Heisenberg principle

[chandragupta]

Do superpositions represent all the theoretically possible positions or states or conditions of a quantum but only one of them truly actualizes or materializes when observer finally observes or measures the quantum I.e. or opens the Box containing the SCHRODINGER'S CAT in order to check whether the cat is dead or alive?

[Mike Smith Cosmos]

Do superpositions represent all the theoretically possible positions or states or conditions of a quantum but only one of them truly actualizes or materializes when observer finally observes or measures the quantum I.e. or opens the Box containing the SCHRODINGER'S CAT in order to check whether the cat is dead or alive?

 

As I understand it, that is how I believe things happen . However I must say my conclusions are only drawn from much reading around the subject from 1800 to 2012 ( not meaning that I have been alive for 212 years) but the big men of this side of science have lived, thought , experimented and proposed their ideas , during this period to bring our understanding to the present State. Many of these men have warned that Quantum Physics is strange, and are still warning, so as far as i am concerned the field of investigation is still wide open , and getting bigger all the time. The problem is the whole thing is either so blinking small or requires so much blinking energy that the likes of individuals can no longer do experiments like Edison with light bulbs on a table top but need Large Hadron Colliders needing ££££££££££££££££. ETc.

[chandragupta]

1352551871[/url]' post='712622']

As I understand it, that is how I believe things happen . However I must say my conclusions are only drawn from much reading around the subject from 1800 to 2012 ( not meaning that I have been alive for 212 years) but the big men of this side of science have lived, thought , experimented and proposed their ideas , during this period to bring our understanding to the present State. Many of these men have warned that Quantum Physics is strange, and are still warning, so as far as i am concerned the field of investigation is still wide open , and getting bigger all the time. The problem is the whole thing is either so blinking small or requires so much blinking energy that the likes of individuals can no longer do experiments like Edison with light bulbs on a table top but need Large Hadron Colliders needing ££££££££££££££££. ETc.

 

Thanks. Now I have found a kindred soul to explore this beautiful but extremely strange world of quanta in a common sensical way. Thanks once again!

[Mike Smith Cosmos]

Thanks. Now I have found a kindred soul to explore this beautiful but extremely strange world of quanta in a common sensical way. Thanks once again!

 

De Nada Portugese ( no matter ) or Prego Italian ( ok. No Problemo ) Neither of which are spelled correctly. ( scientist never can spell ! ) .

 

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[LaurieAG]

It's a matter of convenience, in the context of whether the equation has factors of 2*pi in it or not. e.g. Schrödinger's equation does. It's similar to whether you use Planck's constant or the reduced Planck's constant. [math]\hbar\omega[/math] vs. [math]h\nu[/math]

 

And as a result of that convenience, especially when rotating sources are considered in dark matter calculations, it appears that the speed of the electrons are being increased (and therefore giving an artificial increase in relative mass) instead of regarding the sources rotation speed as being increased with the rest mass remaining constant as well as the photon stream emitting from that mass.

 

You will always capture the same amount of light from a rotating source during a fixed period of observation whether the source is rotating at x, 2x, 3x etc. This is where our observation point is and this is where the quantum calculations should come back full circle, out of necessity not convenience.

[Mike Smith Cosmos]

Thanks. Now I have found a kindred soul to explore this beautiful but extremely strange world of quanta in a common sensical way. Thanks once again!

 

I have been thinking on these matters over the last few days, and I am relentlessly drawn back to the area or the threshold of many of these quantum happenings. It would appear unless I am mistaken that the symbolic LID of the box that Schroenigers cat lurks within , lies just outside the outer shell of electrons of an atom. All be it that the outer shell is no more than a high energy band, one would suspect that this must have some form of proximity to the atom in question. So close,and yet we can still be happy we are outside the box and the cat is quite ok being potentially in both states within the box. The difficulty arises when we open the lid, where we trigger a series of happenings that seem to obey the strange quantum happenings that stretch our brains of classical logic. Here the mathematicians step in and come up with a set of equations that work , but are very hard to visualize and understand in real life images. ( So I am told ) . Lets keep the lid closed for a moment. I don't like to be kept out of the 'picture' with my metaphor type brain , so I still try to at least think of myself ( not literally ) but non-the-less as being in some form of wonderland where strange quantum things happen ( like Alice in wonderland , quantum Alice that is in side the atom). I have been told that special relativity , will enable this transition. However , as far as I can see, that is still viewing inside the atom , relative to an observer outside the atom. If we are inside , figuratively of course , we are not observing from outside. So what do we see, or feel, by being inside ........Floating about in the quantum world inside the territory of the atom ? ............

 

How are you so far ....?

 

 

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Edited November 13, 2012 by Mike Smith Cosmos

[Mike Smith Cosmos]

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. Now there's a thing ! What is it like if we are inside the atom but not a real observer in the normal sense of the word , but an Alice in quantum world observer. Thus fooling the Box and not really opening the lid. ?

 

 

What do we see ? Wow ee !

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Edited December 4, 2012 by Mike Smith Cosmos

[Mike Smith Cosmos]

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Do we " see " as some ( not me ) have suggested, only one single electron (in the entire universe) in all possible and acceptable positions in the universe . Obeying the Pauli exclusion principle. The wave function not having collapsed because we are not a real observer ( but an Alice in quantumland observer ) . All at the same " time " ( What time ? ). Or at a succession of different times ( But what different times , a trillionth of a second, or a 10 to the minus 43 trillionths of a second later. ). Or just all sitting there as it were frozen in time just sitting with a probability to "be " or come into existence ? Or not in the entire universe, but only for this particular atom?

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Edited December 4, 2012 by Mike Smith Cosmos

[juanrga]

Should the [current] inability to "measure" position and momentum mean that a particle at a moment in time does not have a given position and speed?

 

Quantum mechanics says that the particle cannot have both a position and a momentum (speed), with independence of our measurements.

 

A quantum object has a given property when its wavefunction is an eigenfunction of the quantum operator corresponding to that property. Quantum mechanics says that there is not wavefunction that can be eigenfunction of both position and momentum operators and therefore no quantum object can have both a position and a momentum (speed). This is the reason why wavefunctions are either functions of position [math]\Psi(x,t)[/math] or functions of momentum [math]\Psi(p,t)[/math] but not of both.

 

Note: Nonrelativistically the momentum p is given by p=mv where v is the velocity and m the mass.

Edited December 7, 2012 by juanrga

[Mike Smith Cosmos]

Juanrga.

 

Does that mean, by what you say, that the particle actually does Not intrinsically posses both position and momentum, or that we can not measure, utilize or observe both position and momentum at the same time ?

[juanrga]

Juanrga.

 

Does that mean, by what you say, that the particle actually does Not intrinsically posses both position and momentum, or that we can not measure, utilize or observe both position and momentum at the same time ?

 

It means that the quantum particle cannot be in a quantum state [math]\Psi[/math] with both a given position and a given momentum. If the particle cannot be in that state, then you cannot measure/observe the particle in that state. Next is the best funny explanation of what happens when someone violates the principle

 

[Mike Smith Cosmos]

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I gather from your amusing cartoon that " observe at your own peril " if trying to buck the ' momentum - position ' puzzle !

 

.Very good

Edited December 17, 2012 by Mike Smith Cosmos

[MigL]

No. It means separating position and momentum at the quantum level is IMPOSSIBLE. As evidenced by the ( impossible ) unicorn impaling the observer.

[Mike Smith Cosmos]

Then that must tell us something about the reality, or nature of a " particle" at the quantum level.. If it cannot have BOTH momentum and position , then its not a particle as our language infers. We should perhaps try to generate a new description of these entities. !

 

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I know we talk of wave -particle duality, but we find that hard to ',dare I say it ' visualize.

 

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( A wobblical entity ? ) or ( A bloblical entity ? )

 

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Like the Scarlet Pimpernel " You see me here , you see me there .............. ".....

Edited December 18, 2012 by Mike Smith Cosmos

[juanrga]

Then that must tell us something about the reality, or nature of a " particle" at the quantum level.. If it cannot have BOTH momentum and position , then its not a particle as our language infers. We should perhaps try to generate a new description of these entities. !

 

Who said you that the concept of particle implies having both a position and a momentum? A Newtonian particle must have both, but a quantum particle does not. In quantum mechanics, and in particle physics, a particle is not defined as a little sphere with both a position and a momentum.

 

If you do not like the term "particle" you can change the name and use "XAXFDBGTRJHGN" or anything of your invention, but the physics remain and maintain in mind that we scientist use the term particle:

 

everything in the universe is found to be made from twelve basic building blocks called fundamental particles, governed by four fundamental forces.

[Mike Smith Cosmos]

Juanrga

 

 

Yes , that is all very well, but surely if we find that the descriptor is misleading and confusing, is there not a case for moving on slightly to ease the way for clarity of thought, particularly for those approaching physics and stumbling with all this mystery around quantum behaviour.

 

Perhaps you are saying that above all else the atomic particles are PARTICLES first and foremost. ? But with all the FIELD science,; electric, magnetic, Electro-magnetic, quantum field, Higgs Field, etc etc is there not a case to view things more in that field direction say, or some other image , than the particle direction. I am not making a big issue about it, We just seem to be more and more and more particles and then trying to unify them all in the standard model. I would not dare for one moment to suggest the standard model is in any way wrong, BUT perhaps viewing from a field direction, which I am aware String theory is well and truly in that direction,, but they appear to have gone to infinity and back.

 

Surely there must be some happy medium where we can understand what is happening at the quantum level , other than going into some Mathematical Nervanaland. No ?

 

You are going to hit me with Maths now. !

 

.Yes the standard model is gaining beauty by the day, but in your link to Cern it still shows the particle as a round ball , surely we need to get off this image IF as you and I know is probably incorrect. ( I' ll probably be struck down ). It probably looks more like a spinning probability wave function.

Edited December 18, 2012 by Mike Smith Cosmos

[O'Nero Samuel]

Are we not digressing from the truth with this nuance in the position and momentum of the EUP? I believe that it was talking about measurement. That one cannot measure to great precision simultaneously the position and momentum of a quantum particle. This, I believe, does not imply that they do not possess both at every instance, but that you cannot measure to a high degree of accuracy and simultaneously both quantities of a quantum particle.

Not having position and momentum, and measurement of position and momentum are two different phenomenon and misunderstanding this could lead to great doldrums. Like the above cartoon, if you think to focus your attention on momentum, you loose accuracy in measuring its position, and vice versa.

[Mike Smith Cosmos]

Are we not digressing from the truth with this nuance in the position and momentum of the EUP? I believe that it was talking about measurement. That one cannot measure to great precision simultaneously the position and momentum of a quantum particle. This, I believe, does not imply that they do not possess both at every instance, but that you cannot measure to a high degree of accuracy and simultaneously both quantities of a quantum particle.

Not having position and momentum, and measurement of position and momentum are two different phenomenon and misunderstanding this could lead to great doldrums. Like the above cartoon, if you think to focus your attention on momentum, you loose accuracy in measuring its position, and vice versa.

.

 

I must admit I have read this several times as an explanation of the Heisenberg uncertainty principle. That a photon used to observe causes sufficient interaction so as to prevent precise measurements of both attributes. I have also read of mathematical explanations which utilise the plank constant as a limiting value against either momentum or position pushing one in one direction or the other ( towards position or momentum) . However our colleague Juanrga is saying, I think , not sure ( I might have missunderstood Juanrga ) that the particle does not possess both attributes at the same time. I have often wondered which is the correct explanation or indeed if either explanation is correct.?

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Edited December 18, 2012 by Mike Smith Cosmos

[juanrga]

Juanrga

 

 

Yes , that is all very well, but surely if we find that the descriptor is misleading and confusing, is there not a case for moving on slightly to ease the way for clarity of thought, particularly for those approaching physics and stumbling with all this mystery around quantum behaviour.

 

Perhaps you are saying that above all else the atomic particles are PARTICLES first and foremost. ? But with all the FIELD science,; electric, magnetic, Electro-magnetic, quantum field, Higgs Field, etc etc is there not a case to view things more in that field direction say, or some other image , than the particle direction.

 

As shown by Wheeler and Feynman all the effects usually attributed to electric fields, magnetic fields, electromagnetic fields can be explained using a theory of only particles. Quantum fields can be also eliminated

 

http://rmp.aps.org/abstract/RMP/v21/i3/p425_1

 

http://rmp.aps.org/abstract/RMP/v67/i1/p113_1

 

Surely there must be some happy medium where we can understand what is happening at the quantum level

 

We do not need to introduce a medium to understand what is happening. One of the first advances of modern physics was to eliminate the unobservable aether as medium for the electromagnetic waves (this was the born of the special theory of relativity). We would not gain anything by introducing some other unobservable medium.

 

Yes the standard model is gaining beauty by the day, but in your link to Cern it still shows the particle as a round ball , surely we need to get off this image IF as you and I know is probably incorrect. ( I' ll probably be struck down ). It probably looks more like a spinning probability wave function.

 

Yes, the CERN link has an artistic header image. But in no part of the text the webpage says that particles are round balls with colorful labels.

 

No, a quantum particle does not look as "a spinning probability wavefunction". A wavefunction is an abstract function which is not even defined in the ordinary space. The state of a particle is given by a wavefunction only in some special cases (free particle in a pure state) and only in some formulations of QM. Finally the concept of spin in quantum mechanics is not the classical concept of spinning around an axis.

 

 

Are we not digressing from the truth with this nuance in the position and momentum of the EUP? I believe that it was talking about measurement. That one cannot measure to great precision simultaneously the position and momentum of a quantum particle. This, I believe, does not imply that they do not possess both at every instance, but that you cannot measure to a high degree of accuracy and simultaneously both quantities of a quantum particle.

Not having position and momentum, and measurement of position and momentum are two different phenomenon and misunderstanding this could lead to great doldrums. Like the above cartoon, if you think to focus your attention on momentum, you loose accuracy in measuring its position, and vice versa.

 

Quantum mechanics is very clear at this point. It says that a quantum particle cannot be in a state [math]|\Psi\rangle[/math] with a well-defined value (eigenvalue) of both position and momentum. Either the particle is in a position eigenstate [math]|x\rangle[/math] and has a well-defined position, or in a momentum eigenstate [math]|p\rangle[/math] and has a well-defined momentum, but not both because position and momentum are non-commuting observables in QM.

 

You cannot measure what does not exist: a corollary of the above QM restriction is that you cannot measure the position and momentum of a quantum particle.

Edited December 19, 2012 by juanrga

[O'Nero Samuel]

Quantum mechanics is very clear at this point. It says that a quantum particle cannot be in a state [math]|\Psi\rangle[/math] with a well-defined value (eigenvalue) of both position and momentum. Either the particle is in a position eigenstate [math]|x\rangle[/math] and has a well-defined position, or in a momentum eigenstate [math]|p\rangle[/math] and has a well-defined momentum, but not both because position and momentum are non-commuting observables in QM.

 

No. I believe this your interpretation is wrong. What EUP was talking about was in measurement an not eigen state. When measuring the state of a quantum particle, there is a trade off in precision in measurement of its position and momentum. The range is the planks constant: this is analogous to the string used in the above cartoon; but it is really about measurement.

[Mike Smith Cosmos]

 

Yes, the CERN link has an artistic header image. But in no part of the text the webpage says that particles are round balls with colorful labels.

 

No, a quantum particle does not look as "a spinning probability wavefunction". A wavefunction is an abstract function which is not even defined in the ordinary space. The state of a particle is given by a wavefunction only in some special cases (free particle in a pure state) and only in some formulations of QM. Finally the concept of spin in quantum mechanics is not the classical concept of spinning around an axis.

 

 

When you say the word Quantum Particle What image comes into your mind then ? If not a round ball with the standard model Rows and columns of such particles.

 

Do you see a number of laws and Math equations Say Schroenigers equation, Etc Etc.

If so what do you see them housed in ? what does it look like ? a nano something or other ? Some superstring topography, ? Where and how are the laws and maths formulae stored ? What do you see in your Head ?

 

Surely there is some form of bedrock conglomerate that contains in some way the rules, laws and formulae if only in some form of influencing device ? If not where is it held ?

Edited December 20, 2012 by Mike Smith Cosmos

[MigL]

What is EUP Samuel ?

 

Juanarga is absolutely correct. Position and momentum of a quantum particle CANNOT be known to arbitrary accuracy because its IMPOSSIBLE for a quantum particle to possess an arbitrarily accurate position and momentum. This is NOT an interpretation.

The HUP or inequality is derived from first principles ( mathematically not through observation or measurement ) in 3rd year university QM class of a Physics program here in Canada. And I believe Juan's degree is more advanced than 4yr, maybe PhD ?

 

 

And Mike why do you assume that you should be able to picture a quantum particle ? Is there anything in your everyday experiences that you can compare it to ? Should you also be able to picture 4d space-time of SR and GR ? Or the 10, 11 or 26 dimensions of string theory ? What do point particles look like, after all, an electron cannot have a volume or it would be 'made out of something' and, therefore, would not be fundamental ( to say nothing about charge 'distribution' ).

Edited December 20, 2012 by MigL

[Mike Smith Cosmos]

 

And Mike why do you assume that you should be able to picture a quantum particle ? Is there anything in your everyday experiences that you can compare it to ? Should you also be able to picture 4d space-time of SR and GR ? Or the 10, 11 or 26 dimensions of string theory ? What do point particles look like, after all, an electron cannot have a volume or it would be 'made out of something' and, therefore, would not be fundamental ( to say nothing about charge 'distribution' ).

 

I don't get it. Whats wrong with trying to visualise something as fundamental as an ELECTRON

 

Yes describe it in a Textbook full of whatever . But it obviously IS something , even if it is a charge point or bubble floating in a complex universal field !

 

By all means say "nobody knows !" But at least we could start looking , trying to visualise it. We have a very sophistocated brain which can comprehend great pros, poetry, art , and a whole host of abstract ideas. Whats wrong with trying to visualise the electron. The very vehicle of our modern world...

[Delta1212]

 

I don't get it. Whats wrong with trying to visualise something as fundamental as an ELECTRON

 

Yes describe it in a Textbook full of whatever . But it obviously IS something , even if it is a charge point or bubble floating in a complex universal field !

 

By all means say "nobody knows !" But at least we could start looking , trying to visualise it. We have a very sophistocated brain which can comprehend great pros, poetry, art , and a whole host of abstract ideas. Whats wrong with trying to visualise the electron. The very vehicle of our modern world...

The problem is that our brains are very good at creating a particular conception of the universe, but that conception is heavily rooted in this narrow band of the universal scale. Our brains understand how things work at certain sizes, certain speeds, and certain energy levels, but when you venture outside those bounds, you start encountering things that our brains weren't really developed to intuit because they never had to deal with them in any meaningful way during the course of human history.

 

Imagine trying to describe a liquid to someone who has only ever encountered solids. You might draw an analogy with the way sand sort of flows, but if such a person attempts to imagine what the ocean looks like, they're going to wind up picturing a desert of semi-transparent blue sand. There's nothing in their experience that will allow them to picture the ocean as it actually is, only very rough approximations that will be very off in some respect.

 

And it's even worse trying to picture an electron because the very things we use to sense the world around us: light, vibration, temperature, etc, all behave differently on the scale of an electron. So it's like someone who has never seen liquids trying to imagine what an ocean would look like to a blind person.

 

There's nothing wrong with trying to do it, and it's philosophically interesting, but don't expect to come up with an answer that is both accurate and satisfying.

[Mike Smith Cosmos]

The problem is that our brains are very good at creating a particular conception of the universe, but that conception is heavily rooted in this narrow band of the universal scale. Our brains understand how things work at certain sizes, certain speeds, and certain energy levels, but when you venture outside those bounds, you start encountering things that our brains weren't really developed to intuit because they never had to deal with them in any meaningful way during the course of human history.

 

Imagine trying to describe a liquid to someone who has only ever encountered solids. You might draw an analogy with the way sand sort of flows, but if such a person attempts to imagine what the ocean looks like, they're going to wind up picturing a desert of semi-transparent blue sand. There's nothing in their experience that will allow them to picture the ocean as it actually is, only very rough approximations that will be very off in some respect.

 

And it's even worse trying to picture an electron because the very things we use to sense the world around us: light, vibration, temperature, etc, all behave differently on the scale of an electron. So it's like someone who has never seen liquids trying to imagine what an ocean would look like to a blind person.

 

There's nothing wrong with trying to do it, and it's philosophically interesting, but don't expect to come up with an answer that is both accurate and satisfying.

 

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I must say , I like your approach to this issue, as you have not totally dismissed the need I and believe me , many others have , to seek some way to visualize how things look and how they function. This of course, accepting that they ( the particles ) are going to look and behave radically different from everyday life. Perhaps you are willing to start the process off, imagining I am blind and have never seen the sea ( figuratively).

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Edited December 20, 2012 by Mike Smith Cosmos