Free will?

[LegionOnomaMoi]

As much as I've read on the experiments and the books I've read I can't understand the quantum mysticism approach of particle knowing what is going on. I think there is a more logical explanation.

So did Einstein et al., who found this nonlocality so disturbing they dedicated years trying to find a "more logical explanation". All they ended up doing was weaving the ropes to hang themselves.

The way I see the answer to your question is to consider the particle as a wave for a moment. When one wave is going through two slits, then two waves are produced. Same as one wave of water going through two slits rather than one slit. I'm not sure how the particle is doing it I just know it is in fact doing that cause that is what the evidence suggests. Even so the particle is still a single particle that will only land on one place in the screen regardless of the interference that occurs.

I think its extremely important that you make sure to understand what this evidence actually is, including what the interference pattern is.

1) The interference pattern

In a moment, I'm going to say how misleading it can be to use actual water as an illustration, but because quantum systems refuse to be behave properly, I too am going to contradict myself.

I'm sure you are familiar with ripples in a pond or pool. If you drop a rock, or a pebble, (or the the body of your murdered victim who was about to destroy civilization as we know it by telling the world nonsense about quantum processes), into the water, ripples emerge from that location. But maybe you drop two rocks, or maybe there were two scientists who discovered this quantum businesss and you had to murder both, but you don't want to drop them in the same place.

So you drop two objects in two places, and you get two ripples. What happens when the ripples hit?

And that's where I'm going leave water behind (because taking the example further would be, I think, misleading). We're going to move on to real (and by real I mean fake) waves. Specifically, sound.

Most people have had some cool experience with sound and angles. If the re-make of the movie Arthur (not the king) is correct (and movies don't lie) then there is a place in grand central station called "the whisper wall" where you can whisper into one corner of the "room" and someone can hear you perfectly in another corner. In a playground where I grew up, there were tubes in the wood at particular places, and what was really cool was that someone could whisper into one end, and you could hear it at the other end. Same with the simple telephones made from string and cans. And I'm pretty sure that's how modern telephones work- you talk into your end and your voice travels through invisible "strings" that are tied and numbered (where do you think phone numbers come from?) all the way to the person you called, which is why we call it "string theory", because Schrödinger's cat played with lots of strings, creating cellular reception.

Ok, the last part is completely made up, but sound does do some cool things, and like all classical waves, this includes stuff that objects can't. I can bounce sound off of something just like I can a rock. But what I can't do with rocks is this:

This is why classical mechanics is a required course for all rock stars, pop stars, rappers, American Idol-ists, hip hoppers, death metalists, etc. Because when they perform, the places they perform in as well as their instruments can cause problems or be very useful. Specifically sound waves that hit one another can do more than just bounce off of things (the way that rocks, pebbles, dishes, books, and other objects people throw at me do). The picture above (which I'm told is worth a thousand words) is this wonderfull thing that sound can do: if the waves are just right, then they can combine to be a bigger wave (which is why country + rap = crap). Alternatively, if we get just the right pop-star to sing beside just the right death metal "singer", the sound waves can cancel each other out so we don't have to hear either.

Of course, these are the just the two extremes (as well as extremely misleading in the way I describe them), but they are the extremes of interference. Waves need not interfere completely:

But the really important thing here is that this is not something water molecules, rocks, snow balls, etc., can do. Sure, a dish aimed at me may hit the wall and shatter.

And then there's the fact that I am such a great shot I don't even need to dodge bullets Matrix-style: I can hit the oncoming bullet by shooting it. But in either case (dish or two bullets colliding), matter is neither created nor destroyed. All the pieces, fragmented though they be, can still be found.

Interference is something different, because instead of collision and fragments we can get them to "disappear". Or become one single wave. That would be like me taking Matt Damon & Edward Norton and getting an even more talented actor. Or combining the looks and humor of Ryan Reynolds with the talent, all-around nice guy personality, and humor of Ryan Gosling (and, let's be honest, he's pretty darn good-looking too) and getting Perfect Ryan.

And as much as we'd like to do things like that with objects, we can't. But we can with waves. Which brings us (finally) to...

2) Interference patterns

Imagine the above is me firing an acoustic-sonical gun, which shoots focused sound lasers, at the screens depicted above (I made up the name, but the weapon itself is not as science-fictiony as it sounds; see e.g., Sonic Warfare: Sound, Affect, and the Ecology of Fear (Technologies of Lived Abstraction); MIT Press, 2010).

I shoot these sound lasers, aiming for opening O, which splits my laser in twain, and these two sound waves can go through either opening A, or opening B. Once they do, though, I've angled these screens and slits carefully, so that my sound waves "interfere" with one another, creating a new wave (more powerful than before), which hits the last screen in various places.

What would happen if I did this with a potato gun instead? It would go through the first opening, and either hit the next screen, or go through A, or go through B.

However, we know I'm a great shot (I can shoot an oncoming bullet for crying out loud), so the idea that I would miss A or B is laughable. So either my potato bullet will go through A, or will go through B, and either way I can know exactly where it will land ahead of time. If it goes through A, it's traveling at a specific angle that I can calculate ahead of time, perfectly predicting where it will land. Same with B.

IMPORTANT The interference pattern which does or does not show up with the photons is either what happens with the sound gun, or what happens with the potato gun. With the potato gun, there no possibility of interference. If I split it into a million pieces, I can still calculate exactly where each little piece will land. Interference would be me shooting a piece of potato, it going through A, and then suddenly splitting in mid-air and hitting multiple points on the final screen. NOT being split by the slits, which is easily done and easily explained.

The "pattern" we describe as "interference" is what the sound gun can do: split into two waves which then re-combine and interact in mid air, cancelling each other in places or adding to one another.

For particles, like the potato, the sum of what we shoot through slits will be what we get at the end. It doesn't matter if I shoot lots of potato bullets at once, or just one, or if I split one or many, or what I do. If I break up a potato into bullets for my gun, shoot them all through, whatever happens I know that at the end all of my potato will be there (somewhere). Maybe their will be more pieces, maybe two pieces will combine, but the total mass of potato I started with will be what I end with.

 

[LegionOnomaMoi]

Conclusion: Einstein vs. Bohr- No-holds barred life & death (at the same time) match of the millenium
So with the above examples, I'm hoping I can make clear exactly the experiment does (and does not) show.

When sound waves travel down and get broken up into two waves, these waves recombine and either partly or wholly cancel each other out, or they add to one another. Light waves do this too. Young "proved" light was a wave by showing that it wasn't composed of "parts". If it were, then it wouldn't matter how many times we split it up, made the parts hit one another, etc., we would still get just as much total "light" as we started with. However, if light were a wave, then splitting these waves at particular angles, such that they would later combine, would mean we could end up with less or more than we started with, and that we could detect this using something like film for a final screen, because we'd see the places where the newly combined (or subtracted/canceled out) wave hit the screen.

Young showed that light, like sound, doesn't behave like water molecules or potato bullets or any other particle, because we can detect destructive or constructive interference.

Now we have a problem. After Einstein explained the problem with light hitting metal, and declared light to be made of quanta, or "parts" which he called photons, everyone (literally everyone, it was amazing- the whole world cried out at once, creating acoustic strings which cancelled out cats) said

"WAIT! You can't just declare light to be made of particles, because Young showed it behaves like a wave!" And Einstein replied "Listen, you dolts, why do you think expressions like "He's no Einstein" exist? It's because I'm the genius, not you, so sit down and shut-up." (I'm translating the German here; other less accurate translations include "God does not play dice" and "Is the moon still there when you don't look at it?").

But Bohr (German for "a bore" or "someone who won't listen to reason or Einstein") would have none of this. So he went back to Young's experiment, back to Hamilton equations of motion, and back to his Maxwell coffee. And, with this legal addictive stimulant coursing through his viens, he irrationally concluded that the moon isn't there when you don't look, that cats are both alive and dead, and that if a man says something and there isn't a woman around to hear him he's still wrong.

We all know that the last conclusion is sound and coheres with our everyday experience, but the other two are ridiculous.

Bohr, however, went straight to wikipedia and looked up "quantum", "double-slit", and "photon", printed out a bunch of material, and plopped it down in front of Einstein. Einstein refused to look, so Bohr took a bunch of other physicists to Copenhagen, where he knew that although certain hallucinogens and similar susbtances are illegal, the police tend to turn a blind eye. He first passed around some of these substances, and then the papers he had printed out, and the physicists said "woah, man! This is, like, totally tubular! It's like there are these vibrations between us that we can't see! But we're all, like, "connected" and stuff". So they all signed a document, which was a census or list of names. Unfortunately, there was some confusion because when Bohr called up Einstein to rub his face in it, and Einstein called everyone else, something garbled from static interference and the fact that Einstein said "Bohr has no common sense" and "...they all signed a census" got confused, becoming first "common sense-less consensus" and then just "consensus". Today, this Copenhagen consensus is called "the Copenhagen interpretation." But nobody knows what it is because all the physicists forgot what happened.

On Bohr's pages were the descriptions of various experiments like Young's but very different. They showed that light could indeed behave like a wave, and like a particle. But they also showed:

1) If you fire individual photons at a screen with multiple slits, and you don't look at them, you can detect them on some screen, like film, ending up one at a time. But if you fire enough of them, these spots end up showing a weird pattern: the particles don't go through slits, because if they did we'd no where they'd land, and they aren't there. They end up in weird places they aren't supposed to.

2) These "weird places", or rather the spots on the film, eventually become identical to what we'd get if we just shown a flashlight in the experimental set-up Young designed. In other words, these individual spots not only show up where they aren't supposed to, they eventually become the "wave" pattern we could have detected all at once just by shining light rather than worrying about photons.

3) If you want to know what's going on here (i.e., how are these spots appearing where they aren't supposed to be) and you place a camera outside one or more slits, the pattern vanishes. Instead, each photon goes right where it is supposed to.

4) If you get really inventive, and you try to trick what are clearly tiny fairies (or possibly pixies, or "will-o'-the-wisps; classification of mythical, real creatures is really in its infancy), you will be unable to. So if, for example, you start out firing photons and watching the weird spots appear where they shouldn't, but in mid-stream while some are already headed to the film to appear where they shouldn't, you lift the film. Behind the film you have two lab partners with super-vision goggles, who have been waiting for this, and who have been staring in a particular direction. Now that the film is removed, that direction allows them to see what's happening right after the mystical photons interact with the slits, and catch them being where they aren't supposed to be. But you can't. Because somehow these photons knew you intended to do this, and instead behaving like their buddies were a nanosecond earlier, they are suddenly Mr. & Ms. Photon (and their four children, Peter, Susan, Edmund, and Lucy), right where they are "supposed" to be, behaving like any well-bred, decent, moral, "traditional" particles should.

 

[PolyHedral]

And thus we conclude that reality is made of probabilistically interacting field objects that propagate in a wave-like manner.

 

[idav]

On Bohr's pages were the descriptions of various experiments like Young's but very different. They showed that light could indeed behave like a wave, and like a particle. But they also showed:

I appreciate the lengthy explanation though I still don't see any problem with what I've stated.

1) If you fire individual photons at a screen with multiple slits, and you don't look at them, you can detect them on some screen, like film, ending up one at a time. But if you fire enough of them, these spots end up showing a weird pattern: the particles don't go through slits, because if they did we'd no where they'd land, and they aren't there. They end up in weird places they aren't supposed to.

Yes, quite the conundrum. The experiments verify that the particle is acting as a wave so how are the photons landing "where they aren't supposed to"? They land in the same random places that any wave would if you were to shoot more photons at once so I don't see the issue.

2) These "weird places", or rather the spots on the film, eventually become identical to what we'd get if we just shown a flashlight in the experimental set-up Young designed. In other words, these individual spots not only show up where they aren't supposed to, they eventually become the "wave" pattern we could have detected all at once just by shining light rather than worrying about photons.

Right noted above.

3) If you want to know what's going on here (i.e., how are these spots appearing where they aren't supposed to be) and you place a camera outside one or more slits, the pattern vanishes. Instead, each photon goes right where it is supposed to.

The problem is if you break the quantum state of the particle then it just goes "where it is supposed to". That means it was always a particle to begin with. When if fails at having the inexplicable quantum wave effect that is what should happen. As long as it is still a wave it and not broken by observing wrong, then the photons will act as particles that are in a wave state (same as you have quoted before, just described differently).

4) If you get really inventive, and you try to trick what are clearly tiny fairies (or possibly pixies, or "will-o'-the-wisps; classification of mythical, real creatures is really in its infancy), you will be unable to. So if, for example, you start out firing photons and watching the weird spots appear where they shouldn't, but in mid-stream while some are already headed to the film to appear where they shouldn't, you lift the film. Behind the film you have two lab partners with super-vision goggles, who have been waiting for this, and who have been staring in a particular direction. Now that the film is removed, that direction allows them to see what's happening right after the mystical photons interact with the slits, and catch them being where they aren't supposed to be. But you can't. Because somehow these photons knew you intended to do this, and instead behaving like their buddies were a nanosecond earlier, they are suddenly Mr. & Ms. Photon (and their four children, Peter, Susan, Edmund, and Lucy), right where they are "supposed" to be, behaving like any well-bred, decent, moral, "traditional" particles should.

No, no tiny fairies necessary. It is a particle acting like a wave, very simply put. Same thing would happen to a single water molecule within a classical water wave. If you were to follow the molecule it would land where it shouldn't because it is within water with other molecules that are interfering. The difference with the photons is we can't even see the wave until the evidence pops and the screen and more importantly a single photon has the wave properties without needed a ton of them like that of the classical water wave.

 

[idav]

And thus we conclude that reality is made of probabilistically interacting field objects that propagate in a wave-like manner.

Pertaining to freewill, does/can our brains do thoughts and choices like that?

 

[PolyHedral]

Pertaining to freewill, does/can our brains do thoughts and choices like that?

Our brains are those things. Because everything is built of quantum objects.

 

[crossfire]

The problem is if you break the quantum state of the particle then it just goes "where it is supposed to". That means it was always a particle to begin with. When if fails at having the inexplicable quantum wave effect that is what should happen. As long as it is still a wave it and not broken by observing wrong, then the photons will act as particles that are in a wave state (same as you have quoted before, just described differently).


No, no tiny fairies necessary. It is a particle acting like a wave, very simply put. Same thing would happen to a single water molecule within a classical water wave.

OK, you lost me here. Water within a classic water wave winds up in about the same place it started after the wave passes.

If you were to follow the molecule it would land where it shouldn't because it is within water with other molecules that are interfering. The difference with the photons is we can't even see the wave until the evidence pops and the screen and more importantly a single photon has the wave properties without needed a ton of them like that of the classical water wave.

The wave properties are not intrinsic to the water molecule, unlike with the photon. The wave vector properties are what defines a photon, as it has no mass, and no electric charge. The wave defines the "particle," not vice versa.

 

[LegionOnomaMoi]

I appreciate the lengthy explanation though I still don't see any problem with what I've stated.

Then I have failed, alas. Luckily, I'm used to failure.

The experiments verify that the particle is acting as a wave so how are the photons landing "where they aren't supposed to"? They land in the same random places that any wave would if you were to shoot more photons at once so I don't see the issue.

They don't land in "random" places. That's where the wavefunction comes in. In classical physics a wavefunction described light the way it did sound. And when we just repeat Young's experiment (or something like it) the classical wavefunction works just fine. If we have the right measurments characterizing the wave (i.e., wavelength, frequenty, amplitude), we can set up the experiment with particular angles and all the necessary precision to use the classical wavefunction and know in advance what the "interference pattern" will look like.

Simply put, the classical wavefunction predicts the pattern we will get.

The problem is, this classical wavefunction doesn't work for photons when we simply detect them as "spots" on a screen. But we can modify it. Before, the lightwave was split in two, with one wave going in one direction and one going in the other. So we needed two wavefunctions to describe (or predict) the interference pattern. Now, we only have a single photon at a time.

This is the important part: if we treat the photon as if it were going through both slits, we can describe a single photon's state as the sum of two "classical" wavefunctions. The wavefunction now describes the photon traveling in two places at once, and using this we can predict the interference patterns we get.

So it isn't "random".

The problem is if you break the quantum state of the particle then it just goes "where it is supposed to". That means it was always a particle to begin with.

Here's the problem: who says it is "supposed to" act like a particle, or that when we detect interference, it means the light wasn't going "where it was supposed to"? In other words, now that we have our new wavefunction (which, again, describes the state of a single photon as being in more than once place at the same time), we set up the experiment with the slits and the detection screen, and we use the wavefunction to predict the interference pattern just fine.

If we observe the particle, the wavefunction doesn't work anymore. Instead, photons go where we didn't predict.

So, which describes how the photon is "supposed to" behave? The wavefunction, which works when we don't interfere with the experiment, or the incorrect use of classical mechanics (because in classical mechanics, the equations of motion used for particles work whether you observe or not, and this isn't what we have here)?

As long as it is still a wave it and not broken by observing wrong, then the photons will act as particles that are in a wave state (same as you have quoted before, just described differently).

Description is everything. There is all the difference in the world between saying it is a wave but is behaving like a particle (and vice versa), and saying it is a wave (or is a particle). My quote simply said that it behaves like both at the same time, not that is was both.

A sleeping cat may look dead, but we don't say "the cat is alive, but it is behaving dead". Likewise, we don't say "the photon is a wave but behaving like a particle."

It is a particle acting like a wave, very simply put.

Then let's try an experiment..

I have my sound gun again, and I'm armed with my "classical" wavefunction along with all the necessary variables describing how I set up the experiment (where the slits are, how many of them, etc.).

I hit the "splitting" screen with my sound wave, and I get my detection pattern I predicted.

I do the same thing with a laser gun, but now I use my new quantum wavefunction as I fire photons at my splitter. Once again, I get the pattern predicted.

I do the same thing again, and I start to get the pattern I predict, but right before a stream of "photons" (described perfectly by my new wavefunction as being in multiple places at once) actually get detected (i.e., they have already hit the splitting screen), I unveil a camera to watch these "quantum states". But they aren't there. Instead, my wavefunction fails, the pattern stops, and I get the wrong results. Why?

Let's make it even simpler, and add some "graphics". For the "particle"-like photons, I'll use these ~ ~ ~ to represent them. For the "in two places at once quantum state" photons, I'll use these : : : : to represent them. This } wil be the "double-slit" screen, and this | will be the detection screen.

So I start my laser gun up and begin firing photons-

~~~~~} : : : : : : : : : : |

I can't "see" the ::: (quantum states), but I detect them on the screen. I continue to do this

~~~~~} : : : : : : : : : : |
~~~~~} : : : : : : : : : : |
~~~~~} : : : : : : : : : : |

and it continues to work like I want, but all of the sudden I introduce unveil my camera (represented by ^ and we have to imaginge that this |^ represents the camera behind the screen but also above it, looking at the incoming "quantum state photons"). So, again, I'm continuing above and then unveiling my camera like so

~~~~~} : :__________ |
~~~~~} : : : :________|
~~~~~} : : : : : : :____|
~~~~~} ~~~~~~~~~~~~ |^

The above is supposed to represent the incoming "quantum state photons" (I use these _____ only because if I just use the spacebar the spaces are automatically deleted). I know the "quantum state photons" are supposed to be there, because in reality I haven't ever stopped shooting at the double-slit screen. In other words, although the depiction above shows the "quantum state photons" I'm expecting, in reality there are "quantum state photons" ahead of these which do hit the detection screen and I do detect my pattern. This time, I will put in parentheses the "quantum state photons" that I do detect:

~~~~~} : : ( : : : : : : : ) |
~~~~~} : : : : ( : : : : : ) |
~~~~~} : : : : : : ( : : : ) |
~~~~~} ~~~~~~~~~~~~ |^

The instant the last of the three "quantum state photons" from the 3rd row are detected, my camera goes up to see the incoming "quantum states." Only they aren't there. Not only that, I have no evidence that they ever were. They should have been, because their pals in front are acting just like I predicted with my new "photons are in more than one place at the same time" wavefunction. But when I try to seem them land, I see a stream of individual photons all in the wrong places.

How did they know I would put up that camera?

Same thing would happen to a single water molecule within a classical water wave. If you were to follow the molecule it would land where it shouldn't because it is within water with other molecules that are interfering.

1) Technically, water is never a wave. The only thing that is a wave when it comes to water is the motion, not the actual water. I cannot describe a single water molecule at all with classical waves. I can't describe water at all with classical waves. I can only describe the motion of the water with classical waves, not the water itself.

2) You missed something in my description (understandably, it was long). So in brief: interference is not the same as displacement or "being in the wrong place". It is fundamentally different. Wave interference literally creates alternate waves. Destructive interference causes waves to "cancel out" (either partially or wholly), and constructive interference makes "bigger" waves.

The interference is not about movement, but about creating something "new" which is more or less than what we had before.

So to use water molecules as an analogy, I'd have to say certain molecules were suddenly added or suddenly replaced.

 

[idav]

This is the important part: if we treat the photon as if it were going through both slits, we can describe a single photon's state as the sum of two "classical" wavefunctions. The wavefunction now describes the photon traveling in two places at once, and using this we can predict the interference patterns we get.

So it isn't "random".

I will need to digest all that some more (especially the different ways waves interfere with each other) but I'd like to quickly address this part as it addresses a possible misunderstanding.

What I believe to be happening is that the wave aspect of the photon is passing through both slits while the photon actually goes through one slit. The wave interference is from something that isn't actually there. I don't think it is random either just hard to predict without more data. Treating it as if the photon actually went through both slits is not practical but it does give at least the concept we are trying to tackle(ie a photon seeming to be in two places) and I see where you went with it then being predictable.

Perhaps you can see where our disconnect may be?

 

[LegionOnomaMoi]

I will need to digest all that some more (especially the different ways waves interfere with each other) but I'd like to quickly address this part as it addresses a possible misunderstanding.

Sounds more than fair to me.

What I believe to be happening is that the wave aspect of the photon is passing through both slits while the photon actually goes through one slit. The wave interference is from something that isn't actually there. I don't think it is random either just hard to predict without more data. Treating it as if the photon actually went through both slits is not practical but it does give at least the concept we are trying to tackle(ie a photon seeming to be in two places) and I see where you went with it then being predictable.

Perhaps you can see where our disconnect may be?

I'm going to give a short answer first, and then a more detailed an more accurate one after.

The short answer is that there is no "wave aspect" of the photon, but rather there is only the wave aspects of what we sometimes detect as particles. This is nonlocality. Quantum "objects" are not in one place, but many. And not only is this not random, but we can know in advance what kind of "pattern" will appear. That's what the wavefunction is for: knowing what we will end up observing or measuring.

That's the short answer.


However, something about the nature of quantum states, quantum entanglement, and all the other weird things about quantum theory conflicts with everything we see every moment of every day. We do not see things popping into existence over here, or being in several places at once. I don't have to worry about my arm suddenly appearing four miles away. Something about the way in which the quantum world "joins" together to become the world we experience makes the nonlocality of the quantum world "decohere" or become so minimal that we don't observe its effects.

This is the rather fundamental problem with quantum physics. We have a wavefunction, which completely describes the state of some quantum system, but it does so by saying it is in more than one place at once.

When we try to "see" the quantum state directly, it appears as if there never were any. When we set up an experiment to detect the way we would have an interference pattern if two waves combined in a particular way, that's what we see. In both cases, our detection (actually trying to "observe" the quantum state, or trying to detect the two-slit result on a screen) forces a particular result. It "limits" how the photon appears to travel, just as if we only cut one slit or if we cut three. In reality, the "photon" takes all possible routes every single time, but the way we interact with this "state" limits what we see, not what happens.

Which brings us to another (related) fundamental difficulty with quantum theory. In classical physics, the goal was to have an "isolated system". That is, whether I'm observing planets or cars on a road, I want ensure that no "outside" variables are messing with my system and therefore my results. Sometimes this meant "approximating" an isolated system, because as much as we would like to treat (for example) our solar system as unaffected by the milky way galaxy in order to understand how the planets in out system move, we can't (the milky way galaxy won't kindly stop affecting what we want to model, which is rather rude of it).

However, this approach was very successful, until quantum theory. And even then, for a while we tried to keep that "isolation" approach: the quantum world does its thing, and when we "isolate" some quantum system, it's no different than "isolating" the way two chemicals mix in a lab. The chemicals would mix the same way out of a lab, and the quantum system (so we claimed) is no different.

But it is different. Because everything we use to measure the "quantum system" is made up of matter, which is what quantum theory describes. And while Schrödinger's cat was just a thought experiment, the increase in our ability to manipulate and measure quantum processes has shown that these processes are integral to molecules, cells, molecular dynamics, cellular dynamics, and so on. There is no "isolated" quantum world.

 

[PolyHedral]

There is no "isolated" quantum world.

Isolation is the key to quantum computing.

 

[LegionOnomaMoi]

Isolation is the key to quantum computing.

Not that kind of isolation, as is readily apparent prima facie. Unlike an isolated system in an experiment, in which humans are involved only to observe, measure, deduce, etc., quantum computing is utterly useless if information is not sent from someone or thing to someone or thing such that some sentient system can make use of whatever was computed. That's the opposite of isolation. The importance of maintaining entangled states and the problem of decoherence are certainly a matter of isolation in one sense, but not in the sense which has been used for the past few centuries to describe systems, physics, and the scientific process

 

[crossfire]

So photons are actually virtual particles that manifest for the purpose of energy transfer! {*doh*}

 

[LegionOnomaMoi]

So photons are actually virtual particles that manifest for the purpose of energy transfer! {*doh*}

Clearly you haven't been paying attention. They are fairies (or, to be more technical, they are instantiations of the genus fae). I thought I made that perfectly clear.

 

[crossfire]

Clearly you haven't been paying attention. They are fairies (or, to be more technical, they are instantiations of the genus fae). I thought I made that perfectly clear.

:sorry1:

 

[LegionOnomaMoi]

:sorry1:

It's ok. I'm constantly misunderstood (which explains why every time I seem to be wrong, it''s really just a misunderstanding, because what I meant to say was right, even if i didn't know what that entailed).

 

[crossfire]

It's ok. I'm constantly misunderstood (which explains why every time I seem to be wrong, it''s really just a misunderstanding, because what I meant to say was right, even if i didn't know what that entailed).

Are you certain you are not a nebulous mystic? :angel2:

 

[LegionOnomaMoi]

Are you certain you are not a nebulous mystic? :angel2:

I'm certain I'm not. However, there are various versions of me which claim I am. Don't listen to them. They are my superimposed quantum state liars.

 

[crossfire]

I'm certain I'm not. However, there are various versions of me which claim I am. Don't listen to them. They are my superimposed quantum state liars.

Ahh--you get your spirits from a bottle--gotcha.

 

[PolyHedral]

This is unsatisfactory if quantum mechanics were to be internally coherent and autonomous from classical mechanics."

...? Quantum mechanics is 'autonomous' from CM: it's a different theory. The construction you use has no bearing on the theory's validity.

Besides, your source doesn't appear to object to the idea I mentioned: that CM is the result of a QM with vanishingly small h. If that's true, then that's the answer to the question: there is no ontological boundary between quantum and classical mechanics. The only boundary epistemologically is the complexity and error margins at which the approximation produced by classical mechanics is an accepted compared to the additional computation time of QM.

So sharp a division about what appears to be a reasonably well-defined question is all the more striking given how much agreement there is otherwise, for all parties to the debate in this book are agreed on realism, and on the need, or the aspiration, for a theory that unites micro- and macroworlds, at least in principle."

Nobody has given me a good reason to believe that quantum mechanics is not only that theory, but is actually what it says on the tin: the formalism of QM is how the universe works.

So the QCC problem is trivial? Or perhaps you mean trivial for something like the brain? In which case you might want to tell the researchers who published the study Quantum-classical correspondence in the brain: scaling, action distances and predictability behind neural signals

Or perhaps this study:
"The boundary between quantum theory and classical physics is still largely unknown. Quantum theory obviously applies on length scales smaller than atomic radii but beyond that it is not entirely clear where it should be superseded by Newtonian mechanics.

As mentioned, IMO there is no such point. Why would there be? The domain in which QM produces correct results is a superset of that in which classical mechanics produces valid results.

The conceptual leap associated with this abstraction is hard to overestimate. In fact, the discussions regarding the 'interpretation of quantum mechanics' that have occupied countless physicists and philosophers since the early years of quantum theory are to a large part rooted precisely in the question of how to relate the abstract quantum state to the 'physical reality out there.' (pp. 14-15)
from Schlosshauer's Decoherence and the Quantum-to-Classical Transition (from Springer's monograph series The Frontiers Collection; 2007):

"Exactly as it appears." It's not like the universe can't be a line through Hilbert space.

It's hard to claim that QM is reductionist, when the mathematical models have no agreed upon relation to reality. It's akin to claiming conscious experience is reductionist because I can reduce it Psi. What is Psi? It's conscious experience. Reduction complete.

All of the objects in QM's formalism are constructed out of natural numbers. (Sure, complex matrices are not at all similar to natural numbers in behaviour, but they're constructed out of them.) That's pretty much as reductionist as you get.

In the philosophy literature...

The philosophers wouldn't know a self-adjoint operator if it snuck up and bit them on the behind. Also, what sense of pluralism does it mean? There are many. (...*badum-tish*)

Apart from the QCC issue (see the links in my post above):"the problem that quantum mechanics faces — the 'measurement problem' — is that it sometimes assigns the wrong state to some systems. (As we shall see, the name 'measurement problem' is misleading, because it suggests that the problem occurs only when one makes a measurement, whereas the problem is, in fact, generic.)" (from W. M. Dickson's Quantum Chance and Non-locality: Probability and Non-locality in the Interpretations of Quantum Mechanics).

I've only ever seen the "measurement problem" refer to the fact that measuring systems disturbs them. Therefore, I have no idea what Dickson's using the term to refer to.

Call me crazy, but if they are giving out nobel prizes for scientists who use quantum mechanics to understand fundamentals of biology, then even if one knew next to nothing about physics the idea that quantum processes were at play here seems a likely conclusion.

I don't believe I claimed otherwise. I only said that only electromagnetism was important for computing a cell's workings. Since gravity has no significant effect and the two intra-atomic forces operate on a scale smaller than all atoms' Compton radius, I stand by that.

"This formulation of the measurement process is known as the collapse of the wavefunction, and it is a clearly non-unitary process which formally completes the Copenhagen interpretation. The problem with this description is that does not solve anything." (from p. 12 of Jasper van Wezel's Quantum Mechanics and the Big World; Leiden University Press, 2007).

I agree entirely.

For many physicists, this mystery, the quantum enigma, is best not talked about. It displays physics’ encounter with consciousness. It’s the skeleton in our closet."

Conciousness is irrelevant - wave-functions collapse when observed. Observers can be "sufficiently complex" automata for all the interpretation cares. But, of course, I don't believe in collapse. :flirt:

The crucial question is: How does one determine the transformations A → ΨA and B → ΨB? These transformations transcribe procedural descriptions of the manner in which technicians prepare macroscopic objects, and recognize macroscopic responses, into mathematical functions built on the degrees of freedom of the (microscopic) prepared and measured systems. The problem of constructing this mapping is the famous “problem of measurement” in quantum theory." pp. 53-54 of Mind, Matter and Quantum Mechanics (Springer, 2009)

I don't see the problem. It is clearly possible to do consistently, as per the example. If it were not, surely the theory would not provide answers as successful as they are?

That's simply not true. Either part actually (that the idea is non-sensical and that it is somehow different in a "non-Copenhagen" interpretation). I went into this in great detail right before:

http://www.religiousforums.com/forum/3138784-post173.html
http://www.religiousforums.com/forum/3138787-post174.html
http://www.religiousforums.com/forum/3139548-post175.html

You never responded to any of the research cited.

Time has been unfortunately short. There are not enough hours in the day.

[non-locality]

Do global hidden variables count as "non-local?"

Not multiple "identical" so much as "indistinguishable". The "identical" bit was for illustrating purposes. The incredible difficulty of nonlinear dynamics is hard enough when you can describe the "bodies" of your system. That's "distinguishable". You can't do this for numerous many-body problems.

I don't see the difference. I understood that the mathematics of lots of indistinguishable particles intermingling was already built into the equations.

I did explain. You didn't like the explanation because it contradicted computer science definitions of models. I would be happy to describe them again, and in greater detail, if you would point out what part of the previous explanations you did not understand.

For one thing, it is neither time-invariant or including time as a parameter.

It has nothing to do with that. In fact, we aren't exactly sure what it has to do with because there is no agreement as to whether the wavefunction is actually a probability function of finding a particle or is the superpositioned particle which has a physical reality contrary to all reality as we know it.

In terms of expectations, what's the difference?

The fundamental difference between classical and quantum theory is that of measurement: in the former, you describe a system through measurements of variables which correspond to physical reality. In the latter, you can't. Any measurement changes the physical reality. It determines it.

Isn't that true of a really, really chaotic classical system too? Your measurement "changes" the reality from epistemologically (though not ontologically) random value it was into a definite measurement.