Order of Kilopi
i came across this page accidentally while clicking around the Bitter Films website. they have a page wtih hundreds of random links on it, and this was one of them.
http://www.bitterfilms.com/notlooking.html
it is a really neat way of looking at things, but how accepted is it as a theory?
Order of Kilopi
It'd better exist when I can't see it, or I would have had a heck of a time being born.
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"If a tree falls in the woods, and no ones around to heear it, does it make a sound?"
Order of Kilopi
"are you kidding" Roy here fell down three weeks ago, and hasn't shut up since"
gotta love Family Guy..
but how about my question? this seems sort of like a religious deal, but i've also read before that the mere act of observing something affects it- even from great distances.
i was going to ask this in AGM, but i want to know the scientific merits of it. it seems at least mildly plausible, i guess..
Order of Kilopi
I highly highly doubt it.Originally Posted by novaderrik
There's many ramifications on the idea that observing an object changes it, much less creates it. If we "create" matter by merely observing it, then how did matter on this Earth exist before there were any people, and then any animals at all? It goes against all common (and uncommon) sense, and furthermore makes NO sense whatsoever. It's a ridiculous concept at best.
I also am very skeptical on the idea that only observing an object changes it. From what I know, that supposed "theory" came from Quantum Mechanics dealing with Quantum Concepts; particles, not macro-scale objects.
I'm not fully knowledgable on the subject, but there's no way that you can convince me that my house doesn't exist when I close my eyes.
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We can be resonably confident it existed a hell of a long time before there were eyes of any form to observe it; it is a good bet it will exist a hell of a long time after human and all other eyes no longer observe it. However, our stardust will still be roaming to cosmos.
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The article contradicts itself. It first says In this case the mica, not a conscious being, is the object that transforms what might happen into what does happen.. Then it says But in the quantum world, things are not so straightforward. The particle and the cat now form a quantum system consisting of all possible outcomes of the experiment. Surely if mica is a valid obsever able to collapse the quamtum state function into a particular outcome then so is a cat, whether a human is aware of the cat's state or not. In my humble opinion this whole idea of human observers being necessary to make the universe real is totally unscientific and utter nonsense.
Order of Kilopi
In my not-so-humble opinion, I completely and wholeheartedly agree with this statement.
Order of Kilopi
And the universe continues to exist even if you write bad philosophy books proving its non-existence!
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Depends on how you define exist, I suppose. With my definition, the answer is "yes"...
Order of Kilopi
Love it.And the universe continues to exist even if you write bad philosophy books proving its non-existence!
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Actually, it is more specific than that. The Universe doesn't exist because of human observation, but because of MY observation. Just be careful or I'll stop observing you.
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Depends on what you mean by "observe." If you mean "look at it with an eye," then yes, everything still exists when not observed. If you mean "completely remove from the universe so that it has no effect on anything at all, and is therefore not even indirectly observable by any mechanism," then the statement is vacuously true.
I think the problem with the quantum analogy is that it forgets that no matter how isolated your unobserved particle is, it's still having an effect on the things around it. You don't need to measure the particle's state directly to get a good idea of what it is. You can just measure everything else and make a good guess. And of course, when you do go off measuring something, you change its state. You can see the results of that state change with the delayed choice experiment mentioned in the article.
The delayed choice experiment looks funny to me, though. In QED, Feynman says that if you send photons one at a time through the slits, you don't get the wave pattern. It's the interaction between photons that causes the funny pattern, and there's not really a paradox about waves and particles. Photons are just particles, but they behave like waves when there are lots of them, in the same way that water molecules are not waves, but if you put a bunch together you can go surfing.
I can see what Wheeler's saying about the future choice being intimately related to the history of the object, though. Most of physics is supposed to be time-reversible (increasing entropy is an exception). Perhaps a better interpretation is that you can only see the particles that took a certain path, rather than claiming that because you observed that particle, it took that path. The result is the same, but causality isn't violated, although I don't know if that's really a problem, except maybe from a thermodynamics/entropy standpoint (although entropy considerations can be violated locally, so long as it all eventually averages out, so maybe not).
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That's not how I remember it. IIRC you still get the wave distribution even if you fire only one photon at a time at the double slit. It's as if each photon becomes a wave, travels through both slits simultaneously, interferes with itself, and turns back into a particle just before it hits the screen (so long as you're not peeking to see which slit it goes through).
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Oops! I just looked it up, and he explicitly says that even one photon at a time gives an interference pattern. It ends up being because of self-interference. (Note to self: learn to do the math for this -- it looks cool) BUT each particle goes through only one slit: it does not truly act as a wave. It interferes with itself like a wave might, but there's still only one observable particle, with a (somewhat) definite position at all times.
But he also justifies what I said about Wheeler's experiment, where the act of observing the particles as they pass by changes them, which is why you see the discrepancy Wheeler describes.
Order of Kilopi
I noticed this contradiction as well. Yet there is a lot that Wheeler is saying that is not being fully appreciated in this thread. First of all, we must distringuish three cases of the importance of observation, ordered toward weaker strength:
1) if you stop observing something, it ceases to exist
2) to exist, something must be observed at least once, by a conscious being
3) to exist, something must interact in an irreversible way with something macroscopic, destroying the quantum phase correlations
Note that Wheeler is clearly talking about (3), not (1) or (2), despite the focus of much of this thread. That's why I don't understand why he mentioned the cat paradox, since the cat paradox is no paradox at all-- in the usual story, the cat interacts in irreversible ways with macroscopic entities and would clearly have to be described as what is called a mixed state, not a superposition state. A mixed state is like when you roll a die but haven't looked at it yet.
If we write off the cat paradox reference as an illustrative device that we were not intended to take literally, then Wheeler's version is actually a rather weak interpretation of the importance of measurement, and it's a pretty inescapable part of quantum mechanics. It is clear from delayed choice experiments that measurements really do collapse wave functions, what Wheeler is saying is that out in the universe there must be lots and lots of uncollapsed wave functions, even though we have the illusion when we look at the universe that they are all collapsed by now. Given how quantum mechanics works, there is some aspect of what he is saying that is inescapable. The questions are, what does it take to destroy quantum coherences (i.e., collapse a wave function), and how much of the universe (say, the cosmic microwave background) is yet uncollapsed?
If one wants to go farther and talk about consciousness, a la Wigner and Linde (who was quoted in the article), that's where things get a lot dicier and become nonscientific because they are unanswerable (given that we cannot escape our own consciousness and survive, as far as we know anyway). But note that Wheeler didn't play that card, and is on a pretty solid quantum footing although he has not answered the two questions I mentioned above.
(Edited to correct Wheeler's name)
Last edited by Ken G; 2006-Jan-03 at 05:12 PM.
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Let's see what Quantum Mechanics really says...
You are probably familiar with the Heisenberg Uncertainty Principle (HUP). This limits our knowledge about the observables of a particle. The question is: do these observables have simultaneous reality? Generally, the answer (per QM) is: NO, they do not.
This does not mean the particle itself is not real. QM does NOT say: "particles are not real until observed". It simply says that the values of observables are not real until observed. (This is clearly a lot different.)
Order of Kilopi
This point is well taken, that even when a wave function is "collapsed", it is not more real, it is just a tradeoff in uncertainties. Yet when we say that we observe a photon coming from a certain direction, we tend to count that as part of reality, and that part indeed did not exist before we observed it. It think that's all Wheeler is saying, that the concept of "existence" is intimately related to the concept of doing measurements and collapsing wave functions. The particles are certainly real, but the "reality" Wheeler refers to includes not just the particles but also where they were born, what path they took, and where they "died". I think the points are overstated in the article, in the usual way when scientific concepts are translated for sensational appeal, and I agree with DrChinese that the uncertainty principle is the fundamental idea. Perhaps the concept of "existence" needs to be better clarified in scientifically specific language, to test what new concepts Wheeler is really bringing out. Note we are not talking about the philosophical issue of when a tree falls in the woods, we are talking about the state of things, and under what circumstances quantum coherences survive. The ambiguity of the wave function, complete with its coherence information, represents a different type of "existence" than we normally mean, so it is actually a kind of conversion from one type of existence to another that Wheeler is talking about, but oversimplifying for mass appeal.
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If I put someone in my Ignore list, does that person still exist?Actually, it is more specific than that. The Universe doesn't exist because of human observation, but because of MY observation. Just be careful or I'll stop observing you.
Order of Kilopi
Sure, just not to you.
Honored Member
I just stopped observing Swift...Actually, it is more specific than that. The Universe doesn't exist because of human observation, but because of MY observation. Just be careful or I'll stop observing you.
Hey, where'd he go?
Ah, my condolences.
Once thing for sure, the Universe was here long before humans and their philosophies, and it will be here long after humans and their philosophies are gone.
The Universe (AKA, reality) could care less.
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No, the universe couldn't care less!
Honored Member
Bottom line:
The Universe does not care.
(note the clever non-use of an apostrophe)
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It's a question that's designed to be weaseled out of. If you're not allowed to look at it, you can't inductively say anything about it.does the universe exist if we're not looking?
But we can and do look at the universe all the time. Furthermore, we can look at the universe at one time, and then again at a different time, and arrive at the conclusion that it has behaved, in our absence, exactly as we would expect it to behave in our presence. Leave a piece of cheese on a table, come back in a week, and you will find it rotten, exactly as if you were staring at it the entire time. You may cry foul because we looked at the cheese again, but if we never observe it and are never effected by it again, the theory that reality is dependent on observation becomes meaningless and unimportant. "Now pay no attention to the universe behind the curtain and listen to what I say about it!"
All our experience points to a universe that exists independently of whether we are constantly watching it or not. Philosophically, primacy of conciousness, especially human conciousness, regularly gets the stuffing knocked out of it by science. In light of our experience with the constancy of the universe and physical law, primacy of reality makes more sense. Generalization leads us to conclude that the cheese would be rotten anyway, because cheese left alone for weeks is always rotten in our experience.
BTW, if you want to drag quantumn physics into this, QP "observations" aren't concious observations made by aware observers, they're particle collisions, so QP isn't dependent on human awareness. This misinterpretation of QP is a favorite of solipsist philosophers.
Order of Kilopi
But Wheeler is not talking about philosophy, not at all. He is talking about physics, and yes, quantum physics. The problem is that he uses the word "existence" without a clear scientific definition. Perhaps he has supplied one and the article just missed it, but it's a rather crucial point. We really cannot comment on the validity of the point Wheeler is trying to make until we know how he is defining existence. It looks to me that he is defining it as a collapsed wave function, i.e., a wave function with a definite value for some commuting set of observables. If that is what he means, then we already know he is right, quantum mechanics makes this quite clear. The issue is really, why is this the natural definition of existence? Personally, I don't care much about the definition of existence, but I'm still curious about the simple question of how much of our universe is comprised of collapsed (i.e., macroscopically coupled) wave functions, and how much of our universe continues to exist in superposition states of many possible measurements?
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Still, here is the misunderstanding. It seems like anthropocentrism struggling back into our theories.According to the rules of quantum mechanics, our observations influence the universe at the most fundamental levels. The boundary between an objective "world out there" and our own subjective consciousness that seemed so clearly defined in physics before the eerie discoveries of the 20th century blurs in quantum mechanics.
Under the seeing double experiment, the article has our scientists "deciding" which path a photon takes over interstellar distances by which direction they point their telescope. In fact, wouldn't it be the first gas molecule or field with which the photon interacts that determines it's path? And why isn't reflecting off a mirror an event that could collapse the wave?
BTW, this particle/wave duality thing annoys me. It seems like they switch from one to the other as the situation warrants. Is there one continuous model for the way particles behave, rather than constantly switching between them based on bizzare QP rules?
Order of Kilopi
Hum,
Light isn't sometimes a tiny billiard ball particle or a ocean wavelike wave.
The descriptions are just tool to understand how they work.
We don't have anything in the real world that acts both together at the same time.
A tip maybe to write particle/wave duality backwards avoiding the confusion that the associations may lead to.
elcitrap/evaw duality is easier to understand now huh?
BTW, There is no tree, and no sound.
Everything is an illusion.
Order of Kilopi
If you say so...
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I know! I know! Pick me!
First define sound then I'll tell you.
Is sound merely the vibration produced by the tree falling? If so, then yes.
Are these vibrations called 'sound' only when they reach an ear and they become translated into neurological signals that a living brain can interpret? If so, then no.
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