I believe I can prove that no image is a physical object. To do so, I will prove that there exists no image that is distinguishable from the object on which it is projected.
I’m going to begin with the premise that the surface of an object is a physical object. My second premise is going to be that a physical object may be described by its atomic composition. My third premise is that an exhaustive description of the atomic composition of any physical object will distinguish it from all other physical objects. My final premise is that the wall is a physical object.
Next, I’m going to select an arbitrary wall, say, a brick wall. Then, I’m going to select an arbitrary image to project onto the wall, say, an image of the wall. For every atomic element that describes the surface of the wall, the identical atomic element is also a description of the image. If a particular atom in the surface of the wall is red, then a corresponding atom in the image is red. If a photon is emitted from the surface of the wall, then a corresponding photon is emitted from the image. In general, the surface of the wall and the image are indistinguishable. Since both the object and the image selected were arbitrary, then by the Rule of Generalization, the previous inferences hold for all objects and images.
Therefore, there exists no image that is distinguishable from the object onto which it is projected.
I’m not sure I understand the question, then. If there are physical objects, an I assume we agree that this is so, then if the spatial arrangement of their atoms is different at another time, and that second arrangement of atoms is a physical object also, then what is unphysical about the transition?
OK, taking it down to basics, a toddler who has never seen a watering can before is shown one, and the precise neural activity logged. They then, somehow, trigger that precise activity. The toddler “remembers the watering can”, yes? They know that the toddler is remembering a watering can, yes? The memory they formed from the bionic implant above the toddlers eyes is the visual memory the toddler had, yes?
Now, the next day, the same watering can is shown in the same conditions. It triggers similar neural activity, but not identical. That is different from our silicon computer, which would remember it exactly the same as the first day. All “they” would be left with is some statistical correlations: they’re pretty sure their bionic memory is still similar to the “avergae” of those two neural activity configurations, but it has become “a little bit encrypted” by the biological brain’s plasticity and inputs from other senses in a changing environment.
So, yes, you’re quite right that it’s not just the environment which “encrypts” human memories but also the very brain itself (one could imagine a silicon computer performing a one-time hash every day, and throwing away the key). However, I hope that you’d accept that this difficulty in accessing human memory compared to silicon is not somehow metaphysical. Silicon computers have non-computable problems, too: I’d suggest that this did not change their nature.
Physical processes and computational processes, or computational processes and human cognition.
The image and the object are *spatially separated, such that their 3D coordinates to say, me, are different? If so, I can still distinguish them, surely?
No, honestly you can’t. Another way to think of the problem aside from pure analytical proof is that whatever portion of the wall, paper, or what-have-you it is that constitutes the image, it is still a portion of the wall, paper, or what-have-you. The image is just a part of the wall. Images (as in pictures) are something that you learn to become familiar with. Over time, your brain learns to present to your consciousness an awareness that an image is supposed to represent something. But that’s completely arbitrary. Projecting an image onto a wall is no different from shining a light on it. All you have is a lighted wall. You’ve merely excited its atoms.
Okay, now I’m totally confused. What exactly are we debating here?
I sincerely hope nobody is saying that an apple and the image of an apple are the same thing, or indistinguishable from another. (For one, I can’t make cider out of a photograph, nor should I try to slice it into pieces and eat it.)
By extension, an apple and the memory of an apple are not equivalent, and should be distinguishable. Heck, my memory of an apple probably isn’t the same as anybody else’s memory of an apple. However, as long as we’re talking about apples, we can agree on some general attributes that make up “apple-ness”.
My memories are physical, and “real” in the sense that if you look into my head while I’m remembering something, you’ll see neurons light up. (However, I don’t think anybody can make an exhaustive list corresponding neuron patterns to specific memories, because our brains vary from person to person, and also from moment to moment within the same person.)
But - and here’s the point of the debate, I think - just because I remember something, does it necessarily follow that it must exist, physically? I’d say no. (But I say that because my brain is capable of coming up with some really weird stuff, as my [url=]http://www.livejournal.com/tools/memories.bml?user=dotchan&keyword=Weird+Ass+Dreams&filter=alljournal of dreams can attest. I also have a small army of characters that only exist in my head, although now that I’ve started writing their stories down, they “live” in the minds of my readers, too. I consider them to be real - not in the same sense that I am, of course, but real nonetheless.)
The whole mess does get very circular and self-referencial - such is the nature of life, methinks. And I don’t think it’s within the realm of science or logic to find the starting point. (Isn’t there like a Theorem of Incompletness that says something about unprovable axioms…?)
You’ll be relieved to know that no one is. We are saying that the image of an apple projected onto a wall is indistinguishable from the wall. It is photons from the wall that are striking your retina.
Maybe you could be more specific. I assume you mean how software gets modified, right? It gets converted/modified/written in so many ways that no one link will do. My response all involved things I have been directly involved with in the past 30 years. If you narrow it down, I should be able to find a link, but compilers and emulators are so far apart that not even a textbook would cover both.
To summarize all this, an image projected onto a wall is just a lit up wall. It’s still a wall. A photograph on a piece of paper is just an emulsified piece of paper. It’s still a piece of paper. A picture printed by an inkjet printer is just a coating of ink. It’s still ink. It takes familiarity with other things to perceive them as images.
That’s okay. Believe me, I completely understand. I once told a man that existence is not a predicate. He asked me, “What does that mean?”. Indeed, can one count the textbooks?
But you can distinguish the frequency distribution of the photons of the image being projected onto tthe wall, and being reabsorbed and then going to your eye, and the photons from white light that get bounced back changed by the color of the wall. If you want to confuse things more, think of an image of the wall projected onto the wall.
I’d say that the image is physical, assuming you think photons are, since you can measure and collect the photons from the wall.
Processes are more interesting. Do you consider verbs physical, assuming nouns are? Define a process as the change of state of a physical thing. Is running physical by your definition? It is not a physical object, true, but if it is not physical then we are talking at cross purposes.
Once we get there, we can discuss abstracts. If an abstract is only existent as a pattern of memories, neurons, what have you in our brains, then it is perhaps physical. If it has a Platonic existence outside anyone or anything’s brain, then I can agree that it is not physical. If the abstract exists in the mind of God, then we have a problem .
But let’s begin with the physicality of verbs, okay?
I think our problem is different levels of hierarchy. Is a red wall the same a blue wall? Yes, they are identically wall-like, but they are different if your interest in the wall runs to color. A red wall with an image projected is the same as a red wall without, if wall color is your concern - but if you are worried about suitability as a screen for a presentation, then they are different. Dive even deeper, and we might care to distinguish walls based on their reflectivity, smoothness, etc.
People trying to do AI for language or story understanding ran smack into this problem, since the meaning of wall, and how much information you need to carry with the tag “wall” depends on the context. “Wall” in “The walls have ears” is very different from “this wall is a good place to project our slides” or “this is a good wall to climb.”
Um… actually, that’s exactly what I did. And rather than confuse things, it proved that the image is not physical. Here’s that post again, for your convenience:
I believe I can prove that no image is a physical object. To do so, I will prove that there exists no image that is distinguishable from the object on which it is projected.
I’m going to begin with the premise that the surface of an object is a physical object. My second premise is going to be that a physical object may be described by its atomic composition. My third premise is that an exhaustive description of the atomic composition of any physical object will distinguish it from all other physical objects. My final premise is that the wall is a physical object.
Next, I’m going to select an arbitrary wall, say, a brick wall. Then, I’m going to select an arbitrary image to project onto the wall, say, an image of the wall. For every atomic element that describes the surface of the wall, the identical atomic element is also a description of the image. If a particular atom in the surface of the wall is red, then a corresponding atom in the image is red. If a photon is emitted from the surface of the wall, then a corresponding photon is emitted from the image. In general, the surface of the wall and the image are indistinguishable. Since both the object and the image selected were arbitrary, then by the Rule of Generalization, the previous inferences hold for all objects and images.
Therefore, there exists no image that is distinguishable from the object onto which it is projected.
For two things to be different, it seems to me that they have to be distinguishable from one another. The portion of the wall surface on which the image is cast is identical in every respect to the image, down to the coordinates of each atom (not as in H2, but as in smallest part). If an atom in the image is at coordinate (x, y, z, t) and the same atom on the wall is at (x’, y’, z’, t’) then x = x’ and y = y’ and z = z’ and t = t’. They are one and the same. It is not an image physically separate from the wall, but just a wall with some color.
I don’t like the word “levels” because I believe that it does confuse things. It’s really just associations — reconciliation of new things with things that are already familiar.
Ok. I didn’t get you were talking about the same wall with or without an image. :smack: Also, I agree that an image is not a physcal object. - but it is physical. An object must have mass, while an image is defined as a set of massless photons. Now, if you wish to say that in your definition photons are not physical, then I agree.
The reason I have not been participating in this thread except to stick my nose in about computer and hardware issues is that I think the whole thing is a matter of definition. So I still think everyone is right.
My spidey sense is tingling: I’m sure I glimpsed that same pokey stick over my left shoulder just then. I will have to trust you when you said you’re not seeking to use it again.
We have agreed that there are physical objects (I’m taking this to be so, since you read the OP, have had clear opportunities to say ‘Halt!’, and made statements yourself like “I agree that such and such is associated with the physical” and referenced “physical locations in the brain”).
You are now, instead, asking questions akin to What are the physical properties of “object”? I can only interpret this as you forgoing the baby steps we’re making and bounding way off down the path again to explore the physical nature of our thoughts when we use words like “object”. This is not yet what I’m talking about. Eventually I will, by appealing to a kind of ‘average’ of all the memories of things we call “objects”, but let us put this aside for a moment.
The tree is a physical object. You cannot disagree with this without essentially returning to the prior thread and contradicting all kinds of things you’ve already said in this one. Like I said in the OP and at least seven times throughout, I have no more interest in debating the premise “There are physical objects” than debating solipsism.
The tree doesn’t need anyone around. Trees were there before minds, human memories of trees, and the linguistic referent “tree” associated with those memories. It is certain atoms having a spatial relationship to each other and to other atoms (the ground, say). That same 3-D relationship holds at different timeswithout anyone around also.
Now, the tree fallingdoesn’t need anyone around either. Agreed? The spatial relationship between the tree and the ground is different at different times, having certain consequences, notably the propagation of a longitudinal pressure wave (itself a spatio-temporal relationship between air molecules). The tree makes a sound without anyone around.
Do we agree that the tree falling, when nobody is around, is as physical as the tree itself? Again, I hold out my hands ready to catch you if you trip making this step.
Ah, I didn’t read the original post correctly. Having read it again, you’ve correctly identified sloppy taxonomy on my part calling an image an “object” as such:
Atoms not only have spatio-temporal locations, they have energy states. The difference between a wall with an image projected onto it and a wall without is the energy states of those atoms, which is just as physical a property as spatio-temporal location. Those same atoms in a different spatio-temporal relationship are “rubble”. In another, they are the wall “falling down” (and, like I am trying to convince other-wise, “falling” is as physical a process as the wall is an object).
Is a “fall” an object? No, you’ve got me - I was careless in my wording. I should have used “entity”. An “object” is a 3-D arrangement of atoms (even if it’s only one atom thick), which doesn’t need an additional time co-ordinate, like an ice cube: Oxygen atoms at [x, y, z], Hydrogen atoms at, say, [x±a, y±a, z±a]. For “object”, we assume that [x,y,z,t1] is identical to [x,y,z,t2].
But what if [x,y,z,t1] is not identical to [x,y,z,t2]? We say a change has occurred: the ice cube “becomes” a puddle. There has been a “melting”. Again, a melting isn’t an object since it requires that t coordinate also.
And an image? We need the energy states of each atom in our square brackets also, in order to distinguish the atomic composition we call “wall with image” from that of “wall without image”.
You’re quite right, Lib: I can’t call an image a physical object without stretching the word past the breaking point I myself have set out. Perhaps even “thing” is a stretch, although I don’t think too many here would complain if I called a “fall” or a “melt” a thing. And an image or a memory, I’d say, are less contentious still with “thing”, but still fall outside “object”.
Objects, falls, and images are all physical entities. Thanks for helping me put that right.
Just to clear up one thing, Sentient, I said (admittedly later) that by “atom”, I meant as in smallest part, not as in hydrogen. It was an analytical reference in an analytical proof. If we consider the modality of the atoms, then the accessibility relation is unique (not in the sense of like nothing else, but in the sense of both serial and convergent): (wRv&wRu) -> v=u. This is derived from (Eu, wRu) anded with (wRv&wRx -> u(vRu&xRu), if you care to check my accuracy. And it means that any arbitrary X from the wall is identical to the same X from the image.
Still, you can use a chemical atom if you like. Point to any one on the wall’s surface, and it is a component of both the surface and the image, and is identically coordinated. In fact, wherever an electron’s orbit collapses, you can interchangeably say that a photon was emitted from either the wall or the image. They are one and the same. I’m about to respond to Voyager, and I think it might have a bearing as well on “object” versus “thing” or whatnot, so feel free to check that out as well, and rebut or agree as you see fit.
But the massless photons eminate from the wall. There has to be an electron whose orbit collapses. And the electron has to be a part of an atom (in the physics sense). The image is merely a part of the wall that is emitting photons that correspond to points in the image. The whole wall is emitting photons.
All that is to say that the image is merely a perception of the wall.
If you put a blind man in front of the wall, he will perceive no image. He might perceive a bit of heat as the light heats the wall, but that’s it. You could give him the same effect by using a torch on the opposite side. It is the wall that is physical; the image is just a perception.
Now, here’s where the definition part comes in. The physicalist will declare that perception is physical too. But that’s only because he has taken as axiomatic that anything you name is physical. It is a system built on a conclusion as a premise. Now, I believe that God exists, but I am scrupulously avoiding any and all metaphysical references as we examine this issue of physicality. If we’ve already postulated that all things are physical, then what are we doing here? We need only a simple syllogism: all things are physical; an image is a thing; therefore, an image is physical. Done. End of story. There is an OP, and possibly one or two replies of “Yep,” “Uh huh”, and “You’re so right.”
But if we are going to show whether an image is physical, then we do not start with the premise that it is. It seems to me that to be physical, something ought to be made of physical stuff — elementary particles, strings, or whatever. Or, in terms of spatial-temporal, it ought to be distinguishable from all other spaces and times. The physicalist will argue that perception emerges from the physical and is therefore physical. But there again, there is the presumption that physical is everything conceivable plus everything that isn’t.
To test the tautology of physicalism, propose this question: If the metaphysical God exists, is He physical? If the physicalist answers yes, then he has defined physical as everything that is proposed, even contradictions. If he answers no, then he has admitted that physicalism is false. I have often scolded materialism as the most logically difficut position to hold, but its spawn, physicalism is more difficult yet. The physicalist must posit either one of two things: (1) contradictions exist, or (2) I’m wrong.
Sentient and I are mutual admirers, and I believe that he is a brilliant and insightful man. In fact, he is not above reading this post and rejecting physicalism on account of finding my argument compelling. Like any man, he will scrutinize the post for possible error because of the strong emotional attachment that men develop with their worldviews over time. But he has the intellectual courage to put his emotions aside and evaluate this thing with impeccable honesty. And he will not nitpick. He will not hang his hat on some obscure interpretation of the obvious.
I know what it’s like to change a worldview. I was a materialist. But upon discovery that I was standing in quicksand, I simply stepped out — despite years of emotional baggage and attachment to the theory. He is a man who will not hesitate to do the same. You just watch.
If you wish. But so is the wall. Photons are coming from all over it. You’re merely selecting those photons to which your brain has assigned a perception born of familiarity with other things. You’re simply going, “Hmmm… that portion of the wall that depicts a battle from World War II is familiar to me, not as a wall, but as a battle from World War II.”
