Quantum decision affects results of measurements taken earlier in time

reply to post by Americanist

Remind yourself what is being used as an observer

What do you mean exactly in regards to the experiments I mentioned. If you mean that the observing device is making the interference pattern collapse, you are wrong, the experiments I posted prove that it doesn´t.

About the vid you posted, I don´t really see the significance. The knowledge that particles can behave like waves is a hundred years old. It sure didn´t explain anything about why that is, from what I saw.

They also mentioned you could see the waves, but it seems pretty obvious that it are the same ripples as when you throw a rock in a pond, I´m puzzled about what this has to do with Quantum Physics..

Although the interlocking of the particles does look like entanglement, and the fact that they follow certain paths is strange too. I wonder if it maybe has something to do with the placement of the device that is causing the vibrations.

Also the double slit setup didn´t show anything remarkable. I would like to have more information on this before I can say anything more about this.

I also don´t see the relevance with what I posted.

reply to post by aboriginee

But in the delayed choise quantum eraser experiment the interference pattern appears, although the particle has been measured. The which-path-information, that simultaniously can be observed on the first detector, will then be erased shortly after that.

No you misunderstood my friend. At the time the particles hit the screen the Which path info was available, wich should result in a non interference pattern on the screen. They "erase" the Which path info after the particles have already hit the sreen.

They expect to see a non interference pattern, however when they look at the screen afterwards, there is an interference pattern on it.

This is impossible, it should have been a non interference pattern. The only conclusion is that the pattern somehow changed through time, and adapts to what the experimenter knows.

Why else did they make this conclusion,

Doing so appears to have the bizarre effect of causing the outcome of an event after the event has already occurred. In other words, something that happens at time t apparently reaches back to some time t - 1 and acts as a determining causal factor at that earlier time.

Are you going to argue against that?

Also what did I misunderstand about this, I didn't even say anything in particular about this part,

To me it seems, that you`ve misunderstood something. Scully and Drühl observed first, that when the which-path-information is obtained, that there is no interference pattern. And when they erase the which-path-information, the interference pattern, that was there before the which-path information was given by measuring, shows up again - so far nearly similar to the double-slip-experiment.

So where are you guys now? You were so sure about yourselves.

Nothing but silence now. Hurts don't it, to have your paradigm shattered.

I would see it as a positive thing.

reply to post by RandomEsotericScreenname

So where are you guys now? You were so sure about yourselves.

Nothing but silence now. Hurts don't it, to have your paradigm shattered.

I would see it as a positive thing.

What callow arrogance. Some of us have lives to live, you know.

Anyway, now that I'm back, let me address a few of your more amusing statements:

The way these exp. are setup is that they fire a single particle, this is controlled, therefore it shouldn´t create an interference pattern.

I am aware of the experimental setup. If you think it shouldn't create an interference pattern you are clearly an innocent in quantum mechanics. Would you care to explain why it shouldn't?

I feel that the Quanum Eraser exp. and the Delayed Choic QE exp prove that consciousness is definately involved. The availabilty of the Which Path info is what matters. To who or what would that matter, except consciousness? In the DCQE exp the pattern on the screen even adapts to what the experimenter knows, changing the result from the past.

These results don't prove that consciousness is involved in anything but the interpretation of the experimental results. If you disagree, explain why – in your own words, please – and I will then show you exactly how and where you are mistaken.

It's all about consciousness.

Ah yes. You decided that, simply because I acknowledge the solipsist position as unfalsifiable, I am testifying to the suzerainty of mind over matter. I am doing nothing of the kind.

I urge you to explain why it must be 'all about consciousness'. If you can come up with an argument that has not already been advanced a dozen or more times upon ground that has been trodden into a veritable mire by philosophers down the ages, you will deserve the appellation of genius. If you can come up with a conclusive argument in favour of that position, you will deserve the appellation of God.

The only possible explanation is that the single particle goes through both slits, interferes with itself, and creates an interference pattern. When we observe the screen it has already happened. We were not observing the process, only the result.

The 'only possible explanation', eh?

If you had addressed yourself to the question I asked you earlier – define a photon – you would soon have seen that your interpretation is very far from being the only possible one. You think a subatomic particle is a tiny little bullet, don't you?

reply to post by Astyanax

What callow arrogance. Some of us have lives to live, you know.

Ok, I apologize, but people usually come online again after a few days. Still convenient you are suddenly here after I posted that, still saying nothing and not responding directly to what was said. Only responding back with questions. why not directly debunk me?

I am aware of the experimental setup. If you think it shouldn't create an interference pattern you are clearly an innocent in quantum mechanics. Would you care to explain why it shouldn't?

Interference suggests that there is more then one particle, interacting with the single particle. If I'm a noob then so are the experimenters of these experiments.

These results don't prove that consciousness is involved in anything but the interpretation of the experimental results. If you disagree, explain why – in your own words, please – and I will then show you exactly how and where you are mistaken.

I already gave the answer in that piece, to what other force would it matter if the info is kown to the experimenter, and why does the result adapt to what the experimenter knows? I look forward to your explanation.

If you had addressed yourself to the question I asked you earlier – define a photon – you would soon have seen that your interpretation is very far from being the only possible one. You think a subatomic particle is a tiny little bullet, don't you?

Then what is a single photon?

And since you didn't respond to this, I'll take it you found that less amusing?

Doing so appears to have the bizarre effect of causing the outcome of an event after the event has already occurred. In other words, something that happens at time t apparently reaches back to some time t - 1 and acts as a determining causal factor at that earlier time

Btw, using "fancy" words doesn't make you right, nor does it impress me.

Ah yes. You decided that, simply because I acknowledge the solipsist position as unfalsifiable, I am testifying to the suzerainty of mind over matter. I am doing nothing of the kind.

Sofar you have said absolutely nothing of substance.

Originally posted by RandomEsotericScreennameto what other force would it matter if the info is kown to the experimenter, and why does the result adapt to what the experimenter knows?

I am thinking that this is the key in this experiment. Also that this is about to blow science wide open.

That's because so far, science has been based on the premise that we are totally objective observers and that everything subjective must be ruled out. These experiments are proving that not only are the scientists themselves "entangled" in the experiment, but they actually play a role in determining the outcome.

Or in other words, everything is subjective and there can be no completely objective observer.

If that's true, then scientific theory will be turned on its head and we can start to make some amazing progress

reply to post by RandomEsotericScreenname

Interference suggests that there is more then one particle, interacting with the single particle.

Interference implies waves, not particles.

I already gave the answer (to your question) in that piece

Oh no, you didn't. You have to explain why you think quantum eraser experiments imply what you think they do about consciousness. It is not simple, and you haven't done it yet – you're still going on about particles knowing things and forces having desires.

To what other force would it matter if the info is known to the experimenter, and why does the result adapt to what the experimenter knows? I look forward to your explanation.

Forces have no desires, so information cannot 'matter' to them.

As Wikipedia very correctly puts it,

The fundamental lesson of Wheeler's delayed choice experiment is that the result depends on whether the experiment is set up to detect waves or particles.

There's your answer.

By the way, this thread actually is about a delayed-choice experiment, though not the one you have read about. Interestingly, there is no human element in this experiment. It is all machinery. Yet even so, the same quantum paradoxes are shown to occur. If consciousness is the mediator of quantum events, how come?

To help you answer that (and I do want an answer), here is a scientifically respectable description of the quantum eraser experiment. Please explain how it squares with your 'consciousness theory'.

Oh, and I'm still waiting for your definition of a photon.

*

reply to post by OccamsRazor04

I am thinking that this is the key in this experiment. Also that this is about to blow science wide open.

John Archibald Wheeler proposed the experiment and predicted the results in 1978. No-one seriously disputed them; they arise from principles known to science since the 1930s.

It was only in 1999 that apparatus became available that could test the predicted results. They came out as predicted, further confirming that quantum mechanics is an accurate description of the phenomena to which it is applied. No-one was surprised.

All the fuss came later, when people who don't know any physics heard about the experiment and the results and jumped to all kinds of crazy conclusions about them.

reply to post by Astyanax

Interference implies waves, not particles.

LOL, that's just it, they fired a SINGLE particle, so how can it turn into a wave? Only if it goes through both slits and interferes with itself. You know that a wave can't be wave if it is a single particle?

And don't say it is because of wave/particle duality cause that is not an explanation, it is just a description. The experiments I posted explain why there is wave/particle duality.

Remember, this is what you said,

I am aware of the experimental setup. If you think it shouldn't create an interference pattern you are clearly an innocent in quantum mechanics. Would you care to explain why it shouldn't?

So now that I have explained why it shouldn't, I'll be expecting your reply on that.

Oh no, you didn't. You have to explain why you think quantum eraser experiments imply what you think they do about consciousness. It is not simple, and you haven't done it yet – you're still going on about particles knowing things and forces having desires.

Oh I clearly did. The results clearly adapt to what the experimenter knows. Are you denying that the result matches exactly with the experimenters knowledge at that time? It clearly does.

Forces don't have desires, I didn't say that, that is the whole point I'm making. Because they don't, the only explanation is that the particles adapt to consciousness.

You have to at least admit that you have no explanation for these bizarre results, yet you refuse and act like this is normal or expected, but it can't be explained by anything else but consciousness, it is in fact very simple and blatantly obvious to anyone that is not stuck in his own paradigm.

Once again you refused to respond to this,

Doing so appears to have the bizarre effect of causing the outcome of an event after the event has already occurred. In other words, something that happens at time t apparently reaches back to some time t - 1 and acts as a determining causal factor at that earlier time

Please explain how this happens without consciousness being the cause of it. I'll be glad to hear your alternative explanation.

The fundamental lesson of Wheeler's delayed choice experiment is that the result depends on whether the experiment is set up to detect waves or particles.

I wasn't talking about Wheelers delayed choice experiment. I was talking about Delayed Choice Quantum Eraser exp. and the Quantum Eraser exp. They are not the same experiment buddy. Research the right experiments before you start talking again.

By the way, this thread actually is about a delayed-choice experiment, though not the one you have read about. Interestingly, there is no human element in this experiment. It is all machinery. Yet even so, the same quantum paradoxes are shown to occur. If consciousness is the mediator of quantum events, how come?

It doesn't matter what this thread was about, I added to it, and made it clear what I was talking about. Another cop out.

But you are hilarious nonetheless, it is completely obvious that the detectors called Bob, Alice and Victor are checked by human experimenters. Otherwise there would be no experiment and no conclusion.

The choice about entangling the photons at the Victor apparatus was made by a random-number generator, and passed through a tunable bipartite state analyzer (BiSA). The BiSA contained two beam-splitters that select photons' paths depending on their polarization, along with a device that rotated the polarization of the photons. Depending on the "choice" to entangle or not, the polarization of the photons from I and II were made to correlate or left alone. Finally, the polarization of both photons at Victor were measured, and compared with the results from Alice and Bob.

Who else was measuring, comparing and watching the results?

To help you answer that (and I do want an answer), here is a scientifically respectable description of the quantum eraser experiment. Please explain how it squares with your 'consciousness theory'.

I was discussing the experiments that I gave you. This is more side stepping. Debunk me on the bases of these experiments which I based my conclusion on.

Oh, and I'm still waiting for your definition of a photon.

Why the side stepping? Why not go ahead and post your definition and debunk me directly? What are you waiting for?

A photon is a particle. I know you are trying to break this down to wave/particle duality.

Once again you have said nothing of substance at all. You are clearly trying to avoid having a real discussion based on what I said and the experiments I posted about.

All I see is a skeptic refusing to discuss the issues at hand because it doesn't fit his paradigm, just like I said in the post you took offense to.

reply to post by Astyanax


Btw, this is a qoute from the link you posted,

One can wonder then, if this perplexing behavior is just due to a disturbance between the "which-way" detector and the photon. The detector might be changing something about the photon which causes it to get off course to its position in the interference pattern. The answer is, as the experiment described in the next section shows, that this is not the case. A "which-way" detector can be designed that in no way disturbs the photon and the same phenomenon is observed.

Also what I have been saying. so if it is not the detector itself that is making the interference pattern collapse, it has to be the "knowing"of the which path info.

If you have another explanation for it I'll be glad to hear it.

It is peculiar then, that the presence of the quarter wave plates causes the s photons to so drastically change their behavior. One can't help but ask, how do these photons know that we could know which slit they went through?

Hmm, that's strange even the "scientifically respectable" research you posted yourself in order to debunk me is suggesting that particles somehow knows what we know.

What did you say to me again?

you're still going on about particles knowing things

Well so is this research you posted, buddy.Did you actually read it or did you just assume it was going to blow me out of the water? This is hilarious.

Now they don't go as far as saying it is consciousness that is causing this, but hey, they are scientists, they don't dare make that step. When you think about it the only explanation is consciousness.

They end with this,

Entanglement seems to play a very important role on the quantum scale of the world, so we need to think about it in new ways. This quantum erasure experiment is one of many experiments being done that provides a way for us to better understand the strange nature of quantum mechanics. We have encountered strange concepts like entanglement and non-locality. Perhaps this is just the beginning of a journey to a deeper understanding of the universe and new discoveries.

Indeed it this, and it will turn out it is all about consciousness, it is the only explanation for these results.

Because we know what the entangled partner did, the other partner adapts to what we know, in these experiments.

Mind Firmly Closed

I know you are going to say that line is meant to be sarcasm, but it is very close to the truth obviously.

I hope I'll be hearing from you soon, so I won't have to call you out again.

reply to post by Astyanax


Btw, the drawings of the setup of the exp. from your link and the explanation seems to be false. He suggests that the interference pattern is created by single photons going through one of the slits at a time, hitting the screen as a single photon, and over time creating an interference pattern, this is completely false.

Single photons go through both slits, interfere with themselves and thus create the interference pattern on the screen., when the which path info is not known.

This is common knowledge in both the exp. I posted about.

so 104 meters of fiber optic cable was needed to produce a lag of 14 billionths of a second, or 14 nanoseconds.

you would need roughly 7428571428.57 meters of fiber optic cable to affect 1 second ago, LOL!

this supports my theory of how time works. yay for me, but too bad i'll die a nobody.

reply to post by RandomEsotericScreenname

And don't say it is because of wave/particle duality cause that is not an explanation, it is just a description.

Further proof of your innocence of quantum mechanics. Why the heck don't you learn the first principles of the science before pronouncing on its most sophisticated implications? Learn what a wave is, what a particle is, and what the Schrödinger equation implies about the relationship between those two entities. When you have done so, come back and we can talk some sense.

I'll be expecting your reply on that.

There it is.

You have to at least admit that you have no explanation for these bizarre results, yet you refuse and act like this is normal or expected, but it can't be explained by anything else but consciousness, it is in fact very simple and blatantly obvious to anyone that is not stuck in his own paradigm.

Enough with the insults. I answered your question with a quote from Wikipedia. These results are normal and expected – to people who have actually studied quantum mechanics, learning from other physicists. To people ignorant of the science, they seem bizarre. And to hell with paradigms; aren't you stuck in yours?

If you genuinely want knowledge, you have gone the wrong way about asking for it. I am happy to share mine with those who ask politely and don't pose as bumptious know-alls. You have no knowledge of quantum mechanics; I have very little, but I have the basics, and know that what I have is academically and empirically respectable. You have nothing but your opinions. Well, you may stew in them for all I care.

One day you may learn the true depths of your ignorance.

reply to post by Astyanax


Hahahahahilarious, again you completely refuse to respond with substance to anything I said. Just completely refuse.

You can't even respond to the fact that your own link debunked what you said. Pathetic, and a blatant admission that you have absolutely no way to counter what I said, and I'm obviously right when I say that you are stuck in your own paradigm.

Like I said, hurts don't it?

Very scientific of you this reaction. 3 posts and you have said absolutely nothing, nada, zilch.

Like this,

Enough with the insults. I answered your question with a quote from Wikipedia.

Lol, did you even read my post? You qouted a piece from an experiment I wasn't even talking about, like I clearly said in my last post.



And what about the ten other things I said?

Just admit that you are completely dumbfounded and left scratching your head.

I'm trying to learn people something, and a true man of science would listen and respond to what was said.

You clearly refuse to do so.

If you genuinely want knowledge, you have gone the wrong way about asking for it. I am happy to share mine with those who ask politely and don't pose as bumptious know-alls.

Oh the irony. I didn't ask you for anything except a proper debunk of my claims. I'm schooling you obviously.

You clearly act like you are some sort of authority, but in reality you can't even engage in a proper factual discussion.

It won't be that long till this all will be seen as self evident. Your loss man.

reply to post by Astyanax

Further proof of your innocence of quantum mechanics.

Please help me then and post the explanation of why there is wave/particle duality.

And to hell with paradigms; aren't you stuck in yours?

If you can debunk my statements, and the factual implications of these experiments, not my conclusion, but the factual results, which you even seem to refuse, I'll concede, like a man of science and... like a man.

You have no knowledge of quantum mechanics; I have very little, but I have the basics, and know that what I have is academically and empirically respectable.

Yep, stuch in paradigm.

These results are normal and expected – to people who have actually studied quantum mechanics, learning from other physicists.

Really, I'll just post this qoute, but there are many more that prove that they are perplexed themselves,

Doing so appears to have the bizarre effect of causing the outcome of an event after the event has already occurred. In other words, something that happens at time t apparently reaches back to some time t - 1 and acts as a determining causal factor at that earlier time

If bizarre means normal and expected, yes then you are right.

If you think that results of events that have already happened, change to exactly correspond with what the experimenter just happens to know in the present is a normal, expected thing, than you are either delusional, or lying.

Originally posted by RandomEsotericScreenname
reply to post by aboriginee

 

But in the delayed choise quantum eraser experiment the interference pattern appears, although the particle has been measured. The which-path-information, that simultaniously can be observed on the first detector, will then be erased shortly after that.

No you misunderstood my friend. At the time the particles hit the screen the Which path info was available, wich should result in a non interference pattern on the screen. They "erase" the Which path info after the particles have already hit the sreen.

They expect to see a non interference pattern, however when they look at the screen afterwards, there is an interference pattern on it.

This is impossible, it should have been a non interference pattern. The only conclusion is that the pattern somehow changed through time, and adapts to what the experimenter knows.

Why else did they make this conclusion,

Doing so appears to have the bizarre effect of causing the outcome of an event after the event has already occurred. In other words, something that happens at time t apparently reaches back to some time t - 1 and acts as a determining causal factor at that earlier time.

Are you going to argue against that?

Also what did I misunderstand about this, I didn't even say anything in particular about this part,

To me it seems, that you`ve misunderstood something. Scully and Drühl observed first, that when the which-path-information is obtained, that there is no interference pattern. And when they erase the which-path-information, the interference pattern, that was there before the which-path information was given by measuring, shows up again - so far nearly similar to the double-slip-experiment.

edit on 28-4-2012 by RandomEsotericScreenname because: (no reason given)

And now I think, you should read my last post once more, which you`ve answered to in the above shown text.
That`s what I wrote and what I meant:
Although the which-pass-information was there and detected by the first detector, the screen showed already an interference-pattern, although this information of interference was given to the particle after that.

And that`s nothing about consciousness.
Quantum-particles don`t act within our time in order to get information, in some regions ore actions they stand above time.

And something about my citation you posted at the end of your above text: Please don`t cut off my texts - the meaning of my statements could change by doing that.

Originally posted by Astyanax
reply to post by aboriginee

 

All the same, we do know something about it. One of the things we know is that it isn't an actual particle travelling through space the way a bullet does. It makes more sense to imagine it as a kind of cloud. The cloud is actually as big as the universe! However, it is so thin as to be almost nonexistent everywhere except in those places the photon is most likely to be found if we look for it. The instant the photon is detected, the cloud collapses to a point – the point of detection – and the photon seems to be a bullet. Weird, no?

Yes, that`s weird and fascinating. Perhaps it`s because of the wave isn`t "captured" within our room and time. It is able to be everywhere simultaniously.

Well, that's not quite right, as my explanation shows. We collapse the wavefunction (the cloud) by observing it. The thing is, this has nothing to do with consciousness. We can't control or predict where the photon is found; we can only predict probabilities.

No, we can collapse the wavefunction only by measuring it, not by observing it.

And about light - when a light-ray is directed towards a double-slit, we can see the wavefunction with our eyes on the screen - that`s the only occasion at which we are able to observe the wavefunction without the necessity of isolating single particles or atoms in order to show or see the possible wavefunction of matter.

The invariance of the speed of light is a fundamental property of nature. It is assumed in all quantum calculations. I don't know if this answers your question – I found it hard to understand. Perhaps you could clarify it a little?

It`s about the special-relativity-theory of Einstein.
When two cars move onto each other, their velocities add up, which can be experienced, if they crash into each other. The speed of light remains the same, independent of our direction and velocity and independent of the velocity of the light-source.
That`s something, which doesn`t match up with the laws of movement within our space.
Light seems to be something, that exists in our space, but doesn`t obey the rules of space.
Therefore it seems to exist within our dimension but also within a dimension above.

Agreed. But time is experienced through change, so it is also the consequence of the objects that exist in space.

Yes, changes in or at quantum-particles happen in space, but don`t always act within the laws of space as being seen in the experiment we are talking about in this thread. Information within particles or between particles often doesn`t travel through our space - and where there`s no space, there`s also no time or no being captured in time.

You're speaking of the consequences of entanglement – 'spooky action at a distance'. This assumes that information is passing from one entangled particle to the other. However, this is not how information normally behaves; it is usually transmitted by material means that obey the laws of classical physics. It seems risky to invoke an extra dimension of spacetime merely to carry quantum information. This kind of speculation takes us beyond the realm of the known; I prefer to leave it to real physicists, who know what they are doing. My knowledge of physics, sadly, does not extend that far.

As we can see in the described experiment, the particles there don`t obey the laws of classical physics too.
The particle knows the next step before it gets the information about it practically.
There are physicists who state, that there is a fourth room-dimension and that time isn`t a dimension of its own. It does exist within our dimension, but it isn`t stable. Near the velocity of light, time passes by more slowly and above the velocity of light it would reverse as Einstein found out. And when it`s not stable it`s no dimension of its own.

reply to post by aboriginee

Perhaps it`s because of the wave isn`t "captured" within our room and time. It is able to be everywhere simultaniously.

Yes, that is correct.

We can collapse the wavefunction only by measuring it, not by observing it.

That is what I meant; the use of the term 'observation' is traditional in English and possibly in other languages as well. I certainly didn't mean it had to be seen by a human observer. In most quantum experiments that is impossible anyway.

Strictly speaking, this is what we mean by 'measurement' or 'observation': we cause the system described by the wavefunction to interact with another system, which imposes fixed values on certain variables in the function. Consciousness certainly does not come into it – I suppose our New Age friend imagines Alice, Bob and Victor as three lab-coated scientists peering into a box, but actually they are just machines.

When a light-ray is directed towards a double-slit, we can see the wavefunction with our eyes on the screen.

More accurately, we see the record of its interaction with an external system. The wavefunction has already collapsed at that point.

Originally posted by Astyanax
The invariance of the speed of light is a fundamental property of nature. It is assumed in all quantum calculations. I don't know if this answers your question – I found it hard to understand. Perhaps you could clarify it a little?

Originally posted by aboriginee
It`s about the special-relativity-theory of Einstein... Light seems to be something, that exists in our space, but doesn`t obey the rules of space. Therefore it seems to exist within our dimension but also within a dimension above.

Oh, no. Light in special relativity is very much a phenomenon in four-dimensional spacetime. The invariance of its speed causes time to dilate and space to contract, and it is these phenomena that compensate for its apparently odd behaviour in relative-velocity calculations.

Changes in or at quantum-particles happen in space, but don`t always act within the laws of space as being seen in the experiment we are talking about in this thread. Information within particles or between particles often doesn`t travel through our space - and where there`s no space, there`s also no time or no being captured in time.

This is wrong, I'm afraid. Quantum particles do act lawfully; it is just that the laws they follow, much like the laws of relativity, don't make intuitive sense to humans. In fact, the behaviour of quantum particles is quite Newtonian except for nonlocality. But the way to cope with nonlocality is simply to think of an entangled pair as a single entity; they are no longer to be considered as two individual particles.

The particle knows the next step before it gets the information about it practically.

Speculation. We do not really know what happens. It is unsafe to apply words 'before' and 'after' to the situation. We don't know enough about time at quantum scales to understand how these words apply.

There are physicists who state, that there is a fourth room-dimension and that time isn`t a dimension of its own. It does exist within our dimension, but it isn`t stable. Near the velocity of light, time passes by more slowly and above the velocity of light it would reverse as Einstein found out. And when it`s not stable it`s no dimension of its own.

You mean 'a fourth dimension of space.' Yes, there are physicists who believe in ten- and eleven-dimensional spacetimes, as well as those who believe that space is two-dimensional and its 3D appearance is just a holographic projection. There are physicists who refuse to believe that time exists at all; this, too, cures the nonlocality paradox, and although it sounds far-fetched, there are ways in which the difficulties arising from this model can be addressed. Loop quantum gravity theories regard matter as braids or knots in spacetime; again, this suggests (to me, at least) that the arrow of time can change direction, or perhaps point in either direction simultaneously.

Allow me to say what a pleasure it is to talk about these things to someone who is actually interested in physics.

Wow so now these particles understand future and past, next we are going to be calling them gods...

Originally posted by AstyanaxConsciousness certainly does not come into it – I suppose our New Age friend imagines Alice, Bob and Victor as three lab-coated scientists peering into a box, but actually they are just machines.

Ok I admit I don't know much about Quantum Physics, but I have studied science. So lets boil this down to the bare basics.

From what I can understand, the only variable in this experiment was whether or not the scientists knew the measurement or not. The machines had already taken the measurement, but the data was erased, meaning they never saw it. Is that right?

If that's the case, I can't see how you can keep claiming that consciousness doesn't come into effect here.

reply to post by Cecilofs

Lets boil this down to the bare basics.

The trouble is, you just can't do that with quantum mechanics.

From what I can understand, the only variable in this experiment was whether or not the scientists knew the measurement. The machines had already taken the measurement, but the data was erased, meaning they never saw it. Is that right?

If that's the case, I can't see how you can keep claiming that consciousness doesn't come into effect here.

It's probably a good idea to make sure you understand the experiment and its setup first. The Wikipedia account is pretty good. You should go and read that (I've linked you to the exact place on the page) before you go on to read the rest of my post.

< >

Back already? Okay, here goes.

As you now know, the 'measurement' is simply a determination of which of two slits a photon passes through on its way to a light-sensitive screen. This is done is by putting opposite polarizing filters in each of the slits. Each filter puts a different 'mark' on a photon as it passes through the slit, so we can see, from the mark, which slit it came through.

If don't put the filters in the slits, we can't tell at the screen which slit the photon came through. An interference pattern appears on the screen despite the obvious impossibility of a particle being in two places at the same time – as it would need to be, in order to interfere with itself.

As soon as we put the filters in the slits, thereby producing information about which slit the photons came through, the interference pattern collapses and all we see is a pattern of dots.

By repolarizing the photon after it has passed through the slits but before it hits the screen, you can bring back the interference fringes. You can even do that by polarizing entangled partners of the original photons that never came near the screen. It makes no difference; but the one thing you can't do is change the pattern on the screen after it has formed. And you can only look at it after it has formed.

Consciousness, therefore, can be ruled out as having any effect on the outcome of the experiment. The whole thing is entirely automatic, done with machines; you could run the experiment overnight, with machines inserting and removing the various polarizing filters and changing screens every so often according to some predetermined schedule or random program, and come back in the morning to read exactly what happened, hour after hour, by looking at the traces on the screens. You would always see the expected result: filters out, fringes; filters in, pattern of dots.

If you want a scientific explanation for what exactly is happening, this gets the basics across pretty well. Be sure to read both answers.