Atom & its structure.

[juanrga]

You stated 'electrons inside the atom are not waves but particles only'. Does that mean that electrons behave as waves only when they are outside the confines of the atom I.e. floating as 'free agents' beyond the reach of ''attracting- force' of positively charged protons (as actually happens inside the 'plasma' of a FUSION REACTER or inside the 'plasma' of FUSION REACTION taking place in the core of the SUN?)Your thoughts?

 

I think Juanrga means electrons are particles according to the QFT definition of a particle, ie an excitation or 'knot' if you will, in the fermionic quantum field.

Electrons can behave as classical particles or waves depending on the method of observation, but are by no means classical particles or waves.

 

Quantum field theory sees all spaces occupied by fermionic and bosonic quantum fields, including all space 'inside' an atom.

 

An electron is always a particle both inside and outside an atom.

 

I did not even mention QFT. I was discussing this from the quantum mechanical point of view because I assumed this was the OP goal.

 

According to QM an electron is a particle, a quantum particle. Ballentine's recent book on quantum mechanics points out how electrons are always particles and never waves:

 

Are "particles" really "waves"? In the early experiments, the diffraction patterns were detected holistically by means of a photographic plate, which could not detect individual particles. As a result, the notion grew that particle and wave properties were mutually incompatible, or complementary, in the sense that different measurement apparatuses would be required to observe them. That idea, however, was only an unfortunate generalization from a technological limitation. Today it is possible to detect the arrival of individual electrons, and to see the diffraction pattern emerge as a statistical pattern made up of many small spots (Tonomura et al., 1989).

 

The idea that electrons behave as waves or are waves is a misconception of quantum theory that "continues to flourish in popular texts and elementary text books" but not in more rigorous literature. A more complete discussion of the wave-particle misconception is available in the Klein site including several references.

Edited November 5, 2012 by juanrga

[chandragupta]

1352135850[/url]' post='711725']

An electron is always a particle both inside and outside an atom.

 

I did not even mention QFT. I was discussing this from the quantum mechanical point of view because I assumed this was the OP goal.

 

According to QM an electron is a particle, a quantum particle. Ballentine's recent book on quantum mechanics points out how electrons are always particles and never waves:

 

 

 

The idea that electrons behave as waves or are waves is a misconception of quantum theory that "continues to flourish in popular texts and elementary text books" but not in more rigorous literature. A more complete discussion of the wave-particle misconception is available in the Klein site including several references.

Thank you. You have really cleared the 'fog' regarding the electrons I.e. whether they are particles or waves or both.

[chandragupta]

1352124495[/url]' post='711680']

You stated that electrons can behave as classical particles or as classical waves depending upon the method of observation(i.e. depending upon the observer:- this last bit in bracket is mine add-on & not your's, just to make myself understand) but their inherent nature (my world & not your's :- just to make myself understand this difficult subject) is not that of either classical waves or that of classical particles. Would you be kind enough to elaborate on this (apparent ?) contradiction ? Thanks.

 

migL, Would you like to make any further comment re. this issue of 'wave-particle' characterization of the electrons?

[alpha2cen]

migL, Would you like to make any further comment re. this issue of 'wave-particle' characterization of the electrons?

 

In the case of wave property.

We can not find a light which has many kinds of wave length.

[O'Nero Samuel]

An electron is always a particle both inside and outside an atom.

 

I did not even mention QFT. I was discussing this from the quantum mechanical point of view because I assumed this was the OP goal.

 

According to QM an electron is a particle, a quantum particle. Ballentine's recent book on quantum mechanics points out how electrons are always particles and never waves:

 

 

 

The idea that electrons behave as waves or are waves is a misconception of quantum theory that "continues to flourish in popular texts and elementary text books" but not in more rigorous literature. A more complete discussion of the wave-particle misconception is available in the Klein site including several references.

If I may ask, what happened to the wave-particle duality part of the whole story?

 

If electrons are neither waves nor particles, but can be manupulated as both depending on the point of reference of the observer, then what are they really?

 

A segue, but not so far off the point. EM waves are produced by accelerating charges (electrons). Then if the electron is "orbiting" the nucleus, then it should be creating an EM wave of a constant frequency when in a certain energy level. I learn everything like I dont know; even our everyday 1+1.

[MigL]

If the electron is always a particle Juan, and a purely technological limitation is responsible for the statistical pattern's appearance as a wave, then what is it that is interfering with itself to produce the diffraction pattern. Particles, even statistically grouped particles, don't interfere with each other, only waves do.

 

This is an example of an experiment that will produce wave-like behaviour. There are others that will produce particle-like behaviour, Chandragupta, for a fuller understanding of this behaviour see the Wiki page on J.A. Wheeler's 1978 delayed choice ( thought) experiment or read Dick Feynman's lecture notes.

[chandragupta]

1352166895[/url]' post='711784']

If I may ask, what happened to the wave-particle duality part of the whole story?

 

If electrons are neither waves nor particles, but can be manupulated as both depending on the point of reference of the observer, then what are they really?

 

A segue, but not so far off the point. EM waves are produced by accelerating charges (electrons). Then if the electron is "orbiting" the nucleus, then it should be creating an EM wave of a constant frequency when in a certain energy level. I learn everything like I dont know; even our everyday 1+1.

 

Be kind. We shall get there in the end somehow.

 

1352177988[/url]' post='711794']

If the electron is always a particle Juan, and a purely technological limitation is responsible for the statistical pattern's appearance as a wave, then what is it that is interfering with itself to produce the diffraction pattern. Particles, even statistically grouped particles, don't interfere with each other, only waves do.

 

This is an example of an experiment that will produce wave-like behaviour. There are others that will produce particle-like behaviour, Chandragupta, for a fuller understanding of this behaviour see the Wiki page on J.A. Wheeler's 1978 delayed choice ( thought) experiment or read Dick Feynman's lecture notes.

 

Thanks. I shall do that.

 

1352165012[/url]' post='711782']

In the case of wave property.

We can not find a light which has many kinds of wave length.

 

1352165012[/url]' post='711782']

In the case of wave property.

We can not find a light which has many kinds of wave length.

Would be kind to explain in words this picturization?

[juanrga]

If I may ask, what happened to the wave-particle duality part of the whole story?

 

If electrons are neither waves nor particles, but can be manupulated as both depending on the point of reference of the observer, then what are they really?

 

A segue, but not so far off the point. EM waves are produced by accelerating charges (electrons). Then if the electron is "orbiting" the nucleus, then it should be creating an EM wave of a constant frequency when in a certain energy level. I learn everything like I dont know; even our everyday 1+1.

 

I think that I was clear when said that electrons are particles. Klein site is clear when says that electrons are a particular class of elementary particles. Ballentine is clear when says that an electron is a particle.

 

I think that it was clearly stated that wave-particle duality is a misnomer that arose from a misconception. But in Klein site you can find a more expressive quote: "The fact that true wave-particle duality does not exist may also be read off directly from the structure of QT" (QT means Quantum Theory).

 

If the electron is always a particle Juan, and a purely technological limitation is responsible for the statistical pattern's appearance as a wave, then what is it that is interfering with itself to produce the diffraction pattern. Particles, even statistically grouped particles, don't interfere with each other, only waves do.

 

This is an example of an experiment that will produce wave-like behaviour. There are others that will produce particle-like behaviour, Chandragupta, for a fuller understanding of this behaviour see the Wiki page on J.A. Wheeler's 1978 delayed choice ( thought) experiment or read Dick Feynman's lecture notes.

 

Yes, the electron is always a particle, but you misread the quote, because nowhere it says that "a purely technological limitation is responsible for the statistical pattern". It says something completely different. Let me add that "particle" in QM does not mean Newtonian particle. The motion of a quantum particle as the electron is very different from the motion of a billiard ball.

 

Both the book cited and the Klein site explain very-well how the observed 'wave-like' behaviour is perfectly compatible with the fact that an electron is always a particle and never a wave. I think that the central misconception of the concept of "wave-particle duality" is perfectly reflected in Klein note #40.

 

Ballentine textbook is rather modern and rigorous. It avoids the mistakes found in other textbooks. The level of rigour is light-years that of the Wikipedia page. This textbook contains lot of modern results which you cannot find in Feynman lectures.

Edited November 6, 2012 by juanrga

[MigL]

Sorry may have misread some of your post, but I still had a problem with what you wrote until your last clarification because you do not differentiate between particles.

I now agree with you 100% since I know some quantum theory and QFT from a BSc in physics, but when you state that an electron is always a particle someone who doesn't have the required background will assume you mean the classically defined Newtonian particle. You should definitely add the qualifier that you mean a quantum particle, which is NOT the same as a classical particle, as I did when I gave the QFT example, to remove all ambiguity.

[juanrga]

Sorry may have misread some of your post, but I still had a problem with what you wrote until your last clarification because you do not differentiate between particles.

I now agree with you 100% since I know some quantum theory and QFT from a BSc in physics, but when you state that an electron is always a particle someone who doesn't have the required background will assume you mean the classically defined Newtonian particle. You should definitely add the qualifier that you mean a quantum particle, which is NOT the same as a classical particle, as I did when I gave the QFT example, to remove all ambiguity.

 

Excellent advice . I used the term "quantum particle" in above posts (e.g. day 5), but I forgot to use the term in my first post.

[granpa]

http://arxiv.org/abs/1002.3880

 

Diffraction patterns of electrons are believed to resemble those of electromagnetic waves (EMW). I performed a series of experiments invoked to show that the periodicity of peaks in the diffraction diagram of electrons is concerned with the periodicity of the arrangement of scattering centers in the diffraction grating in combination with the supposed character of the spatial structure of the electron as a system of regularly spaced concentric shells of elasticity. I started from the experiment on the diffraction of electrons and EMWs at the sharp edge of the opaque half-plane. This simple scattering configuration enabled me to discriminate between the re-radiation mechanism of the wave diffraction and ricochet scattering of electrons on the edge of the half-plane. Then I made experiments with scattering on composite objects proceeding step by step from a single straight edge to a couple of edges (one slit) and then to four edges (two slits). Thus I succeeded in interpretation of the double-slit diffraction (four straight edges) in terms of the scattering on a single edge. I managed also to observe the electron's trajectory. Equipping the slit's edge with a semiconductor sensors I registered the passing of the electron through the slit detecting simultaneously a weaker signal at another slit. This technique appeared not to destroy or disturb the "interference" pattern. Closing one slit by inserting therein a transparent for EMWs piece of dielectric I have found that the scattering pattern beneath this slit vanishes while the scattering pattern under the open slit remains as before when both slits were open. This experiment indicates that the electron "interferes" with its electromagnetic component passed via the slit plugged by the transparent for it dielectric