Are electrons wave or a particle?

[jcsd]

De Broglie and Bohm's interpretation is treated as one as Bohm built on De Broglie's work and gave it a more rigourous framework, there are other realist theories that are simlair to Bohm's.

 

[pmb]

Originally posted by benzun_1999
dear reader,
i have a ineresting question. Are electrons waves or particle? Electrons act as a particle when electricity passes through a conductor and basically have studied electrons as a particle but according to quantum physics electrons are waves, if you do the two slit experiment with electrons the result will be that electrons are waves.

-benzun

If i am wrong please let me know.

The most accurate answer is that they are neither.

Pete

 

[elas]

Surely they are both, the particle is bound, the wave extends by influence, to infinity.

 

[tribdog]

Are electrons waves or particles?

answer #1: Yes
answer #2: Depends on if you're looking
answer #3: Why stop with electrons? photons, protons, neutrons, positrons, quarks, maybe even certain physicist's cats lead a life of duality. Maybe I do when I close my eyes and there's no one else around

 

[Albrecht]

Again, electrons - like all other elementary particles - are, according to de Broglie, particles. The particles are surrounded by waves which are caused by the field of the circling charges within the particle. These charges cause the force which keep the particle together.

The surrounding waves cause the interference field at a double slit and guide the particle through the slit. They give the impression that the particle is a wave.

If somebody knows an experiment which contradicts this description, please tell us. John Bell at least stated that he did not meet arguments against the presented model of a pilot wave.

Bohm is not a good reference for this question because he had a different goal. His primary goal was to find a deterministic wave function, it was not to resolve the particle wave problem.

 

[FZ+]

John Bell at least stated that he did not meet arguments against the presented model of a pilot wave.

John Bell did not conduct the experiments which violated the Bell inequalities, which he calculated to be required by any local realistic theory.

 

[Albrecht]

John Bell did not conduct the experiments which violated the Bell inequalities

Bell's inequalities concern entangled pairs of particles.

The pilot wave explanation for the particle-wave phenomenon has really nothing to do with this.

Of course Bell was aware of all experiments relevant for this case.

 

[ahrkron]

Originally posted by Albrecht
The particles are surrounded by waves which are caused by the field of the circling charges within the particle. These charges cause the force which keep the particle together.

"Circulating charges withing the particle"?
Not in mainstream physics.

"Elementary particles" are, by definition, the building blocks. They have no "circulating charges" within them.

The surrounding waves cause the interference field at a double slit and guide the particle through the slit.

Composite particles (like protons, neutrons, pions, etc.) do have components, but the electric field of such components should not be confused[/color] with the quantum-mechanical wave referred to by Schroedinger's equation.

Otherwise, non-composite particles (electrons, muons, taus, neutrinos and quarks) would not show a wave-like behavior, and they all do.

 

[jcsd]

Originally posted by Albrecht
Bell's inequalities concern entangled pairs of particles.

The pilot wave explanation for the particle-wave phenomenon has really nothing to do with this.

Of course Bell was aware of all experiments relevant for this case.

Bohm's explanation necessarily also ex[plain quantum entanglemnt if it is to be any use and infact papers on intepreting q. entanglment using the Bohmian model have been written.

The pilot wave doesn't violate Bell's inequality as it is a non-local hidden variables theory.

 

[christench]

The answer to the question is...'wave'
Classical physics occurs as an asymptotic limit in the 'wave' model.

But this is only a model. We are physicists. Our job is to model nature. The 'wave' has been defined by us. It is not reality.

I personaly have no idea about the true nature of the elctron, and I don't think anyone does. But I can calculate its energy levels given some simple potentials. I can write a computer program to compute energy in more complex potentials. But all I am doing is applying a model. And to do it I solve Schrodingers 'wave' equation.

Of course when we measure some property of the electron, we only ask classical questions of it, like what is its position or momentum? We don't measure the 'wave' function (although that might be possible, at least its magnitude) because it wouldn't mean much given our everyday experience of the world. No wonder then that we get classical 'particle' answers.

 

[elas]

The answer to the question is...'wave'

I have a collection of cuttings on electrons that include several images of electrons on their own and within an atom. These images are produced by various types of experiments.
If electrons consists only of a wave, and the wave exist only in model form; how are these images achieved?

 

[Albrecht]

Otherwise, non-composite particles (electrons, muons, taus, neutrinos and quarks) would not show a wave-like behavior, and they all do.

According to mainstream physics leptons and quarks are not composite. This was concluded from experiments:

In experiments it was tried to decompose such particles by bombarding them by high energy particles in an accelerator. They could not be decomposed even though the energy should have been sufficient.

The misunderstanding of the case comes from the assumption that the constituents of an elementary particle, which has mass, must also have mass. This, however, is an unnecessary and most probably wrong assumption. The constituents do have no mass, and in this case such particle can never be decomposed irrespective of the energy used.

From the Dirac function of the electron it follows that the "inside" of an electron orbits at the velocity of light c. The orbital frequency is the deBroglie frequency. This orbital motion causes the alternating field. This is not the electric field but the field descibed by the Schroedinger equation.

The electric charge on the other hand causes a magnetic field during this circulation. If this is computed by classical electrodynamics, the result is the true magnetic moment of the electron within a rel. accuracy of 0.001 .

By a similar calculation the constancy of the spin of any particle can be computed by classical means.

Isn't this a good prove that the electron is this way?

 

[christench]

I think I may have seen the same pictures of electrons, in crystals for example. These experiments are trying to image a wave. They set out to achieve it and use techniches that will get results. And they aparently work.

But don't we always measure what we are interested in for our model? I am certain you could find many pictures where the electron has acted like a particle, your monitor might be doing it now. You could devise an experiment to picture the electron as a particle. Sure enough you could get the result you want.

The way we design our experiments is determined by our model. If we model the electron as a wave we set out to observe the wave, or at least wave nature. If we model it as a particle, we ask particle questions in the experiment and get particle results.

In the end the model of an electron as a 'wave' is ALWAYS good, at least as far as our current experimental ability is concerned. Who knows, it may have to be modified in the future.

 

[Albrecht]

If we model the electron as a wave we set out to observe the wave, or at least wave nature. If we model it as a particle, we ask particle questions in the experiment and get particle results

This is an intelligent consideration. However, the situation seems to be much simpler. If you assume, like deBroglie did, that the electron is a real particle, this particle has an internal oscillation which causes the wave around it, you will not find an experiment, which contradicts this assumption.

Using this approach, you can calculate the particle parameters (like e.g. the magnetic momentum) in a classical way, in contrast to what you find in books of quantum mechanic; those books state that, in the assumption that the electron is a wave, the parameters (magn. moment, spin etc) can only be understood by QM. It is different!

If you like more details please look into http://www.ag-physics.org/electron

 

[christench]

If you like more details please look into http://www.ag-physics.org/electron

This is an interesting site, attempting to explain quantum mechanics in terms of classical mechanics. Of course this is always the aim because we only intuitively understand classical physics. Usually its left to semi-classical physicists. In semi-classical you can use classical trajectories, assuming non-classical ones interfere destructively, and give them a phase and then Bobs your uncle: Quantisation using classical laws of motion. At this website there is no attempt at quantisation. There is a hand waving argument at an explanation of spin quantisation, but it is not at all convincing.
Classical mechanics just cannot cover the spectrum of phenomena we can observe in quantum systems. There is a strong connection between the two extreems, one is just the limiting case of the other, and that's why you can compute parameters such as energy states of the hydrogen atom using largely classical equations (the Bohr atom) for example.

 

[Albrecht]

At this website there is no attempt at quantisation. There is a hand waving argument at an explanation of spin quantisation, but it is not at all convincing.

The quantization for the electron state in an atom was explained by Louis de Broglie in his famous paper
www.davis-inc.com/physics/broglie/broglie.shtml

His explanation is compatible with the model presented on the website referred above.

The constancy of the spin of all elementary particles (i.e. leptons and quarks) is proven classically using the assumption, that elementary particles oscillate internally with c. This was given by Paul Dirac in 1928 for the electron. It is assumed that this is true also for the other elem. particles.

It is true that the quantization of spin measurement, which is in fact the interaction of the electron's magnetic momentum with an external magnetic field, is not quantitatively explained. Only the mechanism which will most probably cause this, is explained. But, please keep in mind that quantum mechanics also does not explain this but only states the fact as existing by an appropriate formalism (as quantum mechanics never explain anything). So, maybe an incomplete explanation is better than no explanations at all (which is QM) because it shows the possible direction of the answer.

Classical mechanics just cannot cover the spectrum of phenomena we can observe in quantum systems.

christench: can you please give 1 or 2 more examples of this spectrum of phenomena?

 

[cmbezln]

Originally posted by benzun_1999
dear reader,
i have an interesting question. Are electrons waves or particle? Electrons act as a particle when electricity passes through a conductor but according to quantum physics electrons are waves, if you do the two slit experiment with electrons the result will be that electrons are waves.

-benzun

If i am wrong please let me know.

I've read some pretty compelling evidence that electrons only act as a particle when we view them with our eyes. When we are not, they act as wave existing throughout the universe at once. Even when electrons do posess qualities of a "particle", they only show "tendencies" to exist at best.

 

[Albrecht]

Even when electrons do posess qualities of a "particle", they only show "tendencies" to exist at best.

According to Louis de Broglie (Nobel price 1929) particles like the electron are real particles with a wave around. This wave around causes the interference phenomena and the quantization.

If you know any experiment, which is in conflict with this assumption, please let us know.

 

[selfAdjoint]

Read John Gribben's book "Schroedinger's Kittens" it's full of experiments showing the non-intuitive nature of the electron and photon.

And Bell's inequalities and the experiments, starting with Aspect's, that confirmed them knock simple hidden variable theories on the head. That would include deBroglie's. Bohm's modification of de Broglie's theory does not violate Bell's inequalities, but is not Lorentz covariant, while just tons of experiments and the everyday experience of cyclotron pattern accelerators and cosmic rays show that Lorentz covariance is real.

There is a recent modification to Bohm's theory that is claimed to be covariant, but I know nothing about it.

 

[jcsd]

You cannot derive QM from classical physics (just like you can't derive relativistic QM from QM or SR) it is 'new' physics. De Broglie's explanation as was is insufficent, though Bohm's extenstion of this explanation can describe QM it has several problems mentioned several times in this thread.

Generally you encounter huge problems when you try to create a realist explanation of QM.

 

[Albrecht]

And Bell's inequalities and the experiments, starting with Aspect's, that confirmed them knock simple hidden variable theories on the head.

It was widely discussed in the course of this series of threats that the assumption of de Broglie regarding the pilot wave has absolutely nothing to do with
1. Bell's inequality
2. the experiments of Aspect

Bell himself was always in favour of the pilot wave assumption. He worked for a long time at the Cern accelerator and, to my knowledge, never found an argument against the assumption that
1. the electron is a real particle
2. the pilot wave is responsible for the interference phenomena.

And by the way: where did I mention hidden variables?

But thanks for the reference to John Gribben. Shall try to get it.

Generally you encounter huge problems when you try to create a realist explanation of QM.

I know, of course, this argument. But it is too general and so it cannot clarify anything.

 

[jcsd]

Well huge problem no.1 is non-locality, which is very dificult to explain within a relist concept without introducing concepts such as the quantum potential leaving the theory ontologically unsatifying.

 

[Albrecht]

Well huge problem no.1 is non-locality

The pilot wave has nothing to do with non-locality.

If you throw a stone into the water it generates waves. Do we in this case have a problem with non-locality or with hidden parameters?

I guess we do not.

It is a similar process if an oscillating electron moves through the space an causes a surrounding wave.

 

[jcsd]

Au contaire the biggest tumbling block for Bohm's interpretation is that a non-local quantum potential may affect the particle and visa versa. There are reasons why the De Broglie-Bohm interpretation is not the convential interpretation.

 

[pelastration]

Albrecht speaks about de Broglie, you jcsd comes always back on Bohm.

 

[jcsd]

Originally posted by pelastration
Albrecht speaks about de Broglie, you jcsd comes always back on Bohm.

The reason for this is that Bohm is responsible for developing the pilot wave theory, so you can talk about De Broglie if you want but if your talking about a consistent pilot wave model of QM you have to talk about Bohm.

 

[Albrecht]

if your talking about a consistent pilot wave model of QM you have to talk about Bohm

I do not know where this (very common) misunderstanding comes from. Bohm had a very special interpretation about where the pilot wave comes from. He tried to generate a deterministic Schroedinger-like wave function, which is a different case.

The model I have explained is in contrast very easy. In this model an electron emitting a wave is quite similar to a radio antenna transmitting a wave. Do radio antennas have a problem with locality?

John Bell who worked on this topic for about 30 year (e.g. as a theoretical physicist at the Cern accelerator) stated that he never found a real argument against the pilot wave.

 

[jcsd]

Albrecht, Bohm's interpretation is the pilot wave interpretation, De Broglie's is just undeveloped version of this, certainly no-one with knowledge of QM would put forward De Broglie's explanation by itself.

I think the misconception is on your part.

Of course non-locality must involved as hv theory must be non-local.

 

[jcsd]

I'll also add De Broglie himself abandoned the pilot wave interpreation in 1935 due to it's non-locality.

 

[jammieg]

The question remains unanswered to my expert laymen's knowledge, why should one electron be affected by another that are not occupying the same apparatus at the same time? One particle's wake is influencing another particle's trajectory, so what is it that is retaining the information of the wake? If there were nothing to retain the information of the previous electron then a series of the apparatus all firing one electron should also when compiled produce a wave pattern, but if they don't then there is information being retained by something in each emission.