Quantum mechanics contradicts with the experiment result of light speed

[Jeremy0922]

According with Quantum Mechanics, the electron is moving in the potential field V( r ) produced by proton in a hydrogen atom, and r is the distance of the electron to the proton. At any time, only if the propagation speed of potential field V( r ) by the proton is infinite, the potential field acting on the electron could be expressed by V( r ). Clearly, that contradicts with the experimental result of propagation speed of electromagnetic field (light), as well known, the speed of light in the vacuum is finite, and is about 300,000Km/s.

 

So, I think quantum mechanics contradicts with the experiment result of light speed, is that right?

[ajb]

So, I think quantum mechanics contradicts with the experiment result of light speed, is that right?

 

I would not be surprised as quantum mechanics is not a relativistic theory. In particular, the theory is treated as electrostatics.

 

You need to consider quantum electrodynamics.

[Jeremy0922]

I would not be surprised as quantum mechanics is not a relativistic theory. In particular, the theory is treated as electrostatics.

 

You need to consider quantum electrodynamics.

 

This question imply that

the potential field acting on the electron is not V ( r ), but is V ( X ) caused by the proton at previous position and previous time t'. V ( X ) is difficult to be determined, because the previous position could not be determined by unpredictable motion of particle according to QM conception.

I think that is a serious problem that the electron is moving in a potential field undetermined, and the potential function V( X ) in the Schrödinger equation of the electron can not be determined.

[mississippichem]

This question imply that

the potential field acting on the electron is not V ( r ), but is V ( X ) caused by the proton at previous position and previous time t'. V ( X ) is difficult to be determined, because the previous position could not be determined by unpredictable motion of particle according to QM conception.

I think that is a serious problem that the electron is moving in a potential field undetermined, and the potential function V( X ) in the Schrödinger equation of the electron can not be determined.

 

As ajb stated, you need to consider quantum electrodynamics. The standard non-relativistic treatment of atoms and molecules evokes the Born-Oppenheimer approximation where the nuclear motion is said to be on such a different time scale than motion of the electrons that they can be "held motionless" when solving the eigenvalue equations for the energies of the electrons. If you are working on a many electron system you can use variational methods to solve an optimization problem minimizing the coefficients of the basis states for the wavefunction in the time independent potential of the nuclei. This is actually a very good approximation for many atomic and molecular systems. IIRC it starts to fall apart for large nuclei where spin-orbit coupling and relativistic contraction of orbitals become non-negligible. As previously stated QED can be used for greater accuracy but I really only have a rudimentary understanding of such things and they are largely above my pay grade so I'll leave that to someone more qualified.

[EquisDeXD]

According with Quantum Mechanics, the electron is moving in the potential field V( r ) produced by proton in a hydrogen atom, and r is the distance of the electron to the proton. At any time, only if the propagation speed of potential field V( r ) by the proton is infinite, the potential field acting on the electron could be expressed by V( r ). Clearly, that contradicts with the experimental result of propagation speed of electromagnetic field (light), as well known, the speed of light in the vacuum is finite, and is about 300,000Km/s.

 

So, I think quantum mechanics contradicts with the experiment result of light speed, is that right?

 

Your really not saying anything more than "Something that exists in a field acts accordingly". The virtual photons don't propagate within the field that's already existing, they in a way already exist at the place in a field where they interact within a field which is where time symmetry arises from, which I think in relativistic terms can be described as a static electro-magnetic field or a time frame independent field. When there's a specific "change", that change happens at the speed of light, but when it's just a field just sitting there, it's existence of the interaction, a field doesn't propagate to where it already exists. I could be mis-interpreting you, but I hope I'm understanding the question well enough.

Edited October 16, 2012 by EquisDeXD

[Jeremy0922]

As ajb stated, you need to consider quantum electrodynamics. The standard non-relativistic treatment of atoms and molecules evokes the Born-Oppenheimer approximation where the nuclear motion is said to be on such a different time scale than motion of the electrons that they can be "held motionless" when solving the eigenvalue equations for the energies of the electrons. If you are working on a many electron system you can use variational methods to solve an optimization problem minimizing the coefficients of the basis states for the wavefunction in the time independent potential of the nuclei. This is actually a very good approximation for many atomic and molecular systems. IIRC it starts to fall apart for large nuclei where spin-orbit coupling and relativistic contraction of orbitals become non-negligible. As previously stated QED can be used for greater accuracy but I really only have a rudimentary understanding of such things and they are largely above my pay grade so I'll leave that to someone more qualified.

 

 

In a hydrogen atom, selecting the coordinate system of the proton (nucleus), the proton is at rest. Considering the motion of electron referring to the proton, we could solve the problems of hydrogen atomic structure, but the results must be modified to consider the effect of motion of the proton. The reduced mass of the electron replaces the mass of the electron, the results modified will be more accurate to experiment results.

That means the motion of the proton can not be ignored.

Then, we have to think what the motion of the proton is relative to? is the center-of-mass of the electron and the proton?

and why the effect of the proton's motion could be described by modification with the replacement of reduced mass of the electron?

 

Your really not saying anything more than "Something that exists in a field acts accordingly". The virtual photons don't propagate within the field that's already existing, they in a way already exist at the place in a field where they interact within a field which is where time symmetry arises from, which I think in relativistic terms can be described as a static electro-magnetic field or a time frame independent field. When there's a specific "change", that change happens at the speed of light, but when it's just a field just sitting there, it's existence of the interaction, a field doesn't propagate to where it already exists. I could be mis-interpreting you, but I hope I'm understanding the question well enough.

 

 

In a hydrogen atom, the electron is moving in the electric potential field caused by the moving proton. the potential function V( X ) in the Schrödinger equation of the electron could not be determined, if we consider the motion of the proton, because the V( X ) should be determined by the previous postion of the proton which is unpredictable.

[mississippichem]

In a hydrogen atom, selecting the coordinate system of the proton (nucleus), the proton is at rest. Considering the motion of electron referring to the proton, we could solve the problems of hydrogen atomic structure, but the results must be modified to consider the effect of motion of the proton. The reduced mass of the electron replaces the mass of the electron, the results modified will be more accurate to experiment results.

That means the motion of the proton can not be ignored.

Then, we have to think what the motion of the proton is relative to? is the center-of-mass of the electron and the proton?

and why the effect of the proton's motion could be described by modification with the replacement of reduced mass of the electron?

 

Bold mine

 

I actually agree with you up until the part where you say we "can not ignore" the motion of the proton. Think about the proton mass versus the electron mass.

 

The motion of the proton can be ignored, and is, daily by people working in the relevant fields. If you've ever tried to solve the coupled Schrodinger equations for the electronic and nuclear motion simultaneously you would know that they are quite nightmarish. That full Hamiltonian is often not diagonalizable and you have to resort to numerical methods that may or may not be stable.

 

I understand what you are saying: not accounting for the motion of the nucleus leads to some inaccuracy in the solutions for the electron energy levels. I'm just trying to say that the approximation of not considering the nuclear motion is not as bad as you think and actually provides tenable results for many applications. I realize that there are situations in which this approximation becomes much less valid as I stated above.

 

As far as your comment concerning the reduced mass, yes I've seen people stick the reduced mass for the electrons+nuclei into the constant the term scaling the kinetic energy operator in the Hamiltonian.

 

You should read the "derivation" section in the wikipedia article for the Born Oppenheimer approximation.

 

Wikipedia: Born Oppenheimer Approximation

 

Be warned that though the derivation is fully non-relativistic, it is fairly hard-nose and might take some time to understand. I'll be glad to assist if you need some assistance. This is one of those exercises everyone should do once and never again . It's kind of like learning to write down the Laplacian in spherical polar coordinates from scratch, tedious and hairy but instructive.

[EquisDeXD]

In a hydrogen atom, the electron is moving in the electric potential field caused by the moving proton. the potential function V( X ) in the Schrödinger equation of the electron could not be determined, if we consider the motion of the proton, because the V( X ) should be determined by the previous postion of the proton which is unpredictable.

 

In quantum physics you have to be careful about classical analogies. Just because there is a mathematical property called "spin" doesn't mean quantum particles are actually spinning, it just refers to how the wave mechanics propagates, either clockwise or counterclockwise. In a stationary atom, you don't know the particle is actually "moving", all you can do is have an idea of it's momentum, or its position, and if you exactly measure it's position, then you don't know it's momentum. Particles like electrons don't physically move or "accelerate" around the nucleus through any physical motion, it would have to radiate its energy away to do so. Your use of what seems to be the uncertainty principal seems to be fine, but there's not many classical aspects you can put into the particle realm. In quantum mechanics, the electron isn't "moving" around the nucleus, it just "is" around the nucleus, which is where quantum field theory comes in.

Edited October 17, 2012 by EquisDeXD

[Jeremy0922]

Bold mine

 

I actually agree with you up until the part where you say we "can not ignore" the motion of the proton. Think about the proton mass versus the electron mass.

 

The motion of the proton can be ignored, and is, daily by people working in the relevant fields. If you've ever tried to solve the coupled Schrodinger equations for the electronic and nuclear motion simultaneously you would know that they are quite nightmarish. That full Hamiltonian is often not diagonalizable and you have to resort to numerical methods that may or may not be stable.

 

I understand what you are saying: not accounting for the motion of the nucleus leads to some inaccuracy in the solutions for the electron energy levels. I'm just trying to say that the approximation of not considering the nuclear motion is not as bad as you think and actually provides tenable results for many applications. I realize that there are situations in which this approximation becomes much less valid as I stated above.

 

As far as your comment concerning the reduced mass, yes I've seen people stick the reduced mass for the electrons+nuclei into the constant the term scaling the kinetic energy operator in the Hamiltonian.

 

You should read the "derivation" section in the wikipedia article for the Born Oppenheimer approximation.

 

Wikipedia: Born Oppenheimer Approximation

 

Be warned that though the derivation is fully non-relativistic, it is fairly hard-nose and might take some time to understand. I'll be glad to assist if you need some assistance. This is one of those exercises everyone should do once and never again . It's kind of like learning to write down the Laplacian in spherical polar coordinates from scratch, tedious and hairy but instructive.

 

 

Thank you give me many good references to understand the mathematical approximation to treat QM problems.

As J. Slater said "Schrodinger equation provides the precise mathematical foundation for many problems of atomic, molecular, and solid-state structure....", I don't try to deney his viewpoint. I believe Born Oppenheimer approximation is an effective mathematical tool for treatment of some complex QM problems, but it will arise some serious problems to interpret the hydrogen atomic model by means of the unpredictable motion of particle, including the problems above.

So, I have to think matter wave maybe a wrong conception, and Schrodinger equation could not depend on it.

 

In quantum physics you have to be careful about classical analogies. Just because there is a mathematical property called "spin" doesn't mean quantum particles are actually spinning, it just refers to how the wave mechanics propagates, either clockwise or counterclockwise. In a stationary atom, you don't know the particle is actually "moving", all you can do is have an idea of it's momentum, or its position, and if you exactly measure it's position, then you don't know it's momentum. Particles like electrons don't physically move or "accelerate" around the nucleus through any physical motion, it would have to radiate its energy away to do so. Your use of what seems to be the uncertainty principal seems to be fine, but there's not many classical aspects you can put into the particle realm. In quantum mechanics, the electron isn't "moving" around the nucleus, it just "is" around the nucleus, which is where quantum field theory comes in.

 

Thank you, but I think the hydrogen atomic structure and spectrum are the typical questions of QM.

Edited October 18, 2012 by Jeremy0922

[EquisDeXD]

Thank you, but I think the hydrogen atomic structure and spectrum are the typical questions of QM.

 

But an electron doesn't actually "move" between quantum states either, it just appears or "correlates" to another energy state.

[Jeremy0922]

But an electron doesn't actually "move" between quantum states either, it just appears or "correlates" to another energy state.

 

 

In a hydrogen atom, the electron is moving really with an energy level (or state ), and the motion of the electron is unpredictable and described by wave function by means of QM conception.

[EquisDeXD]

In a hydrogen atom, the electron is moving really with an energy level (or state ), and the motion of the electron is unpredictable and described by wave function by means of QM conception.

 

There's no physical acceleration, only oscillation patterns and fields. By current quantum mechanics, an electron must transfer between quantum states without physically moving through the intervening volume of space because otherwise that would create analogous amounts of energy that would cause destructive interference between the electron's oscillation and the electron would stop existing.

Edited October 18, 2012 by EquisDeXD

[swansont]

In a hydrogen atom, the electron is moving really with an energy level (or state ), and the motion of the electron is unpredictable and described by wave function by means of QM conception.

Well, no. QM abandons the notion of classical trajectories, so you really can't talk about the motion of the electron. The expectation value of the momentum is zero for an electron in the 1S state.

[Jeremy0922]

Well, no. QM abandons the notion of classical trajectories, so you really can't talk about the motion of the electron. The expectation value of the momentum is zero for an electron in the 1S state.

 

 

The electron is at different place at different time, isn't it?

[EquisDeXD]

The electron is at different place at different time, isn't it?

 

The electron is, but it didn't have to travel through the intervening space to do it, which means no movement or acceleration.

Edited October 19, 2012 by EquisDeXD

[Jeremy0922]

<br />The electron is, but it didn't have to travel through the intervening space to do it, which means no movement or acceleration.<br />

<br /><br /><br />

And the proton is also at different place at different time, so they are moving in hydrogen atom.

The electron is at the electric field produced by the proton at previous time, because propagation velosity of the electric field is finite c.

[EquisDeXD]

<br /><br /><br />

And the proton is also at different place at different time, so they are moving in hydrogen atom.

The electron is at the electric field produced by the proton at previous time, because propagation velosity of the electric field is finite c.

Propagation only applies when there's a change over a region of space. The electro-magnetic field of a proton already exists to where it's previous virtual photons propagated too. The large factor of this is uncertainty. While a change in a field propagates at c, the field always has the uncertainty which essentially allows it to constantly exist where it already had the uncertainty of existing.

Edited October 19, 2012 by EquisDeXD

[Jeremy0922]

Propagation only applies when there's a change over a region of space. The electro-magnetic field of a proton already exists to where it's previous virtual photons propagated too. The large factor of this is uncertainty. While a change in a field propagates at c, the field always has the uncertainty which essentially allows it to constantly exist where it already had the uncertainty of existing.

 

 

Does the magnitude of EMF you said relates to the position?

[swansont]

The electron is at different place at different time, isn't it?

Only if you have measure its location. As EquisDeXD has also pointed out, there is no defined trajectory between measurements. You can't impose classical physics on this and expect valid results.

 

Current QM is wrong, obviously, of course there is physical acceleration. When an electron is orbiting nucleus, small disturbances won't count. When electron comes back to S1, it causes photon to emit. That photon takes the most disturbing energy away from electron and harmonic wave emerges again.

!

Moderator Note

This has been split to a new thread, rather than sidetracking this one

http://www.scienceforums.net/topic/69862-qm-is-wrong/

[Nobrainer]

Your really not saying anything more than "Something that exists in a field acts accordingly". The virtual photons don't propagate within the field that's already existing, they in a way already exist at the place in a field where they interact within a field which is where time symmetry arises from, which I think in relativistic terms can be described as a static electro-magnetic field or a time frame independent field. When there's a specific "change", that change happens at the speed of light, but when it's just a field just sitting there, it's existence of the interaction, a field doesn't propagate to where it already exists. I could be mis-interpreting you, but I hope I'm understanding the question well enough.

A field does propagate to where it already exists or light waves could not travel after the first photon started

[ajb]

As EquisDeXD has also pointed out, there is no defined trajectory between measurements.

 

Indeed, and this always makes me scratch my head!

 

Roughly, quantum mechanics tells you about what to expect when you make a measurement, but nothing about what happens when "you are not looking"!

[EquisDeXD]

A field does propagate to where it already exists or light waves could not travel after the first photon started

They don't need to travel when their uncertainty already covers the area within the field. Because their uncertainty extends to such, they can interact with anything within a field, thus making their effects real.

Indeed, and this always makes me scratch my head!

 

Roughly, quantum mechanics tells you about what to expect when you make a measurement, but nothing about what happens when "you are not looking"!

 

Well it doesn't directly say, but there's still mathematical evidence for what happens, like superposition, and the fact that we can only see the specific statistical results we see as an effect of specific mechanics, such as wave mechanics. Otherwise the transition between states can happen with no trajectory because the electron doesn't move, at the moment it's quantum state changes, it's probability therefore instantaneously correlates to new probabilities, and correlation is not a time dependent phenomena.

Edited October 20, 2012 by EquisDeXD

[Jeremy0922]

Only if you have measure its location. As EquisDeXD has also pointed out, there is no defined trajectory between measurements. You can't impose classical physics on this and expect valid results.

 

 

 

 

Whether or not it can be measured, the position of the particle is a fundamental physical quantity for the physical theories including QM to describe the phenomenon. For example, the potential V( X ) of the electron in hydrogen atom need known the precise positions of the proton and the electron for its Schrodinger equation.

 

Indeed, and this always makes me scratch my head!

 

Roughly, quantum mechanics tells you about what to expect when you make a measurement, but nothing about what happens when "you are not looking"!

 

 

If we consider the Schrodinger equation as a resonant equation of hydrogen atomic structure, many contradictions caused by matter wave could be avoided.

[EquisDeXD]

Whether or not it can be measured, the position of the particle is a fundamental physical quantity for the physical theories including QM to describe the phenomenon. For example, the potential V( X ) of the electron in hydrogen atom need known the precise positions of the proton and the electron for its Schrodinger equation.

We do experiments and gather statistical data that can only be described under specific sets of mechanics, and those mechanics say there is no physical motion between states. Also, in QM you don't always need to know precise position or precise momentum, you can mix and math to get an accurate probability model which allows you to see more or less where an electron exists most away from the nucleus.

 

 

 

 

If we consider the Schrodinger equation as a resonant equation of hydrogen atomic structure, many contradictions caused by matter wave could be avoided.

 

Quantum mechanics often does use wave mechanics to describe probability, but there still isn't exactly a physical oscillation, which is why you need quantum field theory to describe the actual existence of particles as merely fields which can have mathematical oscillation patterns.

Edited October 20, 2012 by EquisDeXD

[Jeremy0922]

We do experiments and gather statistical data that can only be described under specific sets of mechanics, and those mechanics say there is no physical motion between states. Also, in QM you don't always need to know precise position or precise momentum, you can mix and math to get an accurate probability model which allows you to see more or less where an electron exists most away from the nucleus.

 

Quantum mechanics often does use wave mechanics to describe probability, but there still isn't exactly a physical oscillation, which is why you need quantum field theory to describe the actual existence of particles as merely fields which can have mathematical oscillation patterns.

 

 

We are discussing the behaviours of the electron and the proton in the hydrogen atom, and motion of them is Essential features that we can confirm.

 

Probability is an interpretation by matter wave, But meet many difficulties that can not be explained.

 

So, I think we have to select an other way to understand Schrodinger equation.