Philosophy Discussion Forums

Logicus:

I am so glad you managed to transplant one of your more humorous threads into this one

Thanks Lodge.

Steve3007:

A particle is always a particle. A wave is always a wave. The sun is always the sun. An orange is always an orange. An electron is always an electron. etc.

Logicus:

Maybe, maybe not. Wave/particle duality is what we have been discussing in this thread. Whatever matter is, it sometimes behaves like particles; sometimes like waves.

I don't know how this is relevant to what I said. I didn't mention matter.

Steve3007 wrote:I don't know how this is relevant to what I said. I didn't mention matter.

Waves and particles are descriptions of matter. You stated waves are always waves and particles are always particles. This is not true. Sometimes matter behaves like waves; sometimes it behaves like particles.

But the point I've been trying to make in all my previous posts is that "particle" and "wave" are partial descriptions of observed reality; models of particular sub-sections of it. It's a really simple concept which has nothing, in itself, to do with quantum mechanics. It's simply about classifying groups of observations.

If you are saying that "waves are not always waves", and likewise for particles, you are deviating from the logical rules of language as I understand them. It is literally logically equivalent to the statement: "black is white".

Xris wrote: No need to invent particles when they are not required. Please do not make this leap of faith and somehow believe we have spotted them because we ain't. This god particle if you might have noticed is not a particle but a new aether, a clumpy substance that pervades the universe giving mass to mass less particles. What a load of invented rubbish we are constantly expected to believe in. Polarisation, spin, mass are not consistent with particles but observations we have made. Even when they break the laws of Einstein we ignore the consequences. We simply adjust the mathematics and put it down to the magic of quantum. Science does not need a concept of particles to make technological advances.

There is no known theory that does not require particles as entities within the theory, apart from your theory.

I have no idea what your theory is, apart from the fact that it denies the Standard Model of particle physics. The SM has passed all tests, both experimental and theoretical. In order to discuss your theory, we need to know what it is and thus assess what it explains and predicts. You could be right, and if you are, you will be the most significant mind humanity has ever known. If you are right, we will worship you!

My theory is the Standard Model. What is your theory?

Quotidian:

Isn't the difficulty implied by 'superposition', that the particle doesn't have a location until it is measured? It is not as if it is there, waiting for someone to measure it. Until you measure it, it isn't really there. What is there, is a 'probability wave' - that is, locations within which it has a greater or lesser degree of being found when it is observed. Which is exactly why it isn't really 'a particle' and why it poses such philosophical problems.

I would say that the problem is in talking about what is happening when we are not observing it. As I said in an earlier post, we have observations and we have theories for predicting those observations. When we talk about what happens between the observations, in the context of scientific investigation, it only makes sense to do so if we are talking about inserting a new observation at the desired point.

So when you say things like "Until you measure it, it isn't really there" and "what is there is a probability wave" I think you have to be careful to think what you mean in terms of observed reality. Possibly this is regarded as the Copenhagen Interpretation. But I am wary of labels. They're useful, but we have to make sure we are using them to describe what we believe to be true, not prescribe what we ought to be thinking in order to correctly fit the label.

Xris wrote: No need to invent particles when they are not required. Please do not make this leap of faith and somehow believe we have spotted them because we ain't. This god particle if you might have noticed is not a particle but a new aether, a clumpy substance that pervades the universe giving mass to mass less particles. What a load of invented rubbish we are constantly expected to believe in. Polarisation, spin, mass are not consistent with particles but observations we have made. Even when they break the laws of Einstein we ignore the consequences. We simply adjust the mathematics and put it down to the magic of quantum. Science does not need a concept of particles to make technological advances.

There is no known theory that does not require particles as entities within the theory, apart from your theory.

I have no idea what your theory is, apart from the fact that it denies the Standard Model of particle physics. The SM has passed all tests, both experimental and theoretical. In order to discuss your theory, we need to know what it is and thus assess what it explains and predicts. You could be right, and if you are, you will be the most significant mind humanity has ever known. If you are right, we will worship you!

My theory is the Standard Model. What is your theory?

Steve3007 wrote:But the point I've been trying to make in all my previous posts is that "particle" and "wave" are partial descriptions of observed reality; models of particular sub-sections of it. It's a really simple concept which has nothing, in itself, to do with quantum mechanics. It's simply about classifying groups of observations.

So you are saying that reality is something separate from our analysis of it, and different from the descriptions we have invented for our own convenience. That beyond our current way of looking at things is a greater, and as yet unrealized, view that would encompass both in the context of a more complete understanding.

Logicus:

No, I don't think so. I'm simply talking about observations, finding patterns in them, and categorizing them according to the patterns that they follow. Whether or not this means I am talking about reality, I don't know. Probably not. That doesn't mean reality doesn't exist. I'm just not talking about it.

When discussing scientific experiments - i.e. things that involve making observations - it seems to me sensible to start with that which can be observed. Once we've clearly established our observations and the patterns in them, only then can we go on to think about the sense in which we might want to associate them with something we call reality and the character that reality might have. Maybe we've not yet reached that stage.

But isn't "that which can be observed" already real? Can you decide what is real? Is this a semantic problem?

Semantics certainly do seem to cause problems in this subject because the language, I guess, was designed for it.

But all I'm saying is that we have to deal first with that which can be observed. We don't know if we can decide what is real, of whether the question is helpful, until we've figured out how we're going to interpret the observations. That's how it seems to me.

Steve3007 wrote:Logicus:

... Whether or not this means I am talking about reality, I don't know. Probably not. That doesn't mean reality doesn't exist. I'm just not talking about it.

You definitely are not talking about reality, that is for sure. I have no idea what you are talking about.

When discussing scientific experiments - i.e. things that involve making observations - it seems to me sensible to start with that which can be observed. Once we've clearly established our observations and the patterns in them, only then can we go on to think about the sense in which we might want to associate them with something we call reality and the character that reality might have. Maybe we've not yet reached that stage.

I see, photons and electrons can only ever be observed as particles, but you think I should put my finger in a puddle to explain how a particle behaves. You seem to specialise in contradicting yourself.

Teh:

You seem to specialise in contradicting yourself.

The wisdom of Teh:

Post #126:

This is just as well as realism has been experimentally refuted.

Post #142:

I know particles exist, because I am a realist.

Since you have now refuted yourself, will you stop posting mindless assertions of absolute truth and disappear in a puff of logic?

---

Another thing that intrigues me: What is your purpose in posting messages on a forum like this? I imagine you might want to communicate, and perhaps even share, ideas with people? If so, do you think your streams of shallow ridicule help you to further this goal?

Teh wrote: You definitely are not talking about reality, that is for sure. I have no idea what you are talking about.

I'm still waiting for a few good sources to back up your assertions. I'm genuinely interested on why you're so firmly convinced that everyone is wrong, and you have solved all the riddles of QM. It has been a few years since I've actively read up on QM, with a few exceptions of generic articles, perhaps my knowledge is dated.

A quick reference regarding quantum entanglement. You seem to favor Einstein's hidden variable theory as outlined in the EPR paradox, but surely you have read on Bell's inequality, it has been around for a few decades. If I may paraphrase loosely, Einstein thought that quantum entanglement can be explained as follows: if you have a pair of gloves, and you blindly put them in different boxes, after which you separate them, If you open a box and find the left glove, you should not be surprised that the other box contains the right glove.

oh so beautiful. Basically, the process of entanglement sets the pair of particles in a set such as that they will always fit a given set of variables.

Bohr and CO. didn't like the idea because it implied that you would be able to measure a particles momentum and position with an accuracy greater then h. (again loosely) It implied that both particles had the properties before hand, and so you could simply measure the spin on one, and velocity on the other.

On and on they went, until their deaths, arguing much like we are, only much more eloquently and intelligently. Basically it was all a mater of interpretation, there was no real way to dispute it. I would also like to point out that Einstein didn't believe that QM was incorrect, he had too much sense for that. He was implying that it may be incomplete.

Enter Bell's Inequality, I would love to go into details, but honestly I would have to research it all over again, and I recall a headache the first time around. Suffice it to say, that if there is a hidden set of variables, the probability of a given experiment would be considerably higher then what the outcome would be if Bohr was correct. The experiment has been repeated countless times since, and as far as I know, all confirm the fact that there is no hidden set of variables.

Currently this property is being used/tested in experiments such as quantum teleportation and quantum encryption.

Now, if the loose above account is incorrect, I would like you to specifically tell me, in layman's terms, what exactly is incorrect. I never pass an opportunity to correct my misinterpretations.

-- Updated December 1st, 2012, 1:48 am to add the following --

Steve3007 wrote:Ktulu:

I don't remember having heard that pendulum analogy before. I think it is a great way of putting it. But I'm also interested in the way that different people think about things. I'd be interested to know what the more skeptical people think of it. I suspect that some of the kinds of minds that don't like abstract analogies as ways of approaching phenomena that cannot be directly experienced will just suspect it of being more obfuscation and trickery.

If I have plagiarized it, it was done so inadvertently. I have read my fair share of analogies and thought experiments, at this point is hard to say what ideas are original, though I think it is.

-- Updated December 1st, 2012, 2:06 am to add the following --

Quotidian wrote:Isn't the difficulty implied by 'superposition', that the particle doesn't have a location until it is measured? It is not as if it is there, waiting for someone to measure it. Until you measure it, it isn't really there. What is there, is a 'probability wave' - that is, locations within which it has a greater or lesser degree of being found when it is observed. Which is exactly why it isn't really 'a particle' and why it poses such philosophical problems.

I think Steve already attempted to battle this one. Again, I can only offer an analogy, any "macro" analogy is bound to be flawed. You cannot offer an accurate description of something that is not observed. You can make predictions of the next point of observation, and in hindsight attempt to fill the gaps between observation point 1 and point 2. Our experimental data indicates that a single particle, behaves exactly as a wave if it is not affected by another particle. This isn't necessarily just a "theoretical" wave, but a literal one that can actually interfere with itself if split. The reason why hitting it with another particle (collapse) makes it no longer behave as a wave is the real "mystery"/"wonder" of QM.

Once a particle has collapsed, you can now treat it as the tao of Teh. With the exception of quantum eraser, which for the sake of some poster's sanity, I will have the decency of not bringing up. Meaning that a particle, is a particle, is a particle, etc. However, prior to the collapse, a wave is a wave is a wave... meaning that it will always show an interference pattern when split, exactly as a real honest to goodness wave would.

I'm not claiming a higher understanding of the process, it makes no sense to me either. I'm just describing my understanding of the experimental results. You're welcome to your own conclusion as long as it takes into account the facts.

-- Updated December 1st, 2012, 2:14 am to add the following --

Logicus wrote:But isn't "that which can be observed" already real? Can you decide what is real? Is this a semantic problem?

I think that especially when referring to QM, "that which can be observed" isn't necessarily reality, but only "that which has been observed". I should clarify that by "observed" I mean interfered with, or affected in some way. I mean "detected" in an active way, not a layman's passive understanding of observation.

Ktulu wrote:You cannot offer an accurate description of something that is not observed.

I don't think that comes to terms with the problem, though. I couldn't describe an elephant in the dark, but it would still be there while I fumbled for the light-switch. The difference with fundamental particles is that they are not simply there, waiting to be observed. The mystery is attendant upon the wave collapse, whereby at the moment of measurement, the particle can be said to be in a precise location, whereas prior to that moment, it wasn't anywhere in particular - as per Logicus # 382. This is the root of the 'measurement problem'.

Steve3007 wrote: The wisdom of Teh:

This is just as well as realism has been experimentally refuted

In single universe interpretations of quantum mechanics, the wavefunction does not refer to "an element of reality".

Since you have now refuted yourself, will you stop posting mindless assertions of absolute truth and disappear in a puff of logic?

A particle is not a wavefunction.

-- Updated December 1st, 2012, 6:24 am to add the following --

Ktulu wrote: I'm still waiting for a few good sources to back up your assertions. I'm genuinely interested on why you're so firmly convinced that everyone is wrong, and you have solved all the riddles of QM. It has been a few years since I've actively read up on QM, with a few exceptions of generic articles, perhaps my knowledge is dated.

There is no better place to start than the video in the Mach-Zehnder Interferometer topic.

A quick reference regarding quantum entanglement. You seem to favor Einstein's hidden variable theory as outlined in the EPR paradox, but surely you have read on Bell's inequality, it has been around for a few decades. If I may paraphrase loosely, Einstein thought that quantum entanglement can be explained as follows: if you have a pair of gloves, and you blindly put them in different boxes, after which you separate them, If you open a box and find the left glove, you should not be surprised that the other box contains the right glove.

I don't favour any particular interpretation. Hidden variable theories have all been experimentally refuted, so I don't spend much time looking into them.

oh so beautiful. Basically, the process of entanglement sets the pair of particles in a set such as that they will always fit a given set of variables.

I would suggest entanglement is more complicated than that. If you have an infinite number of pairs of gloves, box them in the dark, you always end up with left and right matching pairs.

Bohr and CO. didn't like the idea because it implied that you would be able to measure a particles momentum and position with an accuracy greater then h. (again loosely) It implied that both particles had the properties before hand, and so you could simply measure the spin on one, and velocity on the other.

Spin and velocity commute, don't they? Bohr "liked" entanglement as it helped prove him right and Einstein wrong.

On and on they went, until their deaths, arguing much like we are, only much more eloquently and intelligently. Basically it was all a mater of interpretation, there was no real way to dispute it. I would also like to point out that Einstein didn't believe that QM was incorrect, he had too much sense for that. He was implying that it may be incomplete.

Experiments have been done which prove Bohr correct. Many physicists believe that quantum mechanics is a complete theory.

Enter Bell's Inequality, I would love to go into details, but honestly I would have to research it all over again, and I recall a headache the first time around. Suffice it to say, that if there is a hidden set of variables, the probability of a given experiment would be considerably higher then what the outcome would be if Bohr was correct. The experiment has been repeated countless times since, and as far as I know, all confirm the fact that there is no hidden set of variables.

Tests of Bell's inequalities ruled out local realism, and apparently recent experiments by Zeilinger's group has now ruled out non-local realism. Bohr wins!