If so, what physical parameters define them?
i voted no, but i believe that they may need a physical body in order to exist
Ok, I voted no. My first thought was, if we are talking about a physical universe, what purpose would there be for a none physical entity to force the wave collapse? But then I remembered what I have been reading by Ken Wilber, Valorie Hunt, Deepak Chropra, and realized I had not converted what I was learning to my own reality. Hmm, Is this a step toward defining the observer, by agreeing that he is not physical?
I think that the observer this information concept but not physical.
Voted yes. The question didn't single out conscious observers, so I'm counting any particle or system that changes upon interaction with another particle or system as an observer (i.e. somehow records the observation via a change of state).
If we wanted to get more picky, a more common definition of the word 'observer' is simply a system like the one above with the capacity to not only observe but to be consciously or subconsciously aware of it. While the mechanisms of consciousness are not fully understood, those aspects of it that are or that have well-founded theoretical explanations are entirely physical AFAIK. We understand it more and more as further study progresses, so there is no reason I see to believe that when a full understanding of consciousness is arrived at, that understanding will be of a fully physically-explained consciousness.
I cannot, then, answer the second question beyond 'at a fundemental level, the limitations of the laws of physics' - taking the view that all fundemental laws of nature are laws of physics and all other laws of nature are emergent from more fundemental laws of physics.
I've voted yes, mainly because whenever we solve any problem, we assume that the observer is present. Also if the observer is not physical, how can it 'observe'; if it is not physical, then why talk about it in physics.
is the universe essentially physical?
you are essentially assuming that "what is", the Reality, is fundamentally physical. i say this, because you must be referring to the "problem" of QM, where the act of observing affects the outcome of "physical" events. therefore, i say, you are in assumption that the universe is basically "physical", and that an observer must, in fact, be "physical". for if the observer is non-physical, then Reality, too, it follows, is non-physical. see?
Yes, that's basically my view too. If an entity suspected of being non-physical were to interact with a physical entity in the same way that another physical entity does, what is it that makes it non-physical? So if there is a non-physical reality out there, it seems logical we would never be aware of it in the way we are aware of consciousness or information, and so have no reason to think it exists (whether it does or not).
If measurement involves physical interaction with the observer, as QM seems to indicate, why has the magnitude of that action upon the observer never itself been measured?
I'm not sure I understand the question. First off, a physical interaction between the observer and the subject is not AFIAK a QM notion. If you observe the moon, there is a physical interaction twixt you and it mediated by light. This is as true in classical physics as it is in QM.
But I don't understand what you mean about not measuring the magnitude of action upon the observer during observation. Can you provide an example where the change in the observer isn't measurable?
Forgive what may seem like sophism.
If an observer exists it exists in the universe. The universe is physical.
It is the definition of physicality. Therfore an observer is physical.
As Wittgenstein discusses, only the physical can be discussed. The meta-physical cannot. Therefore a discussion of existence outside the logical space of existence is not something that can be defined in order to be considered.
If an obsserver were not physical, the observer would be irrelevent. There is no definition I know of to descibe the existence of a thing outside the system in which all existence takes place.
There is no meta-position possible to make an extra-system description of the universe, therefore it is impossible to describe this system in terms of anything else. An observer which was not physical in this system would probably be defined as physical one or more meta positions (using a meta-language) upward. So within a wider hierarchy of references our "non-physical" observer would still be physical even if we called it not physical.
Everybody loves somebody sometime.
I agree with mmarko. And besides, the whole point of physics is to determine how the universe works, through experimentation etc. You can't experiment with something that is not physical, therefore trying to do so gets you no where really fast.
I voted yes. Since the universe is seen only from my point of view, and since I believe that I cannot interact with non-physical entities, (try and prove me wrong), then non-physical entities do not exist, (try and prove me wrong). So yes from my point of view, (the only one that exists, or at any rate the only one that counts) an observer has to be physical (try proving me wrong). There may be a non-physical observer out there somewhere but it doesn't exist as far as I'm concerned, and never will unless I go completely insane or as the case may be, unless I recover my sanity.
So you are saying that you are 'physical' and you are the 'observer', therefore all observers must be physical. Then you ask others to prove you wrong in this subjective, inductive reasoning. Do you not first need to prove that it is your being 'physical' that qualifies you as an observer.
Let me ask just what physical part of you did the 'observing'? Was it your eyes which recieved photons and converted the signal to electro/chemical info, or was it your brain that recieved the info and interpreted it into a concept? What actually caused the wave/particle collapse:the eye seeing, the brain interpreting, or was it the consciousness of the individual who is aware of what he/she is seeing/interpreting that causes the collapse.
Do we not need to define 'observer' or what function of observing constitutes an observer, in order to determine if physicality is necessary?
No, we all know what physical means, and we all know what an observer is. Since I am the only observer in the universe... oh.. that's it! since I am the only observer in the universe and I am composed of matter, then it is undeniable that all observers are composed of matter and therefore all observers are physical.
But may I ask how you define physical? Are all sub-atomic particals physical. How about the photon which has not mass? Is is physical? Yet it, without mass, acted in a physical world of particles with mass as a messenger of what is 'out there'.
Every particle with mass exists most of the time as a wave. Like a wave in the sea, the wave is only energy but it is the water that has mass. Is the wave 'physical' or is it just the water that is physical?
Surely you see the problem with defining what is physical and limiting interaction with with other particles to that definition. If a mass-less non physical photon can interact with particles we think of as physical, why would the observation of the universe be limited to physical observers or the physical nature of the observer?
Because I'm the ONLY observer in the universe... (I made you all up, I made up this computer screen, I invented the universe and then convinced myself you all are actually out there somewhere, I am god), and I define the word physical. And I define myself to be physical.
I guess my whole point is that you can't prove me wrong, ever, as this question is purely philosophical, and so I am right in saying that all observers are physical, having a pefectly logical line of argument. I never said you were wrong...
Well then Alfred,
While this is the philosophy section of the forum, you seem to be dismissing my argumentation because it is "purely philosophical".
In YOUR universe, are any of my arguments about mass-less entities interacting with particles of mass different then the rest of us? In your universe, do you consider mass-less entities such as energy waves, magnetic fields or the strong force to be physical objects?
I am not dismissing your argument at all. I am dismissing the question posed by this thread xD Have you really found a weakness in my argument? If so please come out with it :P Although I won't deny this thread is stimulating, interesting and amusing all at the same time.
As to your questions about what is physical... if you are a physicist, (I seem to have forgotten how I defined you when I invented you :P) if you were physicist then you wouldn't be asking me that question. At the risk of triggering a torrent of posts I will answer your question. Something made of matter is physical, (you never denied that). A photon interacts with physical objects, and therefore interacts physically, therefore it has physical properties. Indeed it is a physical object...
Ok you seem to want to stick to the framework of physcis in this discussion, well earlier on this thread, the question was resolved satisfactorily in my opinion in that sense.
In conclusion, it nearly always pays to repeat oneself, I'm the ONLY observer in the universe, and I define the word physical. And I define myself to be physical.
still, the ASSUMPTION is that the universe is "physical", because it seems to be. have we considered that, in some way, no matter how far-fetched to common perception, that "physical" reality is some how dependent upon a non-"physical" "entity".
i mean... this really can't be that far-fetched, considering that "my" perception of "physical" reality depends, intrinsically, on my being aware and conscious, to begin with. otherwise, i have no conception of "physicality" at all. so, in at least one sense, "physical" reality is dependent upon some deeper Reality, known to us as "consciousness", which perceives via the sense-organs.
the sense-organs have already, by the time we perceive it at all, done immensely complex re-organization of Reality, in a way that can be comprehended by the mind.
can "awareness" be considered physical? or must awareness be "behind" physicality, in order for "physicality" to be "perceived" at all? is the "observer" the eyeball, or body? or does the observer have eyeballs and a body at its disposal? can a physical "object" be said to have any other physical "object" "at it's disposal", unless there is an awareness and consciousness that is able to use the "disposed" object?
isn't physicality "conscious" or at the very least, "aware" that an observer is present? otherwise, how would there be any affectation? we can say that Earth is "aware" of the Sun, as it is incessantly drawn to it. gravity can be understood as an interaction based on awareness, even though the subsequent action is "only" (which is itself an assumption, when considered philosophically) of one kind.
El Hombre Invisible,
"Upon measuring directly a displacement of Planck length L*, the measurer would receive a momentum reaction equal to h/L*, or 4,000,000 gm-cm/sec, beyond the kick of a mule" (from my website). Any QM action, by and upon the observer but greater than h, seems disallowed under quantum gravity, while classical actions may exceed (and in fact may also be defined by a lower bound of) Planck's constant.
Apologies for not reading this sooner. I misunderstood your point about action (which I intepretted generally).
The point I was trying to make was that to make a measurement you need some kind of measuring device that transmits information from the object to the observer, otherwise you haven't made a measurement.
In most cases of simple direct measurement, this measuring device is the optical and nervous systems of the human observer. The measurement itself isn't one event, but a series of them: several absorptions and re-emissions of photons, currents along nerves, and ultimately a rearrangement of neurons by changing axon connections. At any of these stages, technical feasibility aside, a change of state could be measured and, as such, I would consider them a series of discrete unconciousness 'observations'.
While it is easy to say: "X is measured", we cannot glean any usefulness about such statements in questions such as "Is the observer physical?" unless we say how X is measured. We need to know what is actually being measured and how. In the case of something being displaced by a Planck's length... how would we measure this?
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