Wave Function Collapse

[sysD]

It is reported that the wave function will collapse when observed or due to environmental interaction.

 

Is it possible that the wave function collapse in an experimental setting is due to electromagnetic interference from a human body?

[swansont]

Possible? Probably yes. It would depend on the details of the experiment.

[sysD]

for example... shrodinger's cat.

when the lid is removed, the environment is no longer sealed.

even in the absence of a measuring device, human EM radiation would collapse the wave function.

 

same premise to explain the double slit experiment.

i'm self-taught in physics, so i doubt this is the actual explanation. i just thought i'd throw it out there

*awaiting nobel prize*

[steevey]

What does it actually mean to determine a particle or collapse a wave function? What makes the distinction between collapsing it and just another event if even machines can do it?

[sysD]

My thinking behind this is that any environmental "noise" will cause a wave function to collapse upon interaction with the particle. (At least in my understanding.)

 

Maybe I should be more specific.

 

Is EM radiation from measuring devices/humans the cause of wave function collapse in the double slit experiment (relating to the observer effect)?

 

Another way of asking this is: Is the observer effect attributable to EM radiation?

Edited March 9, 2011 by sysD

[steevey]

My thinking behind this is that any environmental "noise" will cause a wave function to collapse upon interaction with the particle. (At least in my understanding.)

 

Maybe I should be more specific.

 

Is EM radiation from measuring devices/humans the cause of wave function collapse in the double slit experiment (relating to the observer effect)?

 

Another way of asking this is: Is the observer effect attributable to EM radiation?

 

If the photon hits the electron but hasn't hit your retina yet, will the electron be determined? Also, I don't think just any interaction between particles collapses a wave function otherwise particles couldn't be entangled through close interaction.

Edited March 10, 2011 by steevey

[Mike Smith Cosmos]

If the photon hits the electron but hasn't hit your retina yet, will the electron be determined? Also, I don't think just any interaction between particles collapses a wave function otherwise particles couldn't be entangled through close interaction.

 

Steevey. If I am gaining a good picture of what is going on. I think. The wave function that is associated with the electron is described by Schroenigers equation and plots distance away from ' center of operations' of the electron against the probability of it being there. So I think this fairly wide wave of probability sweeps forward toward the two slits or whatever. If its left alone it sweeps through both slits and interfears with itself the otherside of the slits. Thus producing the interference pattern. I don't think the shreoniger equation brings time into it.

 

Too much messing with the electron ie by shining photons on, or generally intruding on the electrons flight and the wave pattern of the electron gets radically changed, collapsed, or whatever by the wave function of the intruding "thing". If I've got a correct picture that is.

Edited March 10, 2011 by Mike Smith Cosmos

[steevey]

Steevey. If I am gaining a good picture of what is going on. I think. The wave function that is associated with the electron is described by Schroenigers equation and plots distance away from ' center of operations' of the electron against the probability of it being there. So I think this fairly wide wave of probability sweeps forward toward the two slits or whatever. If its left alone it sweeps through both slits and interfears with itself the otherside of the slits. Thus producing the interference pattern. I don't think the shreoniger equation brings time into it.

 

Too much messing with the electron ie by shining photons on, or generally intruding on the electrons flight and the wave pattern of the electron gets radically changed, collapsed, or whatever by the wave function of the intruding "thing". If I've got a correct picture that is.

 

So your trying to say that the photon hitting the electron determines it whether there's an observer or not?

[Mike Smith Cosmos]

So your trying to say that the photon hitting the electron determines it whether there's an observer or not?

 

Yes !

[steevey]

Yes !

 

How is a photon hitting an electron measuring it in any way? And what about the photon itself? Just because a photon hits an electron doesn't mean the photon is determined either.

Edited March 10, 2011 by steevey

[Mike Smith Cosmos]

How is a photon hitting an electron measuring it in any way? And what about the photon itself? Just because a photon hits an electron doesn't mean the photon is determined either.

 

You cant detect the presence of the electron say without looking. To look and see , you need some form of light , even if its ordinary light, UV light or X ray light they are all photons. They all have wave functions, they all have a certain amount of energy. The nearer to x rays the greater the energy. Thats why the dentist runs out of the room when he x rays your teeth. So its like bashing the tortoise with a string of Ping Pong Balls , the tortoise shrinks his head back into his shell. I'm sure there is a mathematical equation for this. Some form of fourier analysis of the two wave functions ( of the observing photon and the electron) perhaps. No doubt Mr Swansont will put me right if not.

Edited March 11, 2011 by Mike Smith Cosmos

[steevey]

You cant detect the presence of the electron say without looking. To look and see , you need some form of light , even if its ordinary light, UV light or X ray light they are all photons. They all have wave functions, they all have a certain amount of energy. The nearer to x rays the greater the energy. Thats why the dentist runs out of the room when he x rays your teeth. So its like bashing the tortoise with a string of Ping Pong Balls , the tortoise shrinks his head back into his shell. I'm sure there is a mathematical equation for this. Some form of fourier analysis of the two wave functions ( of the observing photon and the electron) perhaps. No doubt Mr Swansont will put me right if not.

 

I'm still not seeing why a photon hitting an electron alone would cause either or both of them to become determined. Now that I think about it though, an electron could remain undetermined if only the photon was determined since the photon would only be acting as a particle and therefore be measured as one, unless particles are never determined and we just only see one possible state.

 

Does anyone know of an experiment where someone shines a flashlight at a mirror to see if there's an interference pattern on the other walls what the photons hit after they hit the mirror in a vacuum while no one is looking, also free from any magnetism, with the exception of Earth's since it hasn't messed with the other slit experiments.

Swan or remm, care to say if this experiment or one like this has been done? Cause I can't find anything on one.

 

 

 

Edited March 11, 2011 by steevey

[sysD]

My (vague) understanding is that when a determined particle (in this case, a photon), interacts with an electron probability cloud (wave function), the electron "pops" into existance at the point of interaction.

I have no idea why this is.

[swansont]

My (vague) understanding is that when a determined particle (in this case, a photon), interacts with an electron probability cloud (wave function), the electron "pops" into existance at the point of interaction.

I have no idea why this is.

 

That's one pop-sci/introductory explanation, but the problem with it (and others like it) is that the model one builds from it isn't very useful. It's not that the electron doesn't exist, it's that you don't know where it is. It doesn't have a trajectory, and since it's a wave, "where" isn't a well-defined concept. There isn't information about a "where" unless you hit it with a photon (or another particle).

[Mike Smith Cosmos]

My (vague) understanding is that when a determined particle (in this case, a photon), interacts with an electron probability cloud (wave function), the electron "pops" into existance at the point of interaction.

I have no idea why this is.

 

Whether it is of any use SysD. Whenever anyone speaks of waves I always thing of waves on the sea. Early physics often uses sea waves as a model. The recent Tsunami is a wave example. The source of energy to the wave was a major jolt in the pacific plate. The Tsunami wave could be seen all over the world on TV. If anyone said where is the wave ( equivalent of the electron ) then you could point to the wave on the tv screen.But which part of a wave miles upon miles wide would you point to. Bit difficult as its all over a long wave front. However once the wave is interfered with, ie landfall. It was easy to see exactly where the collapsed wave was. ie JAPAN or even more specifically the northern region which took the brunt . ( electron now , not a wave but a particle - Energy hit that caused an atomic power station to blow up . The model is only of use so far , but it does illustrate the difference of a wave like condition and a particle like condition ( wave fairly benign while out at sea ( boats bob up and down ) destructive or energetic when a particle of confronted enegy ( boats smashed to bits )

Edited March 12, 2011 by Mike Smith Cosmos

[steevey]

That's one pop-sci/introductory explanation, but the problem with it (and others like it) is that the model one builds from it isn't very useful. It's not that the electron doesn't exist, it's that you don't know where it is. It doesn't have a trajectory, and since it's a wave, "where" isn't a well-defined concept. There isn't information about a "where" unless you hit it with a photon (or another particle).

 

Even if you don't know where the electron is, can't you say that when its localized or determined that since its only occupying space as a single point, it is no longer in every possible point, which means there are some places that its not located in or that there are positions it isn't occupying?

 

If I through a rock behind my back, I don't know where it is, but I know its not in every possible place it could be behind my pack since its only occupying a specific region of space, or it has a specific volume and specific dimensions.

Edited March 13, 2011 by steevey

[swansont]

Even if you don't know where the electron is, can't you say that when its localized or determined that since its only occupying space as a single point, it is no longer in every possible point, which means there are some places that its not located in or that there are positions it isn't occupying?

 

If I through a rock behind my back, I don't know where it is, but I know its not in every possible place it could be behind my pack since its only occupying a specific region of space, or it has a specific volume and specific dimensions.

 

Yes. That's not the same as saying it doesn't exist when you can't see it.

[sysD]

Whether it is of any use SysD. Whenever anyone speaks of waves I always thing of waves on the sea. Early physics often uses sea waves as a model. The recent Tsunami is a wave example. The source of energy to the wave was a major jolt in the pacific plate. The Tsunami wave could be seen all over the world on TV. If anyone said where is the wave ( equivalent of the electron ) then you could point to the wave on the tv screen.But which part of a wave miles upon miles wide would you point to. Bit difficult as its all over a long wave front. However once the wave is interfered with, ie landfall. It was easy to see exactly where the collapsed wave was. ie JAPAN or even more specifically the northern region which took the brunt . ( electron now , not a wave but a particle - Energy hit that caused an atomic power station to blow up . The model is only of use so far , but it does illustrate the difference of a wave like condition and a particle like condition ( wave fairly benign while out at sea ( boats bob up and down ) destructive or energetic when a particle of confronted enegy ( boats smashed to bits )

 

 

Thanks; real-life examples are very, very helpful in explaining physical phenomena. Especially those quantum quirks that seem to elude my understanding =)

[Schrödinger's hat]

Bear in mind that's not a very exact analogy as a tsunami is a wave-phenomenon, not a quantum phenomenon (wavefunction), but it has some use.

I find the many worlds interpretation is useful in this regard, especially when considering an as of yet unobserved photon which has interacted with an electron.

 

There is a device called a quantum eraser, I do not know if anyone has built one with the double slit experiment, but instead of talking about spin and things I'll use it as an example, the principle stands even if this experiment would be prohibitively difficult to perform.

 

If one were to fire a photon at one slit during the double slit experiment, but not receive/measure it (including having it interact with any other system you interact with) the whole electron/slits/photon system is still in a superposition.

Because of incompatible variables (Heisenberg's uncertainty principle etc) there will be a way that you can measure the photon which destroys the information about the electron -- I imagine a very precise measure of its momentum would work (this is the prohibitively difficult part, as it would be difficult to make this measurement without knowing where it was, this is why other such experiments tend to use spin entanglement). If you do this erasure of information while the electron is still in flight (ie. you haven't measured it yet) then the interference pattern will be seen even though you made a measurement (providing the results of that measurement don't exist anywhere in the universe)

 

This is why I like to think of things in terms of many worlds, before the measurement you are equally in all the universes where the electron took every path. After you interact with the photon which interacted with the electron you have narrowed down the range of universes this instance of you is in to one of two sets

The ones where it went left

and the ones where it went right

in this case it can't interfere so no pattern is produced

[darkenlighten]

I'm actually creating a separate thread since this one is old: http://www.scienceforums.net/topic/55917-the-wave-function-what-exactly-is-it/

Edited March 22, 2011 by darkenlighten

[Mike Smith Cosmos]

Bear in mind that's not a very exact analogy as a tsunami is a wave-phenomenon, not a quantum phenomenon (wavefunction), but it has some use.

 

 

The collapsing of the wave function , is surely one of quantum theory's intriguing mysteries. Namely why should an observation, or a measurement cause a change of performance ie wave to particle. Perhaps if we embrace the fact that it happens, can lead to an idea of what is going on in part .

 

A bird is flying fine free in the sky. Now lets grab it and examine it to see how its flying. The act of grabbing it causes it to stop flying. Maybe waves are good if they are left alone to wave and do their business. If we or other matter get too much of a hold, then the waves have no option but to respond by taking on a particle form. Maybe this is necessary for matter to interact with waves. To change state from probability to reality. Sort of like those parallel miniature setting switches ( 8 bit switches ) [ on off on on off off on off]. Once set the switches are encoded until the system is reset [ 00000000 ]. The universe is quietly going from a probability state to a Reality state. Past to Future.

Edited April 10, 2011 by Mike Smith Cosmos

[foszae]

A bird is flying fine free in the sky. Now lets grab it and examine it to see how its flying. The act of grabbing it causes it to stop flying. Maybe waves are good if they are left alone to wave and do their business. If we or other matter get too much of a hold, then the waves have no option but to respond by taking on a particle form. Maybe this is necessary for matter to interact with waves. To change state from probability to reality. Sort of like those parallel miniature setting switches ( 8 bit switches ) [ on off on on off off on off]. Once set the switches are encoded until the system is reset [ 00000000 ]. The universe is quietly going from a probability state to a Reality state. Past to Future.

 

the shift from probability to reality is precisely the important detail regarding wave function collapse. but i'll skip the math. the 'mystery' of wave forms is a matter of scale. what you're talking about suddenly is that there are patterns existing solely in sub-dimensions. there are events occuring in quantum levels which do not produce any observable evidence in the mechanical world. that does not mean they don't exist, by any means. it's simply that we can't tell what is about to happen until we see the results decay to a state where it overlaps our D4 world. when we're talking about a wave, it's a theoretical placeholder, suggesting that there is an energy which interacts previous to our world, and that we are merely positing that there is something going on there.

 

it's somewhat like this. we imagine a wave of potentiality occuring in dimension 5. there is a similar though different potential in dimension 6. the fact that those dimensions overlap means that the two separate potentials can harmonize or interfere with each other (as frequency waves do). the product of those waves interacting then specifically is bumped up so that it is overlapping with D4 Time. but it's not overlapping in the same way, because once it has reached that point, it is suddenly subjected to the rules of mechanical/nuclear physics, stripping it of its ability to continue interacting as untapped potential in lower-order dimensions. the 'collapse' then is the breakdown of deeper interactions as they 'fail out' into the real world we already know.

[bombus]

Schrodinger's Hat - re: many worlds interpretation. My question is who or what chooses which universe YOU end up being in?