Are electrons wave or a particle?

  • #1
benzun_1999
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Are electrons wave or a particle???

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.
:wink:
 
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Answers and Replies

  • #2
It's not a question of "or".

We simply lack the ordinary frame of reference for dealing with subatomic particles.
 
  • #3
Janus
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Like anything else in the sub-atomic world, electrons are neither waves or particles in the truest sense, but display the properties of both, just as photons do. Most of the time we see the particle type aspects of the electron more readily because its associated wavelength is so small.
 
  • #4
VBPhysics
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I almost shutter to answer this question, but:

Electrons behave in both ways, but what we see depends on the experiment, and what we are looking for. When Experiments are testing and look for a wave nature they find it, and when they look for a particle nature they find it. This should be very distrubing on the surface because it means that the results of an experiment are in a way altered by our preconceived notions of what should be, not governed by what is. It is odd, but nevertheless a well established nature of the subatomic world.
 
  • #5
Albrecht
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Like anything else in the sub-atomic world, electrons are neither waves or particles in the truest sense, but display the properties of both, just as photons do.

This is only one (but presently the most common) interpretation of the particle/wave phenomenon.

According to Louis de Broglie an elementary particle is a particle in the true sense. But it has a wave around it, called the piloting wave. This wave guides the particle and causes the effects like the scattering at a double slit. The wave is caused by the internal oscillations of every elementary particle. (De Broglie received the Nobel price in 1929 for his detection of the wave behaviour of particles).

Bohr and Heisenberg have - as we know - refused this interpretation. John Bell has investigated the available literature about it and has stated in his book "Speakable and Unspeakable in Quantum Mechanics" that he never found any arguments used by Bohr or Heisenberg, why the approach of de Broglie would not be possible. De Broglie's position was just ignored by both, and still it is by the majority of the physical community.

According to John Bell there is no argument which would refute the opinion of de Broglie. The advantage if this approach is that it is very easy to understand, and it takes the mystery away from quantum mechanics.
 
  • #6
jimmy p
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Electrons and Photons follow a theory called wave-particle duality, where as they are classically viewed as either a wave or a particle, they share characteristics of both. Electrons display wave properties because their exact position cannot ever be determined but there is an area in which they could exist. The only way to determine how they work is by giving them a wavelength. Likewise with photons, which are said to have particle properties to explain the photoelectric effect.
 
  • #7
Albrecht
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Electrons and Photons follow a theory called wave-particle duality ...
But, as I wrote, this is only one of the existing theories. According to de Broglie, Einstein, Bell etc. it is different.

If we measure the position of an electron, we measure in fact the position, the frequency, and the phase of the wave. We know (also from radio technology) that we have to measure a high frequency signal for a sufficiently long time to know exactly it's parameters. It is the same when measuring the electron's wave. The uncertainty of the measurement of the wave results in an uncertainty about the position of the particle. That exactly is what Heisenberg's uncertainty rule says.

So, the position of the electron is not uncertain, but our knowledge of it is.
 
  • #8
FZ+
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IIRC, what you are referring to is the Debroglie-Bohm interpretation. In other words, what debroglie-bohm postulate is the existence of non-local hidden variables. Yes, there is no current way to rule this out, but there is no way to rule it in either. The interpretation is also in serious conflict with relativity over FTL information transmission, so most put it on the shelf.

Very easy to understand does not always equal true.
 
  • #9
ahrkron
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"Wave-particle duality" is the name given to a property of the behavior of atomic phenomena.

The "theory" is QM, not "wave-particle duality".

Maybe you meant that there are different interpretations for the formalism, which is true.

Also, it is fair to say that the majority of physicists favor the interpretation that the position of the electron is indeed undetermined until measurement. It is not a matter of our knowledge of it.
 
  • #10
Albrecht
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The interpretation is also in serious conflict with relativity over FTL information transmission, so most put it on the shelf.

The interpretation as I gave it is in no conflict with relativity.

From the Dirac function of the electron it follows that the inside of the electron oscillates (i.e. it orbits) with c. If this is true then the field which keeps the electron together will be an alternating field. This field propagates with c into all directions. If the electron moves towards a double slit the field builds necessarily an interference pattern. This pattern guides the constituents of the electron through the slit. If the electron is now registered behind the slit, then the experimenter will see the interference result and he has the impression that the electron is a wave.

The process described above is not a mere possibility but a necessity. And there are no hidden variables involved into this process.

To my knowledge no one has ever argued in detail that this will not happen.

Please refer to John Bell for the literature situation.
 
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  • #11
FZ+
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This field propagates with c into all directions.
In that case, this would be in direct contravention of the results of the Aspect experiment.
 
  • #12
Tyger
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The best description I know of about what an electron is, which is to say how it behaves, is one of the Feynman Lectures titled Bullets and Waves. It's a must read if you want to understand quantum mechanics and the behavior of electrons.
 
  • #13
pelastration
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Thanks Albrecht for bringing up de Broglie. Very interesting and logic.

FZ+, can you explain why this is contradicting Alain Aspect's Experiment?
 
  • #14
As part of my case for a Single (Vacuum) Force Theory I made notes on a new interpretatation of The Quantum Hall Effect and showed a relationship between the vacuum wave and the electromagnetic wave. I have never received any comment on this page.
As it explains the relationship between wave and particle perhaps someone would make a comment. (Go to my home page via the 'Members List')
 
  • #15
FZ+
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As part of the aspect experiment, a change in the experimental setup is made while the photons are en route, such that the only way any information can be transmitted from the site of the change to influence the polarisation of the photon is by breaking the c limit. Yet the results obtained still somehow show the same violations as predicted by QM.

The result of this is that either the hidden variables are non-local, and thus break the light barrier, or they don't exist at all. If the field that guides the photons propogates at c, there is no way in which the change can influence the photon, which is outside it's light cone.

On the other hand, there are some loopholes, but they are tight ones.
 
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  • #16
Albrecht
159
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Every field we know in physics propagates at the speed of of light c.

The field which is caused by the electron propagates at the same speed. There is nothing special about it.

Something must be severely mixed here.

The Aspect experiment is about entangled photons. That is a completely different case.

Thank you, pelastration, for your comment. De Broglie is by my understanding one of the greatest physicists of the 20th century. Many physicists are not aware of this.
 
  • #17
FZ+
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The Aspect experiment is about entangled photons. That is a completely different case.
How is it different? If we follow the hypothesis that the electrons, and photons are existent as discrete particles guided by a field, the only option to allow the entangled spooky action at a distance effect is to make the field a non-local variable in the motion of the particle. Else, we would be forced to imply the conventional uncertain state of the particle to account for this phenomena, which would then render the existence of a field superfluous.
 
  • #18
jcsd
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Bohmian Mechaincs is in conflict with relativity as the quantum potential can affect particles non-locally which for a filed would be forbidden by relativity.
 
  • #19
metacristi
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Bohm's interpretation does violate relativity indeed (as it is conceived today) but not because it implies an instantaneous transfer of information.This happens because the quantum potential constitutes an absolute system of reference,something expressly forbidden by relativity.In Bohm's 'pilot-wave' interpretation the quantum potential is seen as pervading all space,local changes in the state of a quantum particle provoking the instantaneous change of the quantum potential in the whole of space.This does not imply an instantaneous transfer of information any more than the 'intrinsic' nonlocality assumed by the usual Copenhagenist approach (the pair of entangled particles form a single 'object',their wavefunction being spread over space).

Anyway we must never forget that relativity cannot even be accomodated theoretically with the standard formalism of QM.Finally since the experiment remain the 'highest authority' there is no sufficient reason to rule out de Broglie-Bohm pilot-wave' interpretation [it is equally supported by all existing experiments as the copenhagenist interpretation of QM] in spite of the preferential frame problem [yes Michelson Morley's experiment does not rule out the possible existence of an aether interacting very faintly with the macroscopic level,as the quantum potential is].
 
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  • #20
jcsd
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Yes relativtly as a whole cannot be accomadated with QM but special relativity can be accomadetd with QM which means that Bohmian mechanics must be rejected in relativistic quantum mechanics.

Also the matter-wave interpretation would predict that a single atom would have a dipole as the electron has a definte postion within the atom however there is no dipole observed in a single atom.
 
  • #21
metacristi
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Yes relativtly as a whole cannot be accomadated with QM but special relativity can be accomadetd with QM which means that Bohmian mechanics must be rejected in relativistic quantum mechanics.


This is not enough to rule out Bohm's interpretation,in fact,from what I've read,there is underway a very serious research in order to make bohmian mechanics relativistic (of course not totally compatible with all postulates of relativity as it is now).


Also the matter-wave interpretation would predict that a single atom would have a dipole as the electron has a definte postion within the atom however there is no dipole observed in a single atom.


From all I've read so far Bohm's interpretation makes exactly the same predictions as the Copenhagen Interpretation,there is no experiment,as of now,which to make the difference between them (not a big surprise given that both have at base the same mathematical formalism).

There were some claims,on the net,that Bohm's theory make some different predictions and therefore there is a way to make the difference between copenhagenism and bohmian mechanics.The claims went further,that Bohmian mechanics was falsified but from what I've read there is no real base for the claim that copenhagenism and bohmian mechanics really make different predictions.

There is an objection to bohmian mechanics here for,indeed,it cannot explain in a satisfactory manner (from all I know at least) why a electron (considered as being only particle) do not fall in the nucleus.However this is not enough,the existence of some unexplained yet phenomena never count as a disproof of a certain theory.
 
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  • #22
metacristi
265
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More exactly the objection to Bohm's interpretation mentioned in my above post is that for some orbitals,for example those in the state with n=2,'p' and so on which do not have spherical symmetry,the electrons are in fact accelerating and should radiate away energy.Or this is against the postulate stating that they do not radiate energy when being in an allowed stationary orbit.However this does not mean there is no valid explanation,though many disagree with it.As Vigier has proposed maybe electrons do radiate energy in fact only that the energy loss is negligeable,the wavelength of this radiation being extremely large.I find this argument fair enough,well beyond an ad hoc explanation,anyway 'working' for all our actual practical purposes.Indeed it is fully compatible with Bohr's postulate the latter being an idealized case of Vigier's proposal.
 
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  • #23
Albrecht
159
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The idea that the electron (like the other elementary particles) is a real particle, which is guided by the field which is caused by it's internal forces, has not much to do with Bohm's quantum mechanics. And it is of course not in conflict with relativity. The field propagates with c, which is standard for relativity.

It is one electron at a time which is guided by it's own field. So there are no entangled pairs of particles.

This is very classical and it works perfect to explain the interference at a double slit.

De Broglie explained all this in his famous papers of 1923 and 1924, and he receive the Nobel price for it. I do not know of any serious arguments against this explanation.
 
  • #24
jcsd
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Albercht there are many serious ontological arguments against Bohm's interpretation which is the reason that it is not the standard interpretation, mainly that it is a non-local realist theory and thus in conflict with relativity (of course others that centre around the nature of the quantum potential).
 
  • #25
pelastration
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de Broglie and kirilyuk

Andrei Kirilyuk has focused on deBroglie. I believe you need to read some of his publications when you discuss a de Broglie piloting wave.


http://arxiv.org/pdf/quant-ph/9911107

ABSTRACT. A physically real wave associated to any moving particle and propagating in a
surrounding material medium was introduced by Louis de Broglie in a series of short notes in 1923 and
in the most complete form in his thesis defended in Paris on the 25th November 1924. This result,
recognised by the Nobel Prize in 1929, gave rise to the whole field of the ‘new physics’ known today as
‘quantum mechanics’. However, although such notions as ‘de Broglie wavelength’ and ‘wave-particle
duality’ have become ‘conventional’ in the standard quantum theory, it actually only takes for granted
(postulates) the formula for the wavelength (similar to other its formally postulated ‘results’) and totally
ignores the underlying causal, physically real and transparent picture of quantum/wave behaviour
outlined by Louis de Broglie in his thesis and further considerably developed in his later works, in the
form of ‘double solution’ and ‘hidden thermodynamics’ concepts (the first of them is only
mechanistically imitated within the over-simplified ‘interpretation’ of ‘Bohmian mechanics’, now often
presented as ‘causal de Broglie-Bohm theory’). The payment for such crude deviation from the basic de
Broglian realism is the absolute domination of the fundamental science by purely abstract, detached from
reality and mechanistically simplified schemes made of formal symbols and rules that has inevitably led it
into the deep impasse judiciously described today as the ‘end of science’. However, an independent
approach of the ‘quantum field mechanics’ (quant-ph/9902015,16, gr-qc/9906077) created recently
within the ‘universal science of complexity’ and the related ‘dynamic redundance paradigm’
(physics/9806002) leads to confirmation and natural completion of unreduced de Broglie's results
eliminating all their ‘difficult points’ and reconstituting the causally complete, totally adequate and
naturally unified picture of the objective reality directly extendible to all higher levels of the complex
world dynamics.

Kirilyuk: http://arxiv.org/pdf/quant-ph/0101129

We have demonstrated, in the previous section, how the Schrödinger equation and the causally
extended wavefunction naturally emerge from the unreduced analysis of the interaction process in the
simple, a priori homogeneous system of two coupled protofields.
---
pag: 32
It is important to emphasize that the obtained generalisation is not a formal mathematical
generalisation of the particular equations. As we have shown above, the Schrödinger equation describing
system complexity development at its certain level is causally derived from the unreduced analysis of
interaction between entities of lower level(s), which always includes the dynamic redundance and
entanglement phenomena totally absent in the canonical science that simply postulates, in each particular
case, the ‘suitable’ mathematical form of the main dynamic equation and tries to fit its severely limited,
dynamically single-valued solutions to the observation results. This blind trial-and-error search and purely
technical tricks of the conventional empiricism lead to the abuse of ‘mysteries’ and abstraction at the
lowest complexity levels of the unified world dynamics and to practical absence of any objective
description for higher levels of complexity, where the number of necessary ‘postulates’ grows
dramatically, in proportion to realisation number determining the system complexity. The unreduced
derivation and complex-dynamical interpretation of the universal Schrödinger formalism provide, in
particular, the inherent creativity and dynamic adaptability for the emerging structures that make them
realistically ‘alive’/self-developing, while being totally absent in the dynamically single-valued projections
of the canonical science, they should be artificially added to them within that approach in an inevitably
incomplete form.

All arXiv's of Andrei Kirilyuk : http://arxiv.org/find/physics/1/au:+Kirilyuk_A/0/1/0/all/0/1

---
To me Kirilyuk's protofields is like several spacetime layers which interact.
Layered spacetime is created by self-penetrating unbreakable Brane.
On those local spots spacetime is multi-layered: so concentrated, more dense and less elastic.
Multi-layers create local internal friction which brings thermodynamics, EM, etc.
The brane acts as gravity. Everything is interconnected.
This approach fits in de Broglie's approach.

Dirk
 
  • #26
metacristi
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jcsd

Albercht there are many serious ontological arguments against Bohm's interpretation which is the reason that it is not the standard interpretation, mainly that it is a non-local realist theory and thus in conflict with relativity (of course others that centre around the nature of the quantum potential).


It's not so simple,what ontological arguments?We do not have direct access at quantum level,so that we cannot directly 'probe' the quantum level,consequently there is no directly 'observed' ontology to attach to the standard formalism of QM.All we can do is to interpret the standard mathematical formalism by attaching an ontology compatible (having explanatory power too not merely being neutral) with all observed facts (experiments) we can reliable observe (indirect observations as in Rutherford's experiment are accepted).This is exactly what the different valid interpretations do,they all make exactly the same predictions,the ontology assigned is interpretation related.

Are they capable to explain all such phenomena in a compelling manner which to make a clear difference between them?I'm afraid not.The reality is that all interpretations have problems,the Copenhagen Interpretation included.How is the operational-positivistic approach advocated by the Copenhagen Interpretation 'forced upon us' as some claim?We can hardly see its proposals as proposing an ontology for the quantum level.Why should the universe suffer a sudden change when the wavefunction collapse?How is Bohr's answer to EPR relevant (the observed and the observer are a single entity) to the quantum entanglement?This is only an 'intrinsic' explanation that many finds hardly satisfactory.That's why there are so many scientists who keep trying...

In fact only the standard mathematical formalism makes predictions that are consistently 'confirmed' practically and this is enough for all our practical purposes.There are many scientists who do not put too much faith in the usual ontologies assigned,they advocate the so called 'shut up and calculate' interpretation.At least for the moment.

Even if we accepted that the Copenhagen Interpretation is really superior to all other (but I don't think is the case) we simply do not have sufficient arguments to claim that it is true or the best interpretation possible.It is even possible that all existing interpretations are far from the ontological reality.

The explanation for the success of the Copenhagen Interpretation has a historical and a pragmatic aspect.It was the first succesfull interpretation and in the same time the simplest (given that it hardly propose an ontology).Had de Broglie not gave up so easily his 'pilot-wave' intepretation of 1926 due to Born's objections maybe the causal interpretation would have won the battle,who knows?

Basically his interpretation is the same as Bohm's approach,but there are some differences regarding the nature of the particle and of the associated wave (distinct entities):in de Broglie's approach there exist only fields,particles being points of high intensity,whilst in Bohm's approach particles are distinct from the fields (classical and the non local quantum potential).

Unfortunately de Broglie did not pursue his work so that the 'fathers' of Copenhagen Interpretation claimed victory,'crowning' it as perpetual winner by making also the bold claim that there cannot exist a better interpretation.

The next generations of scientists grew in this atmosphere dominated by the positivistic approach,including it's 'final' claims.It was not a big surprise therefore that Bohm's attempt (and later Everett's) was meet with manifest hostility.

Bell (a supporter of hidden-variables interpretations himself) even wrote once that his generation was 'brain-shawed' with the finalistic claims that the copenhagen interpretation is the only reasonable interpretation,that Von Neumann proved the physical impossibility of hidden variables and so on.Only in the past 15-20 years have alternative interpretations began to be regarded with attention by the Establishment.There are now much more scientists who ceased to believe in the mith of the Copenhagen Interpretation,quantum electrodynamics is simply not enough,indeed the future might be full of surprises...
 
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  • #27
jcsd
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I'll have to go out and play football now, but when I get back my QM textbook has a detailed explanation of Bohmian mechanics along with the reasons why it is rejected as the convential interpretation.
 
  • #28
Albrecht
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Albercht there are many serious ontological arguments against Bohm's interpretation which is the reason that it is not the standard interpretation
How often shall I repeat that I do not present here the theory of Bohm?

What I have explained is what de Broglie and Dirac have said about particles in general and about the electron as a special case.

That is all quite simple. I do not repeat what I have written in the previous post.

Who did have the crazy idea to refer to Bohm when I explained the particle wave approach of de Broglie???

I thank everybody for the detailed information about de Broglie, who was one of the greatest (by my opinion). I shall come back to those threats tomorrow.
 
  • #29
jcsd
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Albrecht the reson why Bohm get's mentioned as soon as you mention De Broglie is that he devolped the theory into the QM interpretation it is today and matter waves are often called De Broglie-Bohm waves.
 
  • #30
Albrecht
159
2
matter waves are often called DeBroglie-Bohm waves
The problem seems to me that the "Copenhagen Interpretation" is so dominant in this time that all alternatives are treated like one single alternative theory.

I have refered to the original idea of deBroglie and I used the Dirac function of the electron. However, I also use the actual results of particle physics which were not known by both. And further the causes of relativity which were not treated by Einstein, but give us a lot of additional information. I have put this together in a web site www.ag-physics.org/structure

Thank you, pelastration, for your link to the work of Andrei Kirilyuk. The summary looks interesting. Also thanks to you, metacristi, for the informations given.
 
  • #31
jcsd
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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.
 
  • #32


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.
:wink:

The most accurate answer is that they are neither.

Pete
 
  • #33
Surely they are both, the particle is bound, the wave extends by influence, to infinity.
 
  • #34
tribdog
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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
 
  • #35
Albrecht
159
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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.
 

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