Talk:Electron/Archive 4

Archive 1

Archive 2

Archive 3

Archive 4

confused!

where are electrons found? —Preceding unsigned comment added by 74.128.126.20 (talk) 01:59, 26 September 2008 (UTC)

They are pretty much ubiquitous because they form parts of atoms. You experience them when you get an electrostatic shock or watch a lightning bolt.—RJH (talk) 18:54, 27 September 2008 (UTC)

How can a particle with mass exist with no spatial extent? With no spatial extent the electron must have infinite density. The only object with infite density I know is a black hole. Are electrons black holes? —Preceding unsigned comment added by 91.7.180.6 (talk) 08:27, 9 March 2009 (UTC)

The same can be said of the electron's charge: if it has no spacial extent, then the charge density is also infinite. I don't think physics has a good answer for this one yet. One possibility is string theory. Another I've seen mentioned is that space and time are themselves quantized. See also black hole electron.—RJH (talk) 21:44, 9 March 2009 (UTC)

The answer is that quantum physics prevents anything from being an actual point. The universe has a smallest scale, leading to the "uncertainty principle" and conjugate variables. Basically, you cannot say an electron is at some exact spot; you can only ask what is the probability that it is within some specified region. The smallest region you can specify is the planck length.

In calculations, they basically say "don't worry about it". Draw a very very small radius around the point and consider the effect outside that radius.

—Długosz (talk) 21:50, 18 November 2009 (UTC)

Potential (zap!) merge-in candidate

Could someone with a caring hand please take a look at the unattractive and unloved Speed of electricity? Perhaps it could be redirected to Electron#Motion and energy? -- Fullstop (talk) 02:50, 25 February 2009 (UTC)

Personally I think the topic is worthy of a separate article. It also covers the speed in a conductor, which is in a different section of this article. You're always free to dup. cites from this article, if need be.—RJH (talk) 19:39, 25 February 2009 (UTC)

FAC issues check list

Many of the issues raised during the FAC have been addressed. Here are the remaining issues that need resolving before another FAC attempt is made.

• "Chemical bonds between atoms were explained in 1916 by Gilbert Newton Lewis, as the interactions between their constituent electrons." (Interactions between electrons are always repulsive, so could hardly explain chemical bonding: the Lewis model of covalent bonding is based on the sharing of electrons between atoms.)

  Fixed. Ruslik (talk) 11:54, 24 March 2009 (UTC)

• "As the chemical properties of the elements were known to largely repeat themselves according to the periodic law, in 1919 the American chemist Irving Langmuir suggested that this could be explained if the electrons in an atom were connected or clustered. Groups of electrons were thought to occupy a set of electron shells about the nucleus, providing the necessary clustering." (This insight is due to Lewis (1916, in the same paper as his bonding model), although Langmuir's paper proved influential in popularizing it – and provoking a bitter priority dispute.)

  Clarified. Ruslik (talk) 11:54, 24 March 2009 (UTC)

• "For the 51 GeV electron above, the wavelength is small enough to explore structures well below the size of an atomic nucleus." (The wavelength is smaller than the size of the atomic nucleus, and the energy of the electron is higher than many of the forces that hold the nucleus together, but you shouldn't imply that you could make an electron microscope out of 51 GeV electrons!)
  • As there is no longer anything in this paragraph, or the section either, that suggests an electron microscope, I'm going to mark this as done. Particle accelerators have already been mentioned as striking a static target with electrons.—RJH (talk) 02:13, 22 March 2009 (UTC)
• Applications: this looks a bit unstructured, for example, the electron microscopes appear both in Industry and Laboratory, but it's not clear why. I would do a separate section for electron microscopes. I feel that the applications in general are underrepresented, for example compared to the lenghty history section.
  • I did a re-organization, but the section still needs more work.—RJH (talk) 02:41, 22 March 2009 (UTC)
• I'm not a connoisseur of these matters, but I think you should sketch how an electron microscope or the surface imaging techniques work. Also, are LEED and RHEED primarily industry-used techniques? It looks like they belong to laboratory. But actually I think the applications section might benefit from a restructuring: ordering the applications by the specific feature of electrons they use could make it all more coherent.
  • I've added some additional details about the LEED/RHEED and inserted a brief description of the electron microscope.—RJH (talk) 17:21, 23 March 2009 (UTC)

—RJH (talk) 19:16, 13 March 2009 (UTC)

The first one is mine, so I ought to take responsibility for it. Any help is welcome ;) Physchim62 (talk) 19:27, 13 March 2009 (UTC)

Thanks. I've been trying to get to these, but other priorities have been keeping me busy.—RJH (talk) 22:34, 14 March 2009 (UTC)

Uncertainty in proofreading

• Paragraph 5 of Electron#Discovery says "a clouds of charged water droplets". Should that be "a cloud of charged water droplets" or "clouds of charged water droplets"? -- Wavelength (talk) 21:54, 13 April 2009 (UTC)

It should probably be "clouds of charged water droplets" to match the plurality of "experiments". Thanks for catching that.—RJH (talk) 22:22, 13 April 2009 (UTC)

• Paragraph 2 of Electron#Atomic theory says "the Lewis' static model of atom". Should that be "Lewis' static model of an atom", "Lewis' static model of the atom", "Lewis' static model of atoms", "the Lewis static model of an atom", "the Lewis static model of the atom", "the Lewis static model of atoms", or something else? -- Wavelength (talk) 22:26, 13 April 2009 (UTC)
  • Various sources use "static model of the atom" or "static atomic model". I'll just insert a 'the', as I think that was the intent of the author.—RJH (talk)
• The caption for the image for Electron#Conductivity is "Lightning is an example of the phenomena produced by triboelectricity." This makes me question the "correction" that I made to paragraph 1, where I changed "phenomena" [plural] to "phenomenon" [singular], understanding "triboelectricity" to be the one phenomenon referred to. If what is meant is "the various phenomena caused by triboelectricity", I recommend that the text be clarified accordingly. -- Wavelength (talk) 15:31, 14 April 2009 (UTC)
  • I changed the paragraph to use "triboelectric effect".—RJH (talk) 19:42, 14 April 2009 (UTC)

Quibble

I had a minor quibble about this statement:

The curving motion creates a centripetal force on the particle, and this acceleration causes the electron to radiate energy in the form of synchrotron radiation.

Isn't it the magnetic field that creates the centripetal force on the charged particle? The curving motion would create a centrifugal force.—RJH (talk) 19:43, 14 May 2009 (UTC)

I attempted to remedy this in a slightly different manner.—RJH (talk) 17:50, 25 May 2009 (UTC)

Cooper Pairs

"(Cooper pairs are separated by roughly 100 nm, so they can overlap each other.)[114]" That is not what is said in reference 114. The radius of the sphere of influence of the cooper pair on the surrounding lattice is roughly 100nm. The two electron probability distributions forming the cooper pair are not physically separated - they occupy the same space in the sphere - however, the volume of that space is quite large, so if you tried to determine the positions of the two electrons (the experiment would destroy that cooper pair) in the sphere, they would probably be quite separated. Typically, there are 10^6 cooper pairs in the volume of a sphere of 100nm radius, so there is significant overlap between the sphere of influence of one cooper pair and another. I don't know what is meant by the statement "Cooper pairs are separated by roughly 100 nm". —Preceding unsigned comment added by 205.250.252.133 (talk) 06:13, 17 May 2009 (UTC)

I changed the wording to remove the ambiguity. Thanks.—RJH (talk) 19:24, 18 May 2009 (UTC)

Lead

An anonymous editor decided to completely reorder the lead section. I took exception because I believe the current ordering is a logical arrangement that begins with the electron properties and then later introduces their interaction. I.e. it moves from the core topic outward. The original arrangement also more closely aligned with the order of presentation in the article, and it is limited to only four paragraphs per the WP:LEAD policy. Finally, some of the modified wording may not be in compliance with wikipedia policy.—RJH (talk) 17:49, 25 May 2009 (UTC)

Recent revert

I would like to suggest that the electron is an element. In any atom, the electrons are what you see because only they interact with light and not the nucleus. Also, every physical reaction one has with the world involves exclusively contact and forces between electrons, or between electrons and photons, except when you come into contact with radioactive substances. Also, Theodore W. Gray has made a periodic table tile of the electron, with symbol e⁻ and atomic number of −1. My reference is [1]. I will now revert it back to my old version, on account of this. --116.14.27.127 (talk) 05:21, 3 June 2009 (UTC)

The problem is that this violates our no original research and verifiability policies. Such a claim would have to be substantiated by several reliable sources including peer-reviewed journals with good reputations in the scientific community before Wikipedia could publish it. Enviroboy^Talk_Cs 05:39, 3 June 2009 (UTC)

If you say so. Then revert it. I'm pretty new to Wikipedia so I may not know all those policies. How do you even create an account? --116.14.27.127 (talk) 07:58, 3 June 2009 (UTC)

A good starting point is the Help link in the interaction box at left.—RJH (talk) 18:46, 4 June 2009 (UTC)

Charge on ELECTRONS.

Do anyone know how electrons get a charge? —Preceding unsigned comment added by 59.95.23.59 (talk) 06:58, 5 July 2009 (UTC)

It's an intrinsic and fundamental property of the particle. Other than that, I think physicists are still working out the underlying mechanisms that give particles their various charges. See Theory of everything, for example.—RJH (talk) 17:45, 5 July 2009 (UTC)

no known substructure ?

The head paragraph states that the electron "has no known substructure and is believed to be a point particle.", yet there is a section named "Subparticles" that states:"Electrons, when tightly confined at temperatures close to absolute zero, split into two subparticles, spinions and holons, in order to participate in quantum tunneling.". I wonder if there is a contradiction here. --190.245.211.195 (talk) 19:05, 1 August 2009 (UTC)

This is about quasiparticles is solids, which are quanta of excitation in the collective of many electrons. The real electrons in the vacuum are point-like. Ruslik_Zero 19:32, 1 August 2009 (UTC)

Point-like?

From where follows this property of the electron to be point-like?--84.232.141.38 (talk) 09:20, 8 May 2010 (UTC)

Experiments to measure size have been unsuccessful, therefore no size, thus point like. Although this can be wrong from a number of perspectives. One is if it is a standing EM wave, then calling it point like is incorrect. Daniel.Cardenas (talk) 16:35, 8 May 2010 (UTC)

then how big is the point ? and what happens at the surface of this point ? —Preceding unsigned comment added by 82.217.115.160 (talk) 22:24, 11 May 2010 (UTC)

A point has no size and no surface. ;) —Preceding unsigned comment added by 79.231.88.135 (talk) 21:42, 24 July 2010 (UTC)

An electron may be treated as a point-like particle within certain contexts. If we are talking about electrodynamics/statics, then we should reference (to be found and verified) that Coulomb's law is valid for distances as short as $10^{-11}$cm in which case, we may arguably consider electrons as "point-like" particles. I believe a reference for this point is made in Edward M Purcell's book, "Electricity and Magnetism". Classically, the radius of an electron is 3 femtometers (while, surprisingly, that of a proton is 1 femtometer!) -- feel free to find that reference. In Purcell's book (2nd ed, p 7), "In our study of electricity and magnetism we shall treat the charged particles simply as carriers of charge, with dimensions so small that their extension and structure is for most purposes quite insignificant." -- i.e. "point-like" in nature. "points" are purely mathematical abstractions and anyone who believes that pure mathematics has anything to do with the real world is in for a fun ride. —Preceding unsigned comment added by Tjlafave (talk • contribs) 22:18, 24 July 2010 (UTC)

If the electron is an elementary particle then where do the photons come from when they collide with there antiparticle. 121.210.36.245 (talk) 01:30, 23 March 2012 (UTC) 23-3-12

Unsourced paragraph

I removed the following paragraph because I was unable to find a suitable source, and I'm not clear that it was helpful to the lay reader:

Because the electron is a fermion, such wave function must take into account the electron's spin state, particularly where the spin may be altered by a magnetic field. A spinor-valued wave function should be used, and, in Schrödinger's theory, the electron density consists of two additives, which are squares of absolute value of each complex-valued component, called spin-up and spin-down.

See, for example, Wikipedia:Make technical articles accessible. Perhaps it would be better presented on the wave function page?—RJH (talk) 21:40, 4 August 2009 (UTC)

FAC Comments from TimothyRias

First impression: looking good. I have some comments most of them minor, but most need to be resolved before FA.

General

• Formulas need interpunction. Formulas are part of the sentence structure and thus need suitable interpunction. When a formula is the end of a sentence it needs a period. (Which needs to be inside the math tags per WP:MOSMATH.) When the sentence continues with 'where' it usually needs a comma. The article is currently missing interpunction on pretty much all formulas.

  Fixed. Ruslik_Zero 12:54, 23 August 2009 (UTC)

  If you're not going to put the interpunction inside the math tags, then you need to put both the math and the interpunction in a {{nowrap}} template to prevent the interpunction wrapping separately from the equations.{TimothyRias (talk) 10:05, 24 August 2009 (UTC)}

  I moved all punctuation inside formulas. Ruslik_Zero 13:18, 26 August 2009 (UTC)

Lead

• Some paragraphs illogically combine subjects. For example the second paragraph starts out discussing the history of the electron, and somehow ends up discussing its statistical behavior.
• If you are going to stress that electrons make up only 0.06% of an atoms mass, you should also mention that they account for about 99% for the physical and chemical behavior of atoms. Actually, this might be a good sentence to just drop from the lead. It will make the overall structure of the paragraph better.
• The last paragraph needs some work. The first part seems to discuss the creation and 'destruction' of electrons. As it written now it seems to be self-contradictory first stating that electrons are created in the Big Bang and lost in nucleosynthesis, but later adding other possibilities. I'd suggest something along the line

'Most of the electrons in the universe were created in the big bang, but may also be created through beta decay of radioactive elements and in high-energy collisions. Electrons may be destroyed through annihilation with positrons, or may be absorbed during nucleosynhtesis in stars.'

Don't take this as the literal texts as it needs expansion here and there, it is meant as an example of a more balanced logical structure for the sentences.

After this the paragraph make a somewhat illogical jump to detection and applications of electrons.

• As in the example above, I would leave the mention of Hawking radiation out of the lead. This a hypthesis that although with massive theoretical support has never been observationally confirmed in any way. This makes it a lot less important than a lot of other things you can say about electrons especially since stellar mass and heavier black holes statistically produce close to zero electrons. I don't care to check the numbers, but don't be surprised of the expect number of electrons created by black holes in the observable universe is less than 1. So, stating this possibility in the lead seems a bit undue.

  If you want you can review this draft. Ruslik_Zero 12:54, 23 August 2009 (UTC)

  That is better but still suffers from many of the above comments. (TimothyRias (talk) 10:05, 24 August 2009 (UTC))

  I've moved it to /draft, so that other editors will feel free to edit it. --___A. di M. 10:00, 24 August 2009 (UTC)

  I made changes to the lead. Ruslik_Zero 11:48, 5 September 2009 (UTC)

History

• Leading subsection ends in a one sentence paragraph.
  • You mean at the end of the first History subsection? I brought that up in the FAC, and RJHall assured me it will be reworded. MasterOfHisOwnDomain (talk) 10:38, 22 August 2009 (UTC)
• In the 'Discovery' section, note that it is only possible to publish result of an experiment note an experiment itself. (As the first sentence of the paragraph about the oil-drop experiment now reads.)
• 'Standard Model' needs to be linked.
• This section IS rather long. It could be condensed by leaving out some of the details (which do wander offtopic at times). It may however be better to create an article History of the electron, and have a more summary style section here. But I don't actually feel that this should be a deal breaker. The main reason that this is longer than the median FA length is that there are so few natural sciences FA. Since FA requires article to cater to the needs of the widest possible audience these FAs tend to become very long.

  Fixed everything except the last one. The History section is itself a summary of the much longer article—History of electromagnetism. To create another historical article would be unreasonable. Ruslik_Zero 12:54, 23 August 2009 (UTC)

  That is maybe where this is going wrong, the current section tends to get side tracked in things in the history of physics in which the electron was only marginally involved. Those this article really need to discuss the history of the atomic model and quantum mechanics. I think that by staying more on focus the history section could be 30% shorter. (TimothyRias (talk) 10:05, 24 August 2009 (UTC))

  I noted nothing myself. So I do not how to fix this. I think all text is necessary. Ruslik_Zero 13:34, 25 August 2009 (UTC)

  I slightly shortened the History section. Ruslik_Zero 08:31, 31 August 2009 (UTC)

Characteristics

Classification

• The phrasing: The electron is an analog of the charged leptons in the second and third generations, the muon and the tauon, respectively, which are identical in charge, spin, and interaction, but are more massive. is a bit awkward. Suggest something along the line: The second and third generation contain charged leptons, the muon and the tauon, which are identical to the electon in charge spin and interactions, but are more massive. The original read like you were defining the properties of the electron in terms of the (more obscure) muon and the tau.
• I'd like to see a source for referring to fermions as a 'family'. The only place I've seen it called that is here on wikipedia. Most of the time the term 'family' in particle physics is used as a synonym for generation. Further more, being a fermion is a property, namely that the particle obeys fermi-dirac statistics.

  Fixed that myself. If there is no need to create new terminology, then it is better not to. (TimothyRias (talk) 10:05, 24 August 2009 (UTC))

• The sentence: This family includes all elementary particles with half-odd integer spin; suggests that only elementary particles can be fermions. Of course, any particle with half-integer total (internal) angular momentum is a fermion (at least those for which the spin-statistics theorem holds.

• The sentence:If the spin of the electron is oriented in the same direction as its momentum, it is called a right-handed spin; otherwise it is left-handed. defines helicity, while the following sentence The left-handed spin component of the electron forms a weak isospin doublet... refers to left-handed chirality. These to are obviously related, but different. With the big difference being that the chirality does not depend on the frame. (which is good as I wouldn't know how a isospin doublet can transform into a singlet through a Lorentz transform.)

  Fixed everything except Family. Family is used here as a synonym of "group". It can be used to describe any type of particles. The word does not carry any special meaning. Ruslik_Zero 12:54, 23 August 2009 (UTC)

  The helicity/chirality issue is still there. (TimothyRias (talk) 16:40, 23 August 2009 (UTC))

  In this case I do not understand what you want. Ruslik_Zero 18:20, 23 August 2009 (UTC)

  Then say so in the first place, and ask for clarification instead stating that you fixed everything. The problem is that there exist two closely related properties of particles the helicity and the chirality. For spin-1/2 particles these both have a left-handed and right-handed component. The helicity is the inner product of the spin and the direction of the momentum of the particle. This is the property that is first described in the last paragraph of the classification section. It depends on the frame of the observer. Chirality is a closely related property (for massless particles they coincide) that depends on the technical transformation properties of the spin-1/2 particle. It is frame independent, and it is the chiral left-handed component of the electron that appear in the the weak isospin doublet together with the left-handed neutrino. Currently the article implies that it is the left-handed helicity component that appears there. This subject is confusing enough as it is, without wikipedia adding further misinformation.(TimothyRias (talk) 09:45, 24 August 2009 (UTC))

  I tried to clarify. Ruslik_Zero 13:30, 25 August 2009 (UTC)

  I've been thinking about this some more and started to wonder why the article is introducing left-handedness and right-handedness at all. The only other place that these terms are mentioned in the article is when discussing the weak interaction in which case it is meant to refer to left-handed chirality. At best explaining these terms adds very little to the article, at worst it confuses the reader. The best may be just to leave the whole paragraph on left/right-handedness out of the article. (TimothyRias (talk) 08:56, 28 August 2009 (UTC))

  I shortened the paragraph about helicity to just one sentence. Ruslik_Zero 08:30, 31 August 2009 (UTC)

  Looks fine. (TimothyRias (talk) 09:00, 31 August 2009 (UTC))

• Isn't it more logical to discuss the stuff about spin in the fundamental properties section? (TimothyRias (talk) 14:03, 26 August 2009 (UTC))

Looking at the other sections I've noticed that there is stuff about spin all over the place. First in the 'classification' section and later again in the 'virtual particles' section, and I think I've seen it somewhere else as well. Anyway it would probably be better have a paragraph or two about the spin of the electron in the fundamentel properties section.(TimothyRias (talk) 12:16, 27 August 2009 (UTC))

I moved spin to the fundamental properties section. Ruslik_Zero 07:09, 28 August 2009 (UTC)

Good.

• This article also suffers from a common misconception on wikipedia on the relation of fermions, spin and the Pauli exclusion principle. The correct relation between these concepts is that: Any particle with 1/2-integer spin, obeys Fermi-Dirac statistics (this is the spin-statistics theorem), part of which is that it obeys the Pauli-exclusion principle. Particles obeying Fermi-Dirac statistics are called fermions. Being a fermion is not a classification (like being a lepton), but a property. (like being a point particle). The natural place of discussing that electrons are fermions would be in the quantum properties section.

  What is the problem here? Ruslik_Zero 08:59, 28 August 2009 (UTC)

  Since each particle is either always a fermion or always a boson, I can't see any real problem with classifying particles as such. In particular, "elementary fermions" is a handy way to refer collectively to quarks and leptons (particles of "matter" according to one definition; not the one I like most but nevertheless in common use). --___A. di M. 10:37, 28 August 2009 (UTC)

  But that is exactly part of the problem. Not all particles are either fermion or boson. In exotic systems you can also have (quasi)particles which are anyons for example. The other part is the article sometimes gave the illusion that being a fermion or boson is defined by the spin. (while in some exotic systems you can have particles with spin-1/2 that are not fermions. Again anyons are an example.) But this has been mostly solved in this article by some of the recent changes. (TimothyRias (talk) 12:06, 28 August 2009 (UTC))

  I don't think anyone would be likely to think that a classification scheme for elementary particles in the Standard Model could also be applied to quasiparticles in graphene sheets and whatnot, but better safe than sorry; the current version as of 18:54, 28 August 2009 (UTC) looks reasonably fine to me. (BTW, this "confusion" predates Wikipedia. Even Landau and Lifshitz claim that by swapping two identical particles the wavefunction must multiply by either +1 or −1 because if you swap them twice you "get back to the original state"; an identical reasoning could imply that any particle has integer spin because if you rotate it by 360° you "get back to the original state", too.) --___A. di M. 18:54, 28 August 2009 (UTC)

  Yeah looks OK now. Wording now sidesteps the issue quite nicely. (TimothyRias (talk) 21:28, 28 August 2009 (UTC))

Fundamental properties

• The first paragraph of this section implies that the electron-to-proton mass ratio is a fundamental constant of the standard model. It is actually quite hard to calculate this ratio exactly from first principles as it involves the poorly understood strong coupling regime of QCD. So, at best it is a derived constant of the standard model. (TimothyRias (talk) 13:39, 28 August 2009 (UTC))
  • The fact is that no-one seems to agree about what "fundamental constant" means. Guys such as John Baez and John Barrow use it to mean "dimensionless constant" (because the numerical value of the fine-structure constant doesn't depend on the choice of units of measurement, unlike the vacuum permittivity, for example); the NIST uses it in a much broader sense, including the Sackur-Tetrode constant at 1 K and 101.325 kPa, the {220} lattice spacing of silicon, or the atomic mass constant. The electron-to-proton mass ratio is "fundamental" in both those senses, but it isn't in senses which would make more sense. (Too bad that no-one seems able to clearly explain which these senses which would make more sense are.) But "derived" isn't much better; I'd just say that it is constant. --___A. di M. 18:45, 28 August 2009 (UTC)
    • I've tweaked the paragraph to avoid talking about fundamental constants at all. (TimothyRias (talk) 09:08, 31 August 2009 (UTC))
• In the last paragraph the sentence: an electron decaying into a neutrino and photon would mean that electric charge is not conserved.[69] seems to be an attempt to explain why the electron cannot decay. To me this choice of particles seems totally random. It also leaves a less informed reader wondering why this should explain that electrons cannot decay. It may actually be easier to just explain this along the lines: 'However, the electron is thought to be stable because it is the lightest electrically charged particle, and any decay process must conserve charge and reduce mass. (OK, this may be worded a bit smoother than this.) Remember that to many readers it may not be immediately clear that decay must always yield lighter particles. Incidentally, if you decide to keep this example note that this is now the first mention of the neutrino in the article. It should either be wikilinked or should be introduced earlier. (TimothyRias (talk) 14:02, 28 August 2009 (UTC))
  • Fixed. --___A. di M. 17:57, 28 August 2009 (UTC)
    • Works for me.(TimothyRias (talk) 09:08, 31 August 2009 (UTC))

Virtual particles

• This section largely deals with things that only tangentially have to do with electrons. Subjects like vacuum polarization and vacuum fluctuations involve basically all (charged) fundamental particles. So I dont think it is necessary to discuss them here. The only stuff that really is about electrons is the remark that the magnetic dipole moment gets a correction at 1-loop order in QED, and similarly the Lamb shift, but those can be dealt simply with a remark at the appropriate values. (TimothyRias (talk) 12:06, 28 August 2009 (UTC))

  I am thinking about this section. Ruslik_Zero 09:15, 31 August 2009 (UTC)

  I slightly shortened this section, but I will probably removed the third paragraph completely. Ruslik_Zero 11:49, 5 September 2009 (UTC)

  Significantly shortened. Ruslik_Zero 11:01, 11 September 2009 (UTC)

Interaction

• Why is there no mention of Thomson scattering?(TimothyRias (talk) 14:50, 28 August 2009 (UTC))

  What is the difference between Thompson and Compton scattering? For free particles they are one and the same. Only in Thompson case it is the visible light that is usually scattered and, therefore the change in energy is small. Ruslik_Zero 15:01, 29 August 2009 (UTC)

  In Thomson scattering their is not transfer of energy. (TimothyRias (talk) 15:30, 29 August 2009 (UTC))

  In Thompson scattering energy is transfered but this transfer is small. So basically there is no such thing as Thompson scattering. Ruslik_Zero 15:41, 29 August 2009 (UTC)

  That is of course true. It is often a good approximation however and there is a lot of literature talking about it, which makes a good reason to mention it. (TimothyRias (talk) 09:14, 31 August 2009 (UTC))

  I added a couple of sentences about Thomson scattering. Ruslik_Zero 19:04, 1 September 2009 (UTC)

• Normally Compton scattering is considered to inelastic rather than elastic, since the photon changes wave length. I know this somewhat of a definition question, but normally Thomson scattering is is considered to elastic, while Compton scattering is not. (TimothyRias (talk) 14:50, 28 August 2009 (UTC))

  I have always thought that a collision is elastic if internal states of the participating particles do not change. Ruslik_Zero 15:01, 29 August 2009 (UTC)

  As I said this somewhat of a definition issue, but in the discussion of a photon scattering of an electron the change of wavelength of the photon is often considered a change in internal state. (The photon changes color). (TimothyRias (talk) 15:30, 29 August 2009 (UTC))

• The outcome of an elastic collision between a photon and a solitary electron is called Compton scattering. I would call normally use the term Compton scattering for the process not the outcome. (TimothyRias (talk) 14:50, 28 August 2009 (UTC))

  Fixed. Ruslik_Zero 15:11, 29 August 2009 (UTC)

• 'Compton wavelength' is used in the paragraph before the one that explains what is and wikilinks it. I think the two paragraphs can be switched without causing major problems. (TimothyRias (talk) 14:50, 28 August 2009 (UTC))

  Paragraphs switched. Ruslik_Zero 15:11, 29 August 2009 (UTC)

• In the formula for the Compton shift the electron mass is given as just m (and in fact without any further note that this is indeed the mass, wait it is in the note but still) in other places in this article (and other places on wikipedia) it is denoted m_e. The later seems preferable. (TimothyRias (talk) 14:50, 28 August 2009 (UTC))
• The article claims that the shift in wavelength is due to a transfer of momentum, this should be energy. Thomson scattering also transfers momentum, but does not cause a wavelength shift. (TimothyRias (talk) 14:50, 28 August 2009 (UTC))

  I clarified that it involves transfer of both momentum and energy. Ruslik_Zero 15:11, 29 August 2009 (UTC)

• I suggest at least wikilinking left-handed to Chirality (physics). If the earlier paragraph about handedness is kept it should be made clear that this is a different kind of handedness. (TimothyRias (talk) 14:50, 28 August 2009 (UTC))

  Linked. Ruslik_Zero 15:11, 29 August 2009 (UTC)

Atoms and Molecules

• Surprisingly this section does not explain that because of the Pauli exclusion principle only two electrons can occupy each orbital, causing the shell structure of the atom, and with it most of chemical and (macro) physical properties. (TimothyRias (talk) 15:06, 28 August 2009 (UTC))

  I added a sentence. Ruslik_Zero 18:31, 29 August 2009 (UTC)

• As a result you get a very strained sentence Pairs of electrons in an atom align their spins in opposite directions, giving them different spin quantum numbers that satisfy the Pauli exclusion principle. that needs to explain this while discussing the relation of angular momentum, spin and magnetic moment. (TimothyRias (talk) 15:06, 28 August 2009 (UTC))

  I rewrote this paragraph. Ruslik_Zero 18:31, 29 August 2009 (UTC)

• Thus the magnetic moments of an atom's paired electrons cancel each other out. Not all electrons in an atom will be paired. Just think about hydrogen (or any other element with odd number of protons). (TimothyRias (talk) 15:06, 28 August 2009 (UTC))

  I clarified this statement. Ruslik_Zero 18:31, 29 August 2009 (UTC)

• Should this section also say something about ions? (TimothyRias (talk) 15:06, 28 August 2009 (UTC))

  I added a sentence. Ruslik_Zero 18:31, 29 August 2009 (UTC)

More to come. (TimothyRias (talk) 09:41, 21 August 2009 (UTC))

Negatron

Searching for Negatron redirects here, but doing a Google search, I found Negatron (album), which ALSO says "Negatron redirects here" at the top of its page. Can someone fix this? Maybe a disambiguation page for negatron? 173.61.86.36 (talk) 23:36, 11 September 2009 (UTC)

Done. Thanks. Materialscientist (talk) 23:47, 11 September 2009 (UTC)

electron

Let the characteristics of the photon which "parents" an electron be preserved in the electron. That is: 1) circumference = wavelength, 2) frequency = frequency, 3) circular velocity = speed of light (i.e., electric fields), and 4) energy = energy.

Electron's radius is the photon wavelength over 2pi. About this radius, the electric fields of the "parent" photon are spiral wrapped. A positron has the opposite sense wrap.

A dough nut is shape equivalent to a sphere. The resultant electric fields around a dough nut are spherical in form and equal in magnitude.

The circularity of the photon (h/2pi)is increased to the circularity of the electron by the additional 2Pi that results from closing the photon on itself.

75.120.152.138 (talk) 20:00, 19 September 2009 (UTC)

Evolutionary context of electron

It might extend the temporal order of the history of electron research to mention its use by electric eels. Though eels did not quantify or describe electrons in language, they identified electrons reliably and separated them according to potential.

Electric eels emerged only about 110 million years ago in fresh water rivers in which low conductivity and conversely high resistance made triboelectric phenomena sensible and usable. The time period predates, though not terribly, the first proto-humans and suggests that electricity was among the factors necessary for a comprehensive concept as Earth's species groped their way to the Moon. —Preceding unsigned comment added by SyntheticET (talk • contribs) 19:23, 16 October 2009 (UTC)

virtual electrons

It says many physicist believe there are virtual electrons. This seems very obscure. If there are virtual electrons, what is determining if the electron is virtual or non-virtual. Also, who accepts this, because I talk to many physicist who have never heard of virtual electrons. —Preceding unsigned comment added by 98.64.245.140 (talk) 00:44, 6 November 2009 (UTC)

Well, I'm not sure what phycists you have been talking to, but any with a decent amount of knowledge should have at least heard of virtual particles, since they are the bread and butter of modern particle physics. Now, one can discuss at length whether virtual particles actually exist or that they are merely an artifact of our perturbation expansion (I'm tempted to say the later), but fact is that you can't do most of the calculations in particle physics without them.

To answer the question of what makes an electron virtual, that is relatively simple. A particle is virtual if E^2-p^2 is not equal to its (rest) mass. (TimothyRias (talk) 08:50, 6 November 2009 (UTC))

References to "point particle"

The article has two references to the electron being a "point particle", one of which is in the second sentence. This is supposed to convey that there is no substructure. Would anyone object to me changing "point particle" to "elementary particle"? "Point particle" is confusing because this term has two meanings: Having no spatial extent, or having no substructure. Only one of these definitions clearly applies to an electron, since an electron wavefunction obviously does have finite spatial extent. On the other hand, "elementary particle" means having no substructure, and is perfectly unambiguous. Moreover, both of the sentences already make it quite explicit that we're saying there's no substructure, so there's no need to worry about people who haven't heard of the term "elementary particle", it's defined clearly by the rest of the sentences.

Sound OK? --Steve (talk) 00:40, 18 November 2009 (UTC)

Steve, I refer you to the article Point particle. This is counterintuitive to me, but there are differences. The electron has mass, charge, and it has spin. It has no radius. So, this is just something to think about, whatever changes you decide to make.Steve Quinn (formerly Ti-30X) (talk) 01:01, 18 November 2009 (UTC)

Also, I want to point out that point particle and elementary particle are two different concepts - (I am repeating myself from WP physics talk - hope you don't mind). Steve Quinn (formerly Ti-30X) (talk) 01:08, 18 November 2009 (UTC)

I think "point particle" is the right term, and more direct; but the article point particle needs to be strengthened to convey exactly what point particle means for a quantum mechanical particle, when the wavefunction as you say does have finite spatial extent; plus how one measures the "pointlikeness" of a point particle (i.e. operationally what does the term mean). Jheald (talk) 01:15, 18 November 2009 (UTC)

Sorry, to add another comment here but, I just noticed the context of "substructure" and "point particle" in the second sentence. Substructure in this context is not related to "point particle". The electron having no substructure means there is no particle or sub-group of particles that it transforms into during a weak interaction. Saying it is a point particle is simply another characteristic of the electron. So in the second sentence two characteristics which help describe the electron are elucidated. However, saying it is an elementary particle is the same as saying it has no substructure. Again I refer everyone to read the article Point particle. Also, there is a discussion that is happening right now, about the article, on that talk page, which may help clarify what a point particle is. Steve Quinn (formerly Ti-30X) (talk) 01:22, 18 November 2009 (UTC)

Jheald, The most likely explanation for its lack of dimension is that it is as you say a wave packet. I suppose wave packet could be seen as merely a packet of electromagnetic radiation, which wouldn't have any spatial dimension. I forgot about this, on the Point particle talk page. It has been awhile since I have thought about it. I just found a book on google books Electron: a Centenary Volume by Michael Springford. I entered "point particle" in the local search function, for the book and the first result so far talks about the direct connection between the electron wave function and its electromagnetic properties. It was Herman Weyl who first understood this? I suppose once I get clarification I can write this into the article. Steve Quinn (formerly Ti-30X) (talk) 02:00, 18 November 2009 (UTC)

This book "Electron: a Centenary Volume" does not appear to be helpful with defining or describing point particle. Also, I am continuing the discussion on "Point particle" over at that article's talk page. Steve Quinn (formerly Ti-30X) (talk) 04:02, 18 November 2009 (UTC)

I made a change to the second sentence. Just to be clear, I believe Jheald that there's probably some sense in which an electron can be thought of as a point particle. But even if that's true, it doesn't need to be said in the second sentence. The very important thing about the electron that does need to be said in the second sentence is that the electron isn't made of even smaller particles, there's nothing inside it, it's the bottom level, unlike everything in the everyday world. This is a very important point that every reader should know immediately. Whether an electron is a point particle in a certain sense, even though it never exists at just one point, is worth figuring out but doesn't need to be said in the opening section, and certainly not in the second sentence, in my opinion. :-) --Steve (talk) 06:31, 19 November 2009 (UTC)

Zitterbewegung ?

The text mentions virtual photons making the electron dance around. the link says its due to positive and negative energy states of the Dirac equation. And, particles can have spin without charge, so how can this be said to cause the spin and magnetic moments?

If this is supposed to be just a classical way to view it (from the 1950s) that should be made clearer.

I'll leave it to a working expert in the field to edit. But I hope it gets some attention before the Front Page day.

—Długosz (talk) 00:08, 19 November 2009 (UTC)

Ugly formatting

Headbomb reverted some of my edits with the comment "Unicode fractions are ugly." Well, oversized split-level fractions that don't sit properly on the baseline "are ugly". It's particularly bad with "spin-1⁄2" where the fraction is half again the size of the regular letters in the word. In this context, the ½ is a single simple concept and shouldn't stand out of the page more any any other part of the sentence.

So does that reversion constitute an act of edit war? I'll open it for discussion here rather than re-applying my original change. Just saying "is ugly" for someone else's intentional improvements is rather rude, at the very least.

Also, the formula that shows as a tiny single-char √ symbol followed by a 3 with an overline, which is naturally above the character cell and does not line up with the radical char, is just plain wrong. As much as Math tags have their own issues with text size zooming, this approximation is not semantically correct for page scanners and accessibility, and looks goofy.

—Długosz (talk)

Single reversions never consist of edit wars. Concerning 1⁄2 vs. ½, the former is much more readable. I'm neutral on the sqrt thing, although I favour any html-based solution (such as &sqrt;3/2&bsp;ħ) over inline math tags. Headbomb {^ταλκ_{κοντριβς} – WP Physics} 20:46, 19 November 2009 (UTC)

Are this Unicode symbols correctly displayed by all browsers? Ruslik_Zero 06:21, 20 November 2009 (UTC)

WP:MOSNUM says not to use unicode fractions because they cause trouble for those using screen readers, and they are generally less readable. Dabomb87 (talk) 00:05, 21 November 2009 (UTC)

Sorry, I got confused....it's definitely a point particle

Original post removed due to author embarrassment.

That information is incorrect. Because it has no physical size, it is considered a point particle. It is a "structureless, point-like particle". It is called a point particle because it has no dimensions, it has no spatial extent. See page 70 in this book for one source:

Haken,, H. (2000-10). The physics of atoms and quanta: introduction to experiments and theory. Springer-Verlag New York, LLC. p. 70. ISBN 3540672745. {{cite book}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: extra punctuation (link)

I could probably come up with other sources. Steve Quinn (formerly Ti-30X) (talk) 06:45, 21 November 2009 (UTC)

Style?

"half integer value of ½"; ugh! Peter jackson (talk) 11:12, 21 November 2009 (UTC)

Physicists believe that

The paragraph on Virtual Particles start with "Physicists believe that...". This phrase suggests that what coming up is somehow more far fetched than the rest of the article, whereas virtual particles are a general feature of QFT's. Virtual particles are by definition to be measured indirectly, so it's not a question of believe. It says "all physicists", as if some non-physicists where the ones who came up with critics on that viewpoint. I mean the whole article is on what physicists "believe" so what does that mean anyway? (212.186.99.222 (talk) 12:56, 21 November 2009 (UTC)).

What should come first?

Congratulations for making this a featured article (without my help). However it seems to me to be directed too much toward specialists, or perhaps overestimates the average person's knowledge. I think the fact that electrons account for most of the properties of matter that we observe (and are) in everyday life should come before how they fit into the particle physics classification system. How about starting more like: "The motion of electrons and their electric [and magnetic] fields cause the majority of the events of everyday life. Since the outsides of atoms consist of electrons, they dominate the way atoms stick together to form molecules and matter." Maybe after the first sentence. Or how about somewhere early on: "Nearly all of chemistry, for example, is the result of the way electrons are shared between atoms."

I read that beginning physics students view physics as a set of unrelated formulas to be memorized! So we should start by telling how electrons fit into the rest of science and life. I did once clearly experience the ratio of the mass of the electron to that of the proton, when I had to increase the magnetic field of a cyclotron slightly when I switched between accelerating positive and negative ions, in opposite directions. But most of my experience with electrons has to do with my own body and the matter around me where the effect of the electron mass is only useful to those who know how to calculate the de Broglie wavelength. Or show how to use the mass: "Because an electron has a mass that is approximately 1/1836 that of the proton, electron matter waves have much longer wavelengths than those of nuclei, so that the outsides of atoms consist of electrons and they dominate the way atoms stick together to form matter." That is a long sentence, but what use is it to know the mass without it? David R. Ingham (talk) 22:13, 21 November 2009 (UTC)

Amber and lightning man's earliest experience of electricity?

"The ancient Greeks noticed that amber attracted small objects when rubbed with fur; apart from lightning, this phenomenon was man's earliest known experience of electricity."

What about shocks from electric eels? According to this they were even used for early treatments for headaches and this talks about them being used in Ethiopia to drive out devils, although it wasn't reported until the 16th century.

I also have a problem with the following sentence in the lead which, in fact, isn't really a complete sentence:

"However, this duality is more easily demonstrated in experiments with electrons, due to their tiny mass."

More easily demonstrated than in experiments with what - light or other particles?

I would also agree with the point above about the lead being a bit difficult for the non-expert. The lead should be there to draw in the non-specialist and I think introducing concepts like "The intrinsic angular momentum (spin) of the electron is a half integer value of ħ" so early is off-putting. Richerman (talk) 14:02, 23 November 2009 (UTC)

Maybe it should say "tiny but non-zero mass". Light, with zero rest mass, shows wave properties more easily, but its particle properties weren't noticed until almost the 20th century.David R. Ingham (talk) 17:49, 1 December 2009 (UTC)

The phrase I had problems with was "more easily demonstrated". I tried "most easily demonstrated" but that sounded clumsy, so I've changed it to "best demonstrated" which makes more sense grammatically. If the statement isn't actually true then it should be changed, but the lead should summarise what it says in the article, so you may need to also add something about that elsewhere. Richerman (talk) 00:17, 3 December 2009 (UTC)

About the Sokolov-Ternov effect

The note 9 says that the spins of the electrons in a storage ring will be aligned. OK. But it suggests that they will be aligned with the momentum. That is clearly wrong. They get aligned with the magnetic field. Just read the article Sokolov-Ternov effect to be convinced. —Preceding unsigned comment added by Trassiorf (talk • contribs) 11:04, 1 March 2010 (UTC)

Charge of the electron

"The electron's charge was more carefully measured by the American physicist Robert Millikan in his oil-drop experiment of 1909, the results of which he published in 1911." I have old physics books, that state the electron charge is 1.1 *10^-19 C . So what changed in how the electron charged is measured now (it being 1.6*10^19C) and then during the Millikan experiement. I want to make another point that this article should talk about positive and negative electricity, because that plays a large role in the history of the electron.

Criticism

Many physicist did not agree with the electron hypothysis, including albert einstien, and the so called discoverers. That being JJ Thomson himself. JJ Thomson even wrote a book about electrodynamics and electrons are not mentioned. Also Rutherfords experiment is very similar to Thomson. There is no analytical evidence, that the atom is composed of electrons surrounded by protons, and it was Rutherford who actually discovered the electron. But in any case I would like to state the number of physics of the time who disagreeed that electrons even exist at all!!: Rutherford Thomson Einstein Heaviside Tesla ... Actually for the most part ALL scientist prior to about 1930-1940 were skeptical to the existence of the electron. It was only after the atomic bomb, and secrecy and physicist being hanged for treason, were people completely unable to question it, but rule by tyranny is not scientific agreement! The next generation was brought up under the fear of communism, but now communism is over so why can't we ask again if the electron exist? 71.57.136.104 (talk) 14:36, 15 March 2010 (UTC)

You are sorely misinformed. Dauto (talk) 06:44, 3 May 2010 (UTC)

If you read the original paper Thomson makes it absolutely clear that the entire point of the experiments he is reporting is to demonstrate that there exists a subatomic particle which carries the negative charge, and has a small but measurable mass. Thomson was at pains to exclude other conclusions. Can you cite a publication by any of the scientists in the time period you claim where their words demonstrate that they were "skeptical to the existence of the electron"? I think you cannot. Nick Beeson (talk) 17:39, 6 July 2010 (UTC)

Compton scattering: elastic or inelastic?

Re. the recent edit and revert, IIRC I've heard that in Compton scattering the change in wavelength of the photon is "conventionally" considered a change in internal state, so the collision is considered to be inelastic. The Compton scattering article also calls it inelastic, but I have no source at hand at the moment, so I'm not going to re-instate the "inelastic" in this article for now. ― ___A._di_M. (formerly Army1987) 18:08, 11 April 2010 (UTC)

In some publications it is clearly called elastic [2] and [3]. Ruslik_Zero 19:01, 11 April 2010 (UTC)

On the Compton scattering page it is called inelastic. Daniel.Cardenas (talk) 21:13, 11 April 2010 (UTC)

It is an elastic "collision" (total energy is conserved), but it is inelastic scattering of photons (they are losing energy). /Pieter Kuiper (talk) 21:47, 11 April 2010 (UTC)

Was my teacher right on this ?

I once had a physic teacher who said that all electrons are just 1 particle, as it had the same mass he concluded it is only everywhere. Its a kind bizarre but.. well quantum-physics do allow of objects to be at multiple places at once. Now i can understand that his view is not a regular view in physics, but the striking logic seamed so correct, i mean why aren't there electrons who are of slightly different mass like + - 0.00000001% it doesn't happen. So i tought maybe he had a point, now i'm years older not on school anymore and i wonder if he was unique in his idea, or that there is a group op physicians who have the same idea, and call it "xxxx" well i don't know how it is called. 82.217.115.160 (talk) 22:33, 11 May 2010 (UTC) 82.217.115.160 (talk)

This a well known idea proposed by Feynman and Wheeler, see one-electron universe. It is based on the fact that anti-particles can be viewed as particles moving backwards in time. You could thus imagine all electrons and positrons being part of one worldline weaving back and forward through time. It would require there to be exactly as much antimatter as there is matter, which is not consistent with observations. TimothyRias (talk) 09:10, 12 May 2010 (UTC)

Cathode Rays

I was puzzled at the lack of a citation for the original paper by J. J. Thomson. I had no trouble finding a copy posted online, and with it the correct original citation. I placed it into the article at what I consider the appropriate places. This citation has a url to a facsimile of the original paper. The original paper was published in 1897 so is definitely in the public domain. Nick Beeson (talk) 17:58, 6 July 2010 (UTC)

electro, magnetic fields for photon electron and nuclei is it in there genes

It will ever astonish me that photon electron and nuclei all have in common: electric and magnetic fields, and gamma rays (charged photons) produces electrons and positrons in a process called pair production, and that photon and electron "cause" to produce each other Is it in there "genes"?

could it be, when the electron go to deeper orbital next the Nuclei the vacuum expile a photon (a quantity, a piece of,from vacuum energy) in the opposite direction of the electron movement to observe the electric and magnetic and spacetime curvature energy conservation. this way in contradictory to the commoen belive that elctron it self acutlly produces the photon; the electron cause the mediume (i.e. vacuum, vacuum energy) to expile a photon (quantity) since according to Enistein's e = m c^2 space have curverture near mass's and that space curvature apply, may be, that is a denser or it is of a higher energy location in space when it is near the nuclei of an atom than it is further away form it, and that all object have Schwarzschild radius.--e:Y,?:G 17:11, 11 October 2010 (UTC) —Preceding unsigned comment added by E:Y,?:G (talk • contribs) --e:Y,?:G 17:33, 11 October 2010 (UTC)

Introduction too long and unorganized

I think the introduction is too long and inappropriate, it does not point out the relevance of the subject. The fact that the electron is a component of atoms, and that it is the main responsible of almost all properties of matter, chemical, electrical, optical, thermal, mechanical (except mass)..., is given as a detail, after having spoken of what happens if it collides with a positron (which is said twice, in the lead section). Also, the discussion wave-particle, or the details on who and when made theories on it can be posponed into the body of the article.

Perhaps the subject should be divided quite sharply in two: the "low energy" part (electrons in matter); and the "high energy" part (the elementary particle and its interactions with other particles). —Preceding unsigned comment added by GianniG46 (talk • contribs) 14:59, 19 October 2010 (UTC)

I agree with you. I've reorganised it into a more logical order (roughly speaking 1 paragraph of its significance in classical physics, 1 paragraph of particle physics, 1 paragraph history, 1 paragraph cosmology and technological applications), trying to keep the most general 'context' stuff near the beginning for general readers. I tried to improve the prose to make it more readable. It was also really long - I removed one sentence about how an electron moves in a magnetic field, as that's just information about charged particles and not really specific to electrons. I also removed some sentences about the positron: this is the electron article, surely the place for a definition of the positron is the lead section of the positron article.--Hermajesty21 (talk) 00:07, 10 December 2010 (UTC)

I have reverted Hermajesty21 mostly because of undue focus on topics which are only indirectly related to electron - the 2nd/3rd sentences for example. Materialscientist (talk) 00:15, 10 December 2010 (UTC)

I agree with MaterialScientist. The previous version was better. This is about the electron, not the atom, and the "rewritten" version takes the focus out of what the article is about. That being said, I agree that the lead, especially the first paragraph, should establish more firmly that electrons are components of atoms (see quark for an example of this "establishement" of where things can be found)).Headbomb {talk / contribs / physics / books} 00:13, 10 December 2010 (UTC)

I see your point, but I still think that the current version has its problems too- apart from the overemphasis on atoms, what do you think of the other changes in my edit? I have got to go now, but will try to discuss more tomorrow.--Hermajesty21 (talk) 00:20, 10 December 2010 (UTC)

Article leads should be as accessible as possible to the general reader. If someone asks you what electrons are, one of the first things you'd explain is that they are one of the particles that make up atoms. It just doesn't make sense to leave this till the end of the third paragraph.

I also feel that the current lead doesn't really flow, much of it reads like a collection of facts stuck together. I tried to improve the prose so that it's more readable. I recognize that my version should be improved by putting less focus on the electron's role in the atom, but could you read through my edit and discuss what you think of my other changes?--Hermajesty21 (talk) 22:06, 10 December 2010 (UTC)

I think Hermajesty21's edit could be a start point. Perhaps simplifying the first sentences and modifying syntax to make the electron (instead of the atom) to be the subject could already help. But, anyway, the importance of electrons in all properties of matter cannot be left out. The history, instead, can be simplified: it is sufficient to speak only of Thomson in the lead, the other facts are already reported in the body of the article. --GianniG46 (talk) 23:01, 10 December 2010 (UTC)

I looked at the lead for quark as suggested by Headbomb: it seems a good example of what to aim for, covering the most important properties of quarks in very accessible prose. Here is a new version, hopefully taking on board GianniG46's suggestion about the first few sentences. Do you think it solves any problems of the current lead? Feel free to change it around and post any improvements. (Note: It looks a lot shorter posted here than in the article, because of the lack of info box)--Hermajesty21 (talk) 15:10, 11 December 2010 (UTC)

It needs a good spitshine, but it's definitely a step in the right direction. I didn't look at it in details, but the "what & where & importance / properties / history / origins & applications " seems like a winning structure. Headbomb {talk / contribs / physics / books} 11:04, 17 December 2010 (UTC)

Whatever shortcomings the Hermajesty21's proposed lead (below) may have, I feel it is more than a step in the right direction. I would support replacing the lead with it now and making incremental changes in place. The structure of the current intro may have been ok for the muon or the tao-neutrino, but the electron plays a major role in everyday phenomena. The general reader doesn't need to learn about it's spin and anti-particle so early. Spiel496 (talk) 16:07, 30 December 2010 (UTC)

A possible new lead

The electron is a subatomic particle carrying a negative electric charge. Electrons orbit nuclei of protons and neutrons to make up atoms, bound together by the electromagnetic force. The mass of an electon is approximately 1/1836 that of a proton, hence electrons contribute less than 0.06% of the mass of an atom. In chemistry, the exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding. Electrons also play an essential role in electricity, magnetism, and thermal conductivity.

The electron has no known components or substructure, so is generally believed to be an elementary particle. The intrinsic angular momentum (spin) of the electron is a half (in units of ħ), making it a fermion. In the Standard Model of particle physics, electrons belong to the first generation of the lepton particle family, and they participate in gravitational, electromagnetic and weak interactions, but not the strong interaction.

The concept of an indivisible amount of electric charge was theorized to explain the chemical properties of atoms, beginning in 1838 by British natural philosopher Richard Laming; the name electron was introduced for this charge in 1894 by Irish physicist George Johnstone Stoney. The electron was identified as a particle in 1897 by J. J. Thomson and his team of British physicists. Quantum mechanics, developed in the early 20th century, predicts that electrons, like all matter, have properties of both particles and waves. Experiments to demonstrate this work best with electrons, due to their tiny mass. Apart from photons, electrons were the first particle whose wave-like nature was demonstrated, by electron diffraction experiments in 1927.

According to theory, most electrons in the universe were created in the big bang, but they may also be created through beta decay of radioactive isotopes and in high-energy collisions, for instance when cosmic rays enter the atmosphere. Electrons may be destroyed through annihilation with positrons, their antiparticle, and may be absorbed during nucleosynthesis in stars. Laboratory instruments are capable of containing and observing individual electrons as well as electron plasma, whereas dedicated telescopes can detect electron plasma in outer space. Electrons have many applications, including welding, cathode ray tubes, electron microscopes, radiation therapy, lasers and particle accelerators.

Depiction from File:Hydrogen Density Plots.png

This plot is a bit misleading and needs to be corrected. The plot is obviously a probability distribution (as subtitled) not a wave-function plot as titled. Title and Subtitles should be reversed. Furthermore, the gradient bar ranging from minus (-) to positive (+) is very misleading and confusing. A probability cannot be negative. It appears the intended range is zero (0) to one (1) [from black through violet, orange, and yellow to white]. It's a very nice depiction that is just in need of a little polishing. As it stands it's misleading students who stumble onto this page. Pnictogen (talk) 16:02, 7 December 2010 (UTC)

Names and citations

Back when it ran for FA, I tried uniformizing references, but this somehow was met with resistance from whomever nominated the article [or maybe someone else, not really important]. So now I've gotten to clean everything up except the names in the citations, which was the contention point. The guiding principle of the WP:MoS is articles I need to be self-consistent. Currently, we have these styles use for names

• Smith, John Samuel
• Smith, John S.
• Smith, J. S.
• Smith, J.S.
• Smith, J S
• Smith, JS

We should pick one and stick with it. The first and second options are not viable because the first and middle name of several of these authors will be extremely hard to track down, and will be extremely tedious to do so when possible. Which leaves us with the last four. So I'll switch everything to "Smith, J.S." as it is the closest in style to quark, another FA, which uses "J.S. Smith". If people would rather have "Smith, JS" or others, it would be trivial to switch to them (with AWB). Headbomb {talk / contribs / physics / books} 15:10, 17 December 2010 (UTC)

• That's the style I'd prefer too, closely followed by “Smith, John S.”. A. di M. (talk) 15:35, 17 December 2010 (UTC)
  • Done. I also trimmed any citations with 4 or more authors to Smith, J.S.; et al. Headbomb {talk / contribs / physics / books} 15:45, 17 December 2010 (UTC)

    Per Wikipedia:Citing sources/example style: "A good guideline is to list author names as they are written in the original article/book, without further abbreviation. The APA guidelines recommend abbreviating first names to initial letters instead, but since Wikipedia has no shortage of space, you need not abbreviate names." I see no consensus regarding whether the article should use the same name style for all authors.

    Going through an article and changing reference names into initials is removing information and I do not see a benefit. There is also not a consensus in the style guide to do so.—RJH (talk)

    • • • I have never seen a style guide on Wikipedia (or elsewhere for that matter) which said that citations should be presented inconstantly, and I've seen just about every on style there is to see (and BTW, Wikipedia:Citing sources/example style is not part of the manual of style, it's an example guide that shows what can be done. This works in certain articles, usually those primarily citing books. This does not work here). The core principle of WP:MOS and all other style guides are that articles, including citations, are consistent within themselves. You will not find one manual of style (either general, or specialist, or a high-quality journal's house style) which allows for some citations to be in the "Smith, John" style, while others in the "Smith, J." style. It is also not because the information exists that we need to include it. For example, we exclude ISSN and journal publishers from journal citations. We truncate long lists of authors (the exact threshold depends on the editor/style guide followed). Including full names in citation is both a nightmare for maintenance (the second you cite an article where you can't find an author's first name, you make your article inconsistent and need to either switch styles, or [even worse] find another citation just so you can maintain stylistic consistency). And lastly, per WP:CITEVAR, articles should be streamline according to established usage. In this article, it was "Smith, J.S." or possibly (I didn't bother checking for spaces) "Smith, J. S."m so that's what got picked up in the end. Headbomb {talk / contribs / physics / books} 17:27, 15 March 2011 (UTC)

Personally, I think you are int interpreting WP:CITEVAR correctly. It says, "Do not change the citation style used in an article merely for personal preference or cosmetic reasons. If you think the existing citation system is inappropriate for the specific needs of the article, gain consensus for a change on the talk page before changing it." The standard is about the general styles of the citation; whether harvard style vs. something else. It does not mention the particulars of the author naming. You also did not discuss this on the talk page before you began making personal preference style changes.

I began a general discussion here. I would like to see this standardized.—RJH (talk) 17:46, 15 March 2011 (UTC)

Leptogenesis

A passages currently reads

For reasons that remain uncertain, during the process of leptogenesis there was an excess in the number of electrons over positrons.

However, further inspection of the source raises a few question. While several articles in Progress in Physics are great, as a whole the journal is seen with a suspicious eye by many people as it seems it publishes a bit more "weird" results than would be expected. FA criteria 1(c) says "Claims are verifiable against high-quality reliable sources". While I'd never "purge" Progress in Physics from all Wikipedia articles, I think it should be fairly easy to find a better source for this. Especially if you read the article, it doesn't seem to discuss this at great length, it's simply a list of "unsolved" issues in particle physics, with very little information about what exactly is the problem, or why it is a problem. The only things related to leptogenesis is "11. SM does not clarify the origin of its gauge group SU(3)xSU(2)xU(1) and why quarks and lepton occur as representations of this group;", although there is also "2. The problem of symmetry and antimatter observation. This could be one of the biggest puzzle in cosmology: If it’s true according to theoretical physics (Dirac equation etc.) that there should be equal amounts of matter and antimatter in the universe, then why our observation only display vast amounts of matter and very little antimatter?" So could we find a better source for this? I mean this one is 2007 publication which still considers the "missing solar neutrinos" to be a problem while it had been solved since the early 2000s. Or list as a problem "Muonium problem. Muonium is atom consisting of muon and electron, discovered by a team led by Vernon Hughes in 1960 [19]. What is the dynamics behind muonium observation?" Surely there are books or reviews tackling the leptogenesis issue better than this one? Headbomb {talk / contribs / physics / books} 22:34, 18 January 2011 (UTC)

Fractional version of mass

I have some issues with the fractional version of mass in the Infobox for electron and positron. Please read more about it on the positron talk page.

    — SkyLined (talk) 07:18, 3 August 2011 (UTC)

MeV mass wrong.

Currently the mass of the electron is given as 0.510998928(11) MeV/c2, however, this is wrong. It should be the rest energy is 0.510998928(11) MeV[7], which is what the source and other places online actually say. Basically, there is a stray 1/c^2 that if you multiplied by, you would get a rest energy of a factor of 9*10¹⁶ too high. This problem also occurs in the proton article as well and may be in other articles. 152.19.144.186 (talk) 18:45, 22 September 2011 (UTC)

Nope. See electron volt#Mass.
― A. di M._plé^dréachtaí 18:59, 22 September 2011 (UTC)

It seems to be a notation issue then. I think the MeV/c² notation is rather misleading because anyone trying to find the rest energy who makes the easily made errant assumption about how the notation works is going to assume you find the rest energy by multiplying that number MeV/c² by c². I don't know how common or "set in" writing mass as MeV/c² is, but it would be a lot clearer if you wrote it (0.511 MeV)/c². The parentheses make it clear that the units of 0.511 are MeV, not MeV/c² 152.19.144.186 (talk) 19:47, 22 September 2011 (UTC)

Those parenthesis are not necessary. MeV/c² is a correct unit. Dauto (talk)

We don't want the article to be confusing or misleading. However, I'm not understanding 152.19.144.186's point. The convention in Physics is to treat units like algebraic terms. Your suggestion with the parentheses is like saying "(a*b)/c is more clear than a*b/c" -- they look the same.

And the "errant assumption" you talk about doesn't seem so errant. One should multiply the mass by c² to get the rest energy. Rest energy = mass * c² = (0.511 MeV/c²) * c² = 0.511 MeV. Right? Can you come up with an example where one would get the wrong numerical result because of this notation? Spiel496 (talk) 00:35, 23 September 2011 (UTC)

Electron is missing gravitational mass?

I have just found extremely surprising PRL paper from 1967: F. C. Witteborn and W. M. Fairbank, "Experimental Comparison of the Gravitational Force on Freely Falling Electrons and Metallic Electrons": http://prl.aps.org/abstract/PRL/v19/i18/p1049_1 in which they have measured gravitational mass of electron while free falling and it occurred it is nearly zero. Since there is even planned CERN measurement of gravitational mass of antimatter ( http://aegis.web.cern.ch/aegis/home.html ), I believed these electron results were widely confirmed while these 44 years, but surprisingly I couldn't find anything (?) Anyway, I believe it really should be mentioned in the article.89.78.183.53 (talk) 07:38, 19 October 2011 (UTC)

They also published a Nature article on that in 1968 doi:10.1038/220436a0 which received only 30 citations on Web of Science so far (the PRL article has 130 citations). Materialscientist (talk) 07:47, 19 October 2011 (UTC)

I apology, the paper explains the lack of gravitational acceleration: caused by gravitation gradient of surface electron density, create electric field precisely canceling gravitational acceleration ( http://prola.aps.org/abstract/PR/v151/i4/p1067_1 ). If this explanation is complete, we still don't really know the gravitational mass of electron. 89.78.183.53 (talk) 14:23, 19 October 2011 (UTC)