to prove a phenomenon is what we think it is or that its something else.




Sorry, i don't see your point.

That doesn't mean it is non-existent...:redface:
I think I was trying to point out that what you see is not always what you get... but that is neither wrong or right nor does it point to the non-existence of a phenomenon.

[WaveJumper]

What are your views on the classical interpretations of QM like the "Many-worlds theory" and the "copenhagen interpretation"?


I have not seen an interpretation that i would embrace as true. There is something fundamentally missing from our knowledge of reality and all these interpretational efforts are kind of premature and incomplete(bordeing on religion). We need a theory of QG and new insights into the nature of space and time, before an interpretation starts to fit the greater picture more convincingly, IMO.

[WaveJumper]

That's all we have to go on. This is no indication that the event is not as we perceive it to be. There are countless accounts of artifacts and phenomenon being misinterpreted. Take the canals on Mars for example. There's millions of examples. But, all its taken is advances in technology (in this case telescoping) and concentrated effort to prove a phenomenon is what we think it is or that its something else.






That doesn't mean it is non-existent...:redface:
I think I was trying to point out that what you see is not always what you get... but that is neither wrong or right nor does it point to the non-existence of a phenomenon.


This is how science works - making conclusions(often wrong) from incomplete evidence. You could say this is what gives us an edge over other animals and lets us predict phenomena and make progress.

[disregardthat]

I have not seen an interpretation that i would embrace as true. There is something fundamentally missing from our knowledge of reality and all these interpretational efforts are kind of premature and incomplete(bordeing on religion). We need a theory of QG and new insights into the nature of space and time, before an interpretation starts to fit the greater picture more convincingly, IMO.

I can agree with you on the Many-worlds theory, but I find the Copenhagen Interpretation to be a rational view.

[Dmitry67]

I can agree with you on the Many-worlds theory, but I find the Copenhagen Interpretation to be a rational view.

Copenhagen? The abandoned one? Ha ha!

[baywax]

This is how science works - making conclusions(often wrong) from incomplete evidence. You could say this is what gives us an edge over other animals and lets us predict phenomena and make progress.

I don't know. Animals make predictions about the kinds of phenomena that might be on the other side of a log before they jump over it. Then they deal with the reality once they hit the other side. They wouldn't be making the leap if they didn't have a fairly good calculation and prediction of what they were jumping into. (We are still in the philosophy section, right?!!)

In fact sometimes we could learn methods of prediction from animals. Here's one possibility.

Earthquake Prediction by Animals: Evolution and Sensory Perception

Joseph L. Kirschvink
Division of Geological and Planetary Sciences
California Institute of Technology 170-25
Pasadena, California 91125
kirschvink@caltech.edu

Manuscript received 13 July 1998.

Animals living within seismically active regions are subjected episodically to intense ground shaking that can kill individuals through burrow collapse, egg destruction, and tsunami action. Although anecdotal and retrospective reports of animal behavior suggest that although many organisms may be able to detect an impending seismic event, no plausible scenario has been presented yet through which accounts for the evolution of such behaviors. The evolutionary mechanism of exaptation can do this in a two-step process. The first step is to evolve a vibration-triggered early warning response which would act in the short time interval between the arrival of P and S waves. Anecdotal evidence suggests this response already exists. Then if precursory stimuli also exist, similar evolutionary processes can link an animal's perception of these stimuli to its P-wave triggered response, yielding an earthquake predictive behavior. A population-genetic model indicates that such a seismic-escape response system can be maintained against random mutations as a result of episodic selection that operates with time scales comparable to that of strong seismic events. Hence, additional understanding of possible earthquake precursors that are presently outside the realm of seismology might be gleaned from the study of animal behavior, sensory physiology, and genetics. A brief review of possible seismic precursors suggests that tilt, hygroreception (humidity), electric, and magnetic sensory systems in animals could be linked into a seismic escape behavioral system. Several testable predictions of this analysis are discussed, and it is recommended that additional magnetic, electrical, tilt, and hygro-sensors be incorporated into dense monitoring networks in seismically active regions.

http://bssa.geoscienceworld.org/cgi/content/abstract/90/2/312

[disregardthat]

Copenhagen? The abandoned one? Ha ha!

"abandoned"?

[Dmitry67]

Yes. MWI is now the #1.
Recently there was a good thread in this forum... damn, I dont remember the title about the CI... nobody here is seriously defending the CI. Anybody, what was the thread title?

[WaveJumper]

I can agree with you on the Many-worlds theory, but I find the Copenhagen Interpretation to be a rational view.


I think the problem with establishing what reality is, lies elsewhere and deeper. If it's about personal beliefs, I think matter, space, and time are as real as the colour 'red' and the solidity of matter, i.e. they are wrong/misleading interpretations of something greater and much different than we've been able to account for so far. Because all the interpretation of the 'outside' reality happens somehow in the brain, and we have no way to directly verify how true and correct that interpretation is(though its consensual), and experiments have been proving time and again that the interpretational mechanism in what is perceived as 'brain' is often flawed, it is necessary to put to test everything that is 'automatically' interpreted as true. The concepts of matter, space and time have failed to stand to the test of our perception so far.

I'd say that I believe only fields exist and some kind of awareness that turns those dynamical fields into an interpreted classical reality - the netbook i hold in my lap, the room i am in, the planet we are on, ... it's all interpretation in my head. Wrong at that. My perspective is that we shouldn't ascribe too much importance to automatic interpretations. It is the task of science to establish the truthfulness of the perceptions and the interpretations. So far, there have been far too many experiments that contradict our in-built interpretations of what exists out there, to continue to hold onto what is termed 'realism'. What interests me most is what lies behind the interpretation of matter, space and time. What are the fields, what are they made from and what is the awareness that generates for me the often contradictory reality we perceive as classical?

We won't account for consciousness with a flawed version/interpretation of what's out there. Ever. And this consciousness/awareness being the interpretor of the supposed outside reality of fields, is IMO a contributor to the paradoxes and a possible solution to foundational problems in physics - time running only in one direction, time flowing, distance between objects(locality vs non-locality), localised objects, all the weirdness of QM, somethings out of nothings, etc. i think are flaws of our interpretation of what's out there. The macro world of fixed, immutable objects in space is a mirage, a phantasm created by awareness that we seem to be. This is somewhat inline with Wheeler's participatory universe, but it deviates on some other important points.

[disregardthat]

The copenhagen interpretion is not a realist view at all. It is actually quite similar to an instrumentalist view (purely pragmatic). It says only about how we should/can interpret the information given, not what the information says about some external world. One of its main points is the focus on how our consciousness can comprehend the world and understand observations. Of course the interpretation is not definite, it is a view under constant change, but it's main points are somewhat like I can agree with. The changes of it are for the better I think. It is very similar to a Kantian perspective.

The many-worlds theory is a realist and deterministic view however, and I don't find it appealing at all.

It doesn't matter what most scientists subscribe to:uhh: That the many-worlds theory is the most popular one is irrelevant. It is not at all "abandoned", many scientists still subscribe to CI.

[WaveJumper]

In 20, 50 or 100 years the people who believe in realism(objects having definite existence in space) will be able to cramp into a mid-size car.

[disregardthat]

In 20, 50 or 100 years the people who believe in realism(objects having definite existence in space) will be able to cramp into a mid-size car.

What? :confused: :approve:

[WaveJumper]

What? :confused: :approve:

How many people can board a mid-size car?

[disregardthat]

How many people can board a mid-size car?

I won't participate in your games

[WaveJumper]

In 20, 50 or 100 years the people who believe in realism(objects having definite existence in space) will be able to cramp into a mid-size car.


...is the same as saying:

"In 20, 50 or 100 years the people who believe in realism(objects having definite existence in space) will be 4 or 5", i.e. they will fit into a mid-size car.

[disregardthat]

...is the same as saying:

"In 20, 50 or 100 years the people who believe in realism(objects having definite existence in space) will be 4 or 5", i.e. they will fit into a mid-size car.

I doubt it. Realism is a persistent view.

You said something like "matter, space and time is a real as the color red". I don't agree with this. It is not that matter, space and time are "things" beyond human recognition, but that they are fundamental to human experience. Kant argued that we cannot transcend the notion of time and space in our experience, not even in our concepts. Hence a copenhagen-like perspective. I'm not talking about an external reality (which we cannot speak of), but the basis of human conception and perception. The color red differs from the concepts of space and time because color is not a necessary form in which perception and conception must take.

[WaveJumper]

I doubt it. Realism is a persistent view.

You said something like "matter, space and time is a real as the color red". I don't agree with this. It is not that matter, space and time are "things" beyond human recognition, but that they are fundamental to human experience. Kant argued that we cannot transcend the notion of time and space in our experience, not even in our concepts. Hence a copenhagen-like perspective. I'm not talking about an external reality (which we cannot speak of), but the basis of human conception and perception. The color red differs from the concepts of space and time because color is not a necessary form in which perception and conception must take.


I didn't say colour red was matter or space. I meant that their reality is comparable, i.e. they are interpretations of the inteactions of quantum fields(as best as we can tell) by the interpreting mechanism inside your head.

[disregardthat]

I didn't say colour red was matter or space. I meant that their reality is comparable, i.e. they are interpretations of the inteactions of quantum fields(as best as we can tell) by the interpreting mechanism inside your head.

That's not what I meant. Red differs in essence form time and space is perhaps wording myself better. The point is the time and space are forms in which experience and conception must take, whereas color isn't. They differ in this way, not in terms of equality. Time and space are also interpretations (and forms of conception) in our brain, but this doesn't mean they don't function as parts of the fundamental structure conception and interpretation of experience must have.

[baywax]

I doubt it. Realism is a persistent view.

You said something like "matter, space and time is a real as the color red". I don't agree with this. It is not that matter, space and time are "things" beyond human recognition, but that they are fundamental to human experience. Kant argued that we cannot transcend the notion of time and space in our experience, not even in our concepts. Hence a copenhagen-like perspective. I'm not talking about an external reality (which we cannot speak of), but the basis of human conception and perception. The color red differs from the concepts of space and time because color is not a necessary form in which perception and conception must take.

It is possible that realism, abstraction and conceptualism along with the rest of the schools of thought exist... that is, actually exist, along side each other. In this way "many worlds" would make sense.

If we didn't have a concept like matter, air, organisms etc... we would not have concepts and so we would not be discussing any of the differences between wave function and solid matter.

Briefly about red... with out the colour red plants would simply grow indefinitely. Its the red spectrum of the sun that triggers the reproductive cycle in many plants and we get flowers and something to harvest out of this.

It seems to me that people are too busy looking for one component to existence instead of taking all the components and using them to construct a congruent and interconnected model of reality... or whatever you want to call it.

[Entropee]

Things are only real because we tell ourselves they are. The world is always as it should be because we instigate it with life by talking to ourselves.

[disregardthat]

It is possible that realism, abstraction and conceptualism along with the rest of the schools of thought exist... that is, actually exist, along side each other. In this way "many worlds" would make sense.

If we didn't have a concept like matter, air, organisms etc... we would not have concepts and so we would not be discussing any of the differences between wave function and solid matter.

Briefly about red... with out the colour red plants would simply grow indefinitely. Its the red spectrum of the sun that triggers the reproductive cycle in many plants and we get flowers and something to harvest out of this.

It seems to me that people are too busy looking for one component to existence instead of taking all the components and using them to construct a congruent and interconnected model of reality... or whatever you want to call it.

Yes, realism might be true. But it is no reason to assume such an absurd thing when we know that our brains structures perception. Realism is not a necessary view.

I think what wavejumper meant about red was the subjective interpretation of the wavelength which we correspond to the color red, not the photons themselves.

[baywax]

Yes, realism might be true. But it is no reason to assume such an absurd thing when we know that our brains structures perception. Realism is not a necessary view.

If what you're saying here is true... and real... then you're not really being real and why would anyone believe what you say.

This makes realism real in the sense that it has to be true in order to make a statement like that in the first place.

[disregardthat]

If what you're saying here is true... and real... then you're not really being real and why would anyone believe what you say.

This makes realism real in the sense that it has to be true in order to make a statement like that in the first place.

Not in any way.

[baywax]

Not in any way.

Is that a real defense or a product of your deluded senses?

[disregardthat]

Is that a real defense or a product of your deluded senses?

Am I supposed to defend against this:

"If what you're saying here is true... and real... then you're not really being real and why would anyone believe what you say."
?

That's nonsense.

[baywax]

Am I supposed to defend against this:

"If what you're saying here is true... and real... then you're not really being real and why would anyone believe what you say."
?

That's nonsense.

When you deny realism exists everything is nonsense.

[disregardthat]

That's just not true.

[Galteeth]

To bring this back down to earth a bit:

Does the tree make a sound? No, a sound is a perception of the brain that in absence of a brain does not occur (let's assume for the sake of agument there are no birds or other brains to hear the sound)

Does the falling tree produce sound waves? Yes, and these will have an effect on the surrouding environment that in principle could be measured.

What about all this quantum business? From my understanding, if the tree does in fact fall in the forest, the odds of it not producing sound waves are so astronomically low that you don't really have to worry about that. This system is going to be descripable classcally.

[baywax]

To bring this back down to earth a bit:

Does the tree make a sound? No, a sound is a perception of the brain that in absence of a brain does not occur (let's assume for the sake of agument there are no birds or other brains to hear the sound)

Does the falling tree produce sound waves? Yes, and these will have an effect on the surrouding environment that in principle could be measured.

What about all this quantum business? From my understanding, if the tree does in fact fall in the forest, the odds of it not producing sound waves are so astronomically low that you don't really have to worry about that. This system is going to be descripable classcally.

Are sound waves an emergent phenomenon of a quantum state? Is a sound wave a macro or micro event?

[Descartz2000]

and no one is around to hear it does it make a sound?...

my real question is, does the tree even exist if no one is around? and what qualifies an "observer". do wave functions collapse only in the presence of humans? why can't schroedinger's cat tell if it is dead?

I guess I'm asking for a general overview so that I can contribute CORRECT information the next time conversation of this type starts. Nothing worse than asserting incorrect facts about physics, or anything for that matter.

Technically yes the tree does exist if no one is around. But, it is insignificant as it takes a conscious observer to identify the tree as separate from its surroundings, It exists all along, but it is meaningless without an observer. An observer can make sense of it after, but prior to being observed there is no one to label and determine that it is even a tree. To separate an object from its surroundings is a conceptualization that requires a brain and its processes of identification. But yes, technically it does exist in the general sense.

[ValenceE]

Hello all,

baywax, you ask;

Are sound waves an emergent phenomenon of a quantum state? Is a sound wave a macro or micro event?


Of course a sound wave is macro from micro… it’s source is the resultant of all micro interactions between the external energetic shell of the tree’s bark, making its way between the surrounding air molecules, with every external energetic shell of any and all ‘things’ that it will interact with as it falls down.

The complexity and amplitude of the wave front strengthens as the falling tree interacts more and more until it comes to a standstill.

No sense of hearing around to hear it… no sound, just a bunch of energetic interactions.

There is a sense of hearing around to hear it… then the macro becomes micro again through the vibrating eardrum which, in turn, triggers the entire resolution/recognition process that makes it a ‘sound’.

Regards,

VE

[baywax]

Hello all,

baywax, you ask;




Of course a sound wave is macro from micro… it’s source is the resultant of all micro interactions between the external energetic shell of the tree’s bark, making its way between the surrounding air molecules, with every external energetic shell of any and all ‘things’ that it will interact with as it falls down.

The complexity and amplitude of the wave front strengthens as the falling tree interacts more and more until it comes to a standstill.

No sense of hearing around to hear it… no sound, just a bunch of energetic interactions.

There is a sense of hearing around to hear it… then the macro becomes micro again through the vibrating eardrum which, in turn, triggers the entire resolution/recognition process that makes it a ‘sound’.

Regards,

VE

Many thanks valence .... how does neuronal interaction with the stipes and hammer of the ear make the sound wave micro?

[baywax]

Technically yes the tree does exist if no one is around. But, it is insignificant as it takes a conscious observer to identify the tree as separate from its surroundings, It exists all along, but it is meaningless without an observer. An observer can make sense of it after, but prior to being observed there is no one to label and determine that it is even a tree. To separate an object from its surroundings is a conceptualization that requires a brain and its processes of identification. But yes, technically it does exist in the general sense.

Perhaps the observer needs the tree and the sound to be considered existent. Perhaps the observer is "meaningless" without interaction of some sort.

Please define "meaningless"/:confused:

[ValenceE]

Many thanks valence .... how does neuronal interaction with the stipes and hammer of the ear make the sound wave micro?



Please baywax, you know better than ask me that question…


VE

[baywax]

Please baywax, you know better than ask me that question…


VE

Well, I don't think it would return to any micro state just because of a few neurotransmitters translating vibration as a sound.

Sound is defined as "vibrations that travel through the air or another medium". So, when the tree falls... and perhaps here we can think of it as its own observer when you consider the research showing the response ability of plants to any kind of vibration or photo stimulus...

ABSTRACT
The effects of sound and music on plant growth have been an intriguing subject and
the fascination of many a horticulturist over the years . Many have claimed the effects of
talking or the playing of classical music to the plants . Surprisingly, this has some scientific
basis, according to research done mainly by the scientists from China and Japan .

http://sps.nus.edu.sg/~tanshenm/2171.pdf

And I think we have all seen plants react to directional light and the various spectrums that come with it.

In this sense we can say that the tree is its own observer and that it is not only going to react to and sense its trunk splitting or keeling over, it is also going to sense hitting the ground. So, in this instance we can say that when a tree falls in the forest... it is able to sense the whole affair and there is no need for any other participants in the event to prove, qualify or otherwise confirm that the event has taken place.

[ValenceE]

Dear baywax,

I was referring to ‘sound’ as it is related to the human sense of hearing, so yes, yes, agreed that, if within their ‘reach’, the vibrations made by the falling tree will be perceived by a multitude of entities (including the tree) that have the capability of such ‘perception’, each to their degree, and no human is needed for that to happen.

As for returning to the micro state, well, I consider the recognition of this sound, while telling myself, “hey, there’s a tree falling”, as an end result belonging to the micro/quantum realm.

Regards,

VE

[Descartz2000]

Perhaps the observer needs the tree and the sound to be considered existent. Perhaps the observer is "meaningless" without interaction of some sort.

Please define "meaningless"/:confused:

It is meaningless because there is no point in discussing the event without an interaction between the observer and this event. It becomes null and void without someone present to experience it. When we reflect back on it, we can conclude, 'yes, it did in fact occur. It always was in existence, but it had no value when not observed'. We give it the conceptual qualities (distinction, conceptualization of existing over time, separation from other objects around it, etc).

[DrClapeyron]

The tree falling question is a good example to show humans are extremely conceited. Why would anything's existence be dependent upon our observation?

[DaveC426913]

The tree falling question is a good example to show humans are extremely conceited. Why would anything's existence be dependent upon our observation?

Who said anything about humans - other than you? Now that's kind of conceited. :wink:

[DrClapeyron]

Who said anything about humans - other than you? Now that's kind of conceited. :wink:

I like your humor but silly questions always warrant silly responses.

[DaveC426913]

I like your humor but silly questions always warrant silly responses.
The humour is to be found in the fact that my statement should be so obvious as to go without saying.

What makes you think we're talking about humans? Do squirrels hear the sound? Of course they do. If the tree fell and there were no squirrels, would it make a sound? Same question.

Before humans walked the Earth, sounds still existed.


The philosophical question of whether a tree makes a sound is perfectly valid while having absolutely nothing to do with human conceit.

So - what was your contribution again?

[DrClapeyron]

The humour is to be found in the fact that my statement should be so obvious as to go without saying.

What makes you think we're talking about humans? Do squirrels hear the sound? Of course they do. If the tree fell and there were no squirrels, would it make a sound? Same question.

Before humans walked the Earth, sounds still existed.


The philosophical question of whether a tree makes a sound is perfectly valid while having absolutely nothing to do with human conceit.

So - what was your contribution again?

The question was asked on an internet forum directed at humans. You aren't going to say squirrels check up on their emails daily and then visit physicsforum?

[DaveC426913]

The question was asked on an internet forum directed at humans. You aren't going to say squirrels check up on their emails daily and then visit physicsforum?
What does that have to do with anything?

[DrClapeyron]

What does that have to do with anything?

The tree was certainly around when it fell, why wouldn't the tree count as an observer?

[DaveC426913]

The tree was certainly around when it fell, why wouldn't the tree count as an observer?
You did not answer my question. Why do you think this question presumes the conceit of humans?

I contend that the question is perfectly valid without any reference to humans' participation, so why are you presuming anyone thinks humans must be involved, and thus assuming our conceit?

Please explain.

[DrClapeyron]

You did not answer my question. Why do you think this question presumes the conceit of humans?

I contend that the question is perfectly valid without any reference to humans' participation, so why are you presuming anyone thinks humans must be involved, and thus assuming our conceit?

Please explain.

So does one refer to something other than a human? Let's look at the setting: the woods. Woods implies something away from human construction, society and presence. We are lead to believe that there is no one in the woods. Apparently the animals and plants and the tree itself never count as one or an observer.

[kote]

So does one refer to something other than a human? Let's look at the setting: the woods. Woods implies something away from human construction, society and presence. We are lead to believe that there is no one in the woods. Apparently the animals and plants and the tree itself never count as one or an observer.

We use humans and sounds as an example because we are familiar with being human and perceiving sounds. We could just as easily have asked if the sensation of the echolocation of a bear entering a cave is present when there are no bats around to sense the bear entering.

But that would make for a pretty awful example wouldn't it? We have no idea what the sensation of echolocation is like. I'm pretty sure none of us know what it's like to be a bat.

Do bats perceive the sensation of sound in the same way we do? If not, we have to stick for humans for this example.

I suggest reading the posts earlier in this thread explaining the question with qualia. You can also look up qualia on the net. "What is it Like to be a Bat?" is a famous philosophy paper by Thomas Nagel that talks about this question. See http://en.wikipedia.org/wiki/Qualia.

[DaveC426913]

So does one refer to something other than a human? Let's look at the setting: the woods. Woods implies something away from human construction, society and presence. We are lead to believe that there is no one in the woods. Apparently the animals and plants and the tree itself never count as one or an observer.Yes. That is a perfectly valid line of argument.

Rather than following the line of argument, you instead chose to simply damn all of human society with the judgement that they are conceited. This is a discussion-closer. (Note additionally, that you seem to be the only one who holds this judgement. No one else seems to struggle with the idea that the question is not human-centric.)

So, I'll rephrase your comment as a discussion-continuer:

Q: What about non-human observers? There are surely animals in the forest. (I thought maybe trees could count, but then I realize how silly that is, since trees don't have any hearing mechanisms.) If there are animals in the forest, does the tree make a sound?
A: Yes. Animals will hear the sound. The question is not human-centric. Consider the question to be: if a tree falls in the forest and no creatures are around, does it make a sound?

Now the question is getting to the nitty-gritty. What is "sound"?

[DaveC426913]

We have no idea what the sensation of echolocation is like. I'm pretty sure none of us know what it's like to be a bat.
I've got some ideas for a demo of that. All I need is some funding...

[disregardthat]

That it is a tree, or what sound is is irrelevant. The riddle is supposed to make us focus on the link between the concepts of perception and existence.

Does it make sense to consider the existence of an object independent of perception? I say no; the object is a purely a product of our sensory apparatus. It is a construction of the mind - an interpretation of a formless "external world". Forms (properties like shape, color etc..) are entirely created by the conscious mind.

Some of these forms might be necessary for human experience. Kant argues that for example, all objects must have spatial and temporal qualities; because these concepts are necessary components of all perception.

[DaveC426913]

That it is a tree, or what sound is is irrelevant. The riddle is supposed to make us focus on the link between the concepts of perception and existence.

Does it make sense to consider the existence of an object independent of perception? I say no; the object is a purely a product of our sensory apparatus. It is a construction of the mind - an interpretation of a formless "external world".

The pressure waves exist independent of any person or animal around to perceive them. This does not involve sensory apparati or perception. Is it still "sound"?

[disregardthat]

The pressure waves exist independent of any person or animal around to perceive them.

Pressure waves are concepts created by the mind as any other concept. Pressure waves are also a construction of the mind. They do not exist independently of the perceiver.

[DaveC426913]

Pressure waves are concepts created by the mind as any other concept. Pressure waves are also a construction of the mind. They do not exist independently of the perceiver.

This is completely false. Why would you say such a thing?

Are you saying that when the tree hits the ground, the air around the tree is not moved? Does it not propogate these movements in a spherical front radiating out from the tree at the speed of sound?

[disregardthat]

This is completely false. Why would you say such a thing?

Are you saying that when the tree hits the ground, the air around the tree is not moved? Does it not propogate these movements in a spherical front radiating out from the tree at the speed of sound?

I am not at all saying that. If I did I would accept the notion of a mind-independent structured world.

[russ_watters]

This one isn't philosophy either. Dave is right, the riddle is a silly one that reduces to an argument over the definition of "sound". If a "sound" is a pressure wave, then yes, it exists whether anyone/thing hears it or not. If "sound" is what is detected by our ears, then it doesn't. The line of discussion about whether anything exists independent of the mind is just overzealous Matrix fandom.

Thread locked.