View source for Talk:Electron/Archive 3

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==Density function image==
I've made a newer version of the density function image, i think it should replace the old one.
[[Image:Hydrogen_Density_Plots.png|right|thumb|150px|''Hydrogen'']]
Yey or ney?
<small><span style="font-size: smaller;" class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:PoorLeno|PoorLeno]] ([[User talk:PoorLeno|talk]] • [[Special:Contributions/PoorLeno|contribs]]) 22:49, 16 August 2008</span><!-- Template:Unsigned --></small>
:I'm not completely convinced that a Hydrogen electron density function image is the best illustration for an article on the electron. It requires too much explanation to make sense, and I think something clearer is needed. But your illustration probably would be great for the [[hydrogen]] article.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 20:20, 18 September 2008 (UTC)

== Introduction ==

Can't we do better than "a very small mass": small compared to what? Also in, "The electron is a spin-1/2 lepton which participates in electromagnetic interactions and is defined by convention to have a charge of −1", why just mention the electromagnetic interaction? Shouldn't we say "...which may interact with other fundamental particles through gravitation and the electroweak interaction (electromagnetism and weak interaction) depending on the specific particle it is interacting with". Lastly: UNITS! -1 of what?
[[User:Krea|Krea]] 20:35, 15 July 2006 (UTC)

::The charge is in atomic units, of course. I've added that to the introduction. [[User:Itub|Itub]] 13:03, 16 July 2006 (UTC)

:No units are necessary. The charge of the electron ''defines'' the units. Only the electromagnetic charge was mentioned because the original wording says "lepton which participates in electromagnetic interactions"; that is, as opposed to neutrinos which are "leptons which ''do not'' participate...". -- [[User:Xerxes314|Xerxes]] 18:49, 17 July 2006 (UTC)

::Surely stating that it is charged relates to the fact it participates in EM interactions. We have said lepton with no more explanation, why not put it as having an electric charge which would say all this.[[User:Jameskeates|Jameskeates]] 10:16, 17 August 2006 (UTC)

== Electrinos ==

A few years back, someone proposed that you could split an electron in half if you zapped it with light while it was suspended in liquid helium. Have any experiments of this nature been attempted so far?

:I think it should be referenced in this article, or perhaps one could be written about electrinos themselves. [http://www.sciencenews.org/articles/20000930/note13.asp Electrino Article from 2000]...     --[[User:Tyco.skinner|HantaVirus]] 13:49, 24 July 2006 (UTC)

:I think that it should not be referenced in this article, because electrinos are either total crap or a non-physical abstraction.  Given that [http://www.slac.stanford.edu/spires/find/hep/www?AUTHOR=&TITLE=electrino a SPIRES search] turns up zero results for "electrino" while the same search for "electron" yields 15113 hits (and similarly at [http://portal.isiknowledge.com/ ISI Web of Knowledge], even if it is not total crap, it clearly isn't of much interest to physicists. --[[User:Strait|Strait]] 22:06, 24 July 2006 (UTC)

:You thinking that it is crap does not detract from the fact that material on the subject exists (beyond the aforementioned article [http://www.springerlink.com/(nxtnr1qcv4g5a5vm5seeqven)/app/home/contribution.asp?referrer=parent&backto=issue,14,14;journal,295,334;linkingpublicationresults,1:101591,1] [http://www.springerlink.com/(e2v2k3jgaktqpjabclcyyp55)/app/home/contribution.asp?referrer=parent&backto=issue,1,9;journal,59,433;linkingpublicationresults,1:104917,1]). As part of [[Wikipedia:Neutral point of view|NPOV]], attention is supposedly to be paid due to all views, however unlikely the phenomena that they describe may be. There are a slew of articles devoted to classically irrational concepts in existence on Wikipedia, and they remain because it is biased to presume them to be invaluable simply because they have yet to be proven or are not rigorously studied by physicists. --[[User:Tyco.skinner|HantaVirus]] 13:53, 26 July 2006 (UTC)

::Assuming enough people have written on the topic of electrinos for them to be considered [[Wikipedia:Notable|Notable], it's one thing to have an article on electrinos which acknowledges that some people believe in them while also acknowledging that the vast majority of physicists do not accept the theory as correct.  It's another thing to include this discussion in the main article on electrons, because that makes it seem like electrinos are a mainstream idea, when, in fact, they are incredibly obscure.  -- [[User:Strait|Strait]] 15:40, 26 July 2006 (UTC)

:::Should we think the same about Matter Creation?
[[User:Bvcrist|Bvcrist]] 05:08, 12 August 2006 (UTC)

== single electron ==

i read somewhere maybe ten years ago that there's a theory that there is only one electron in the universe, and that it moves *really* fast, so it *appears* to be everywhere at the same time. does anybody know where this theory originated, or provide a link? thx --[[User:Sarefo|Sarefo]] 13:10, 15 August 2006 (UTC)

:[http://www.answers.com/topic/one-electron-universe]...[http://www.google.com google] is your friend. --[[User:Tyco.skinner|HantaVirus]] 17:03, 15 August 2006 (UTC)

::[[One electron universe]]... Wikipedia is your friend! [[User:Melchoir|Melchoir]] 23:16, 15 August 2006 (UTC)

== Why do they stay in orbit? ==

Given that opposite charges attract, what stops an electron from crashing into the positively-charged atomic nucleus?  (I presume it is not analogous to a planet orbiting a star, since electromagnetic force is so much stronger than gravity, and anyway an electron isn't really a particle at all.)  [[User:Widsith|Widsith]] 09:16, 24 September 2007 (UTC)
:I was wondering the same thing...  If anyone answers (this or the question below), please tell me. [[User:76.188.26.92|76.188.26.92]] 21:47, 26 October 2007 (UTC)
::It's kind of analogous. A planet doesn't fall into a star because it has enough energy to keep going round, and the same is true for an electron in an atom. [[Special:Contributions/81.174.226.229|81.174.226.229]] ([[User talk:81.174.226.229|talk]]) 09:37, 7 February 2008 (UTC)
:::The unified equasion solves this[[Special:Contributions/98.117.140.24|98.117.140.24]] ([[User talk:98.117.140.24|talk]]) 05:01, 12 March 2009 (UTC)
Sometimes they do fall in. It's called [[electron capture]].  <small>—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/76.5.246.46|76.5.246.46]] ([[User talk:76.5.246.46|talk]]) 18:10, 3 July 2008 (UTC)</small><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->
In Science there only 2 (emphasize 2) categories or sets of information and they are not mutually exclusive sets or categories.  One catgory may be true enough to be considered as factual (under the considered conditions) and the other is opinion. And I propose to you that whereas electrons are a constituent of the atom, which I consider to be a fact, the idea of an electron orbit or orbital is not a fact, but only an opinion.WFPM[[Special:Contributions/70.242.160.149|70.242.160.149]] ([[User talk:70.242.160.149|talk]]) 20:16, 15 August 2008 (UTC)See [[Talk:Nuclear model]]WFPM[[User:WFPM|WFPM]] ([[User talk:WFPM|talk]]) 20:27, 15 August 2008 (UTC)WFPM[[User:WFPM|WFPM]] ([[User talk:WFPM|talk]]) 20:49, 15 August 2008 (UTC)

In a classical point of view the electron should crash into the nucleus. The electron motion is an accelerated one, therefore it has to emitt electromagnetic radiation. Due to this energy loss the electron would crash into the nucleus. So Bohr postulated there have to be stable orbits, characterized by the momentum or orbital momentum of the electron. One can imagine that the stable orbit has to be a multiple of the deBroglie wavelength of the electron, therefore the electron interferes with itself constructively.

The elcetron capture is also a quantum mechanical process, this is due to the high probability of a s-electron at the nucleus site.  <span style="font-size: smaller;" class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/87.185.165.10|87.185.165.10]] ([[User talk:87.185.165.10|talk]]) 12:47, 22 November 2008 (UTC)</span><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->

== Too much detail? ==

I'd like to propose that the three paragraphs in the history section be removed because they are too detailed and do not add significantly to the history of the electron (which I think should be at a high level). They are the following:

:Thomson's 1906 Nobel Prize lecture can be found at http://nobelprize.org/nobel_prizes/physics/laureates/1906/thomson-lecture.html.  He notes that prior to his work: (1) the (negatively charged) cathode was known to be the source of the cathode rays; (2) the cathode rays were known to have the particle-like property of charge; (3) were deflected by a magnetic field like a negatively charged particle; (4) had the wave-like property of being able to penetrate thin metal foils; (5) had not yet been subject to deflection by an electric field.

:Thomson succeeded in causing electric deflection because his cathode ray tubes were sufficiently evacuated that they developed only a low density of ions (produced by collisions of the cathode rays with the gas remaining in the tube).  Their ion densities were low enough that the gas was a poor conductor, unlike the tubes of previous workers, where the ion density was high enough that the ions could screen out the [[electric field]].  He found that the cathode rays (which he called corpuscles) were deflected by an electric field in the same direction as negatively charged particles would deflect.  With the electrons moving along, say, the x-direction, the electric field E pointing along the y-direction, and the magnetic field B pointing along the z-direction, by adjusting the ratio of the magnetic field B to the electric field E he found that the cathode rays moved in a nearly straight line, an indication of a nearly uniform velocity v=E/B for the cathode rays emitted by the cathode.  He then removed the magnetic field and measured the deflection of the cathode rays, and from this determined the charge-to-mass ratio e/m for the cathode rays.  He writes: "however the cathode rays are produced, we always get the same value of e/m for all the particles in the rays. We may...produce great changes in the velocity of the particles, but unless the velocity of the particles becomes so great that they are moving nearly as fast as light, when other considerations have to be taken into account, the value of e/m is constant. The value of e/m is not merely independent of the velocity...it is independent of the kind of electrodes we use and also of the kind of gas in the tube."

:Thomson notes that "corpuscles" are emitted by hot metals and "Corpuscles are also given out by metals and other bodies, but especially by the alkali metals, when these are exposed to light. They are being continually given out in large quantities and with very great velocities by radioactive substances such as uranium and radium; they are produced in large quantities when salts are put into flames, and there is good reason to suppose that corpuscles reach us from the sun."   Thomson also describes water drop experiments that enabled him to obtain a value for e that is about twice the modern value, and close to the then current value for the charge on a hydrogen ion in an electrolyte.

Is there any objection? Perhaps these could be moved to the [[J.J. Thomson]] page or somewhere else? Thanks.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 17:10, 25 August 2008 (UTC)

I'm for anything that better explains the electron as being a real physical particle and leaves the question as to how it was created and how it functions.WFPM[[User:WFPM|WFPM]] ([[User talk:WFPM|talk]]) 22:05, 25 August 2008 (UTC)

I do not object to you getting rid of JJ Thomson, with your 1984-newspeak mentality and writing him out of textbooks, like Tesla, and those before him. That is if you do not object to me calling the electron what it is:
*A dogma
*anti-intelectual propaganda ,to promote
*a blatent non-scientific construct to an artificial reality
*hidden and frusterating to the would be scientist.
The scienfic method states, that you need OBSERVATION. Well I havent observed any electrons, I do not believe them to be scientific. Why dont you go erase all the history of science (including the scientific method), and replace it with your own occult priesthood?  <small>—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/202.89.32.166|202.89.32.166]] ([[User talk:202.89.32.166|talk]]) 02:18, 26 August 2008 (UTC)</small><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->

== Negatron Needed! ==

Hello. I just thought I would tell you I am going to suggest the term "negatron" to Fermilab asking them to change the antiproton's name to negatron.  <small>—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/75.104.128.36|75.104.128.36]] ([[User talk:75.104.128.36|talk]]) 21:41, 25 August 2008 (UTC)</small><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->
:Please see ''Keep on topic'' under [[Wikipedia:Talk_page_guidelines#How_to_use_article_talk_pages]].&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:53, 25 August 2008 (UTC)

== Making it clear for a lay reader ==

Look, I do have a physics degree, and I can understand the vast majority of what is stated here, but it it going to be clear for a layreader?

The opening paragraph is too technical:

"The electron is a fundamental subatomic particle that carries a negative electric charge. It is a spin-½ lepton that participates in electromagnetic interactions, its mass is approximately 1 / 1836 of the proton. Together with atomic nuclei (protons and neutrons), electrons make up atoms. Their interaction with adjacent nuclei is the main cause of chemical bonding."

I think we should aim to make article understandable for the average person, particularly in the opening section.

I think it would be better if the opening section read as folloms:

"The electron is a fundamental subatomic particle that carries a negative electric charge. It participates in electromagnetic interactions and its mass is approximately 1 / 1836 of the proton. Together with atomic nuclei (protons and neutrons), electrons make up atoms. Their interaction with adjacent nuclei is the main cause of chemical bonding."

and then later went on to explain the term "is a spin-½ lepton". This article presupposes far too much on the part of the reader.
-confusedmiked  <small>—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/138.40.24.189|138.40.24.189]] ([[User talk:138.40.24.189|talk]]) 14:28, 4 January 2008 (UTC)</small><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->

{{Technical|date=September 2010}}
: See above. [[Special:Contributions/69.140.152.55|69.140.152.55]] ([[User talk:69.140.152.55|talk]]) 18:18, 18 September 2008 (UTC)

::I've been working steadily to enhance the article (since [https://secure.wikimedia.org/wikipedia/en/w/index.php?title=Electron&oldid=233784558 here]), including making it more readable for the lay reader. But it's a long, long way from being finished. Yes the lead needs work, but personally I prefer to leave addressing the lead section until the last; that way all the ducks are in a row and the lead can be written to reflect the article content. Yes I want to make the article easier to read and bring it up to FA quality, but that is just going to take time. (It is a lot of work tracking down suitable references and trying to make it both clear and correct.) Once it is ready, I plan to take it through the standard PR/GA/FA review process, and then it will get a good copy-edit. Until that happens, well if your template addition manages to attract any useful help, I'll be pleasantly surprised. ;-) Thanks for the feedback.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 20:16, 18 September 2008 (UTC)

== Proposed replacement for infobox image ==

[[Image:Nasa_Shuttle_Test_Using_Electron_Beam_full.jpg|right|thumb|240px|During a [[NASA]] [[wind tunnel]] test, a model of the [[Space Shuttle]] is targeted by a beam of electrons; simulating the effect of [[ion]]izing gasses during [[re-entry]].[http://grin.hq.nasa.gov/ABSTRACTS/GPN-2000-003012.html] ]]

It seems to me the current lead image requires too much explanation and reader knowledge to properly understand. Thus I started looking through the commons and came upon the dramatic image to the right. What do you think about it as a replacement? It could be visually appealing for the casual visitor. Would anybody object to me moving it into place? Thanks.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 22:42, 18 September 2008 (UTC)

That is a nice picture. I think this would be a good for the casual reader. Now to explain how this image is related to a theory, that was proposed by stoney, then thomson did the experiment and refused to accept stoneys theory. So how does the story continue? How does this picture relate to why Thomson was wrong?  <span style="font-size: smaller;" class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/60.234.30.229|60.234.30.229]] ([[User talk:60.234.30.229|talk]]) 01:05, 19 September 2008 (UTC)</span><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->
:Thank you for your feedback.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 03:17, 20 September 2008 (UTC)
::There was no objection, so I implemented the cnage.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 15:27, 23 September 2008 (UTC)

== To-do list ==

Here is my to-do notes for this page:

* <s>Explain low mass of the electron by the lack of interaction via the strong force.</s> :: ''no GUT yet, so can't really cover this.''
* [[Beta radiation]]. Hazards and health effects. Effects on spacecraft and satellites.
* <s>[[Bohr radius]].</s> :: ''covered by atomic orbital article and sub-pages.''
* <s>The [[fine-structure constant]] (for electron interaction).</s>
* <s>Electron [[plasma]] and [[Bremsstrahlung]] radiation</s>.
* <s>[[Compton scattering]] and [[inverse compton scattering]].</s>
* <s>[[Hawking radiation]]: electron-positron pair production around a [[black hole]].</s>
* Improve and expand existing material. Clarify text for non-physicists. <s>Perhaps tone down the formulae in the "Motion and energy" section to just what is needed.</s>
* <s>Single paragraph summaries of magnetism, electrical conductivity, heat conductivity and solid-state matter. [[Wiedemann-Franz law]].</s>
* <s>Expand "Visualization" to be a section on electron detection and observation, including the Penning trap</s>.
* Expand and cite applications section, including [[quantum computer]].
* Update the lead to comply with MoS and cover the article.

&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 15:35, 21 September 2008 (UTC)

==Electron information/Stern-Gerlach==
>Chemistry is part of the definition of electron. <br>
Which electron information would you put in that relates to <strike>electrons</strike> chemistry?  With references please.

:Well as I see it you can discuss electrons as individual particle-waves and then you can discuss multiple electrons, or electrons en masse. The first seems like a must-have for this article; the second is part of the subject matter of a number of other wikipedia articles. I think that the [[Wikipedia:Summary style]] policy can be applied to the second.
:As for supplying references, well you're certainly welcome to track them down yourself. I recommend the scholar search on Google as a good starting point. Thanks. =)&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:19, 4 October 2008 (UTC)

Changing subjects: Is someone aware of a highly accurate measurement of the stern-gerlach experiment, using particle detector?  I remember reading that in a book but couldn't find it again.  The book concluded that electron placement at the end was sinusoidal and not a split like most text books lead you to believe. [[User:Daniel.Cardenas|Daniel.Cardenas]] ([[User talk:Daniel.Cardenas|talk]]) 20:02, 4 October 2008 (UTC)
:You might try asking this on the [[Talk:Stern–Gerlach experiment]] page.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:29, 4 October 2008 (UTC)

== Number of electrons ==

In the [[atom]] article, we could not find a sufficiently authoritative source (such as a scientific journal article) for the number of atoms in the universe, so we ended up just listing the average density of atoms. The following text has the same issue, so I am relocating it here (in lieu of an excellent reference):

:Scientists believe that the number of electrons existing in the known [[universe]] is at least 10<sup>79</sup>. This number amounts to an average density of about one electron per [[cubic metre]] of space.  Astronomers have estimated that 90% of the mass of atoms in the universe is [[hydrogen]], which is made of one electron and one proton.{{Citation needed|date=September 2008}}

The atom article already covers this topic, so personally I think it's only necessary to state that the universe has no net charge.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 18:23, 28 September 2008 (UTC)

:The trouble is that nobody knows how big the universe is. Density, on the other hand, can be measured pretty accurately. You can always get an estimate for the amount of something in the [[observable universe]] by multiplying the density by (4/3) π (46 billion light years)³. -- [[User:BenRG|BenRG]] ([[User talk:BenRG|talk]]) 21:28, 2 October 2008 (UTC)

::Yep. Perhaps it might be interesting to provide some information about the relative density of free electrons (compared to non-ionized atoms) in various regions of space? E.g. solar wind, interstellar space, galactic jets, &c.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:46, 2 October 2008 (UTC)

== Unsourced ==

I'm moving the following text here because I don't know the source, includes a lot of jargon and (at the beginning) unnecessary vagueness, and I don't think it's helpful, summary-wise. I think it belongs on one of the electron microscope pages.

:The uniquely high charge-to-mass ratio of electrons means that they interact strongly with atoms, and are easy to accelerate and focus with electric and magnetic fields. Hence there are [[Transmission Electron Aberration-corrected Microscope|aberration-corrected]] transmission [[electron microscope]]s that use 300&nbsp;keV electrons with velocities greater than the speed light travels in water (approximately 1/2 to 2/3 of ''c''), wavelengths below 2 picometers, transverse coherence-widths over a nanometer, and longitudinal coherence-widths 100 times that. This allows such microscopes to image scattering from individual atomic-nuclei ([[Annular dark-field imaging|HAADF]]) as well as interference-contrast from solid-specimen exit-surface deBroglie-phase ([[HRTEM]]) with lateral [[Image resolution|point-resolutions]] down to 60 picometers.  Magnifications approaching 100 million are needed to make the image detail comfortably visible to the naked eye.

Here's some more for which I couldn't find a good citation.

:At energies of just a few<!-- how many? --> electron volts this wavelength determines the size of atoms, while at thousands of electron volts this results in the [[Bragg angle]]s for [[electron diffraction]].{{Citation needed|date=October 2008}} ([[J. J. Thomson]]'s son [[George Paget Thomson|G. P. Thomson]] discovered this angle to be much smaller than one degree.)

&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 18:33, 21 October 2008 (UTC)

== "standardized" value of spin? ==

<blockquote>It has a property of intrinsic angular momentum called spin, with a standardized value of 1⁄2.</blockquote>
The use of the word "standardized" sounds quite strange here, as the fact that the electron is a spin-1/2 particle was decided by God Almighty (or nature, or whatever you call him/her/it), not by the International Organization for Standardization. (I understand [[natural units|what it's supposed to mean]], but few people reading ''the lead'' of this article will.)
Also, it is not very clear what "value" means in this context: spin is a vector (not quite, but more similar to a vector than to a scalar), whose magnitude is ''ħ''{{radic|''s''(''s'' + 1)}}, and the eigenvalues of the operator corresponding to its projection along any axis are −''ħs'', …, +''ħs'' in steps of ''ħ''. it is ''s'', the spin quantum number, which is 1/2 for electrons. But, right now, I can't find any way of saying that which is ''both'' at a level adeguated to a lead section, ''and'' not factually incorrect. Until I find it, I'm just removing "standardized" – that word is really useless, there. --<span style="font-family: monospace; font-weight: 600; color: #00F; background-color: #FFF"> [[User:Army1987|Army]][[1987]][[User talk:Army1987|&nbsp;(t&nbsp;]][[Special:Contributions/Army1987|—&nbsp;c)]]</span> 17:27, 24 October 2008 (UTC)

:Say something like of "...a spin of {{frac|1|2}}&nbsp;ħ (often written as spin {{frac|1|2}}, where ħ is either implicit, or [[natural units|normalized to 1]])".[[User:Headbomb|Headbomb]] {[[User talk:Headbomb|ταλκ]] – [[WP:PHYS|WP Physics]]: [[Wikipedia:WikiProject Physics/Projects of the Week|PotW]]} 17:37, 24 October 2008 (UTC)

::But, usually, when one talks about the value of a (pseudo)vector (e.g. "a force of 100 newtons") one is likely to refer to its magnitude, not to one of its components. So, a reader unfamiliar with spin could get the wrong impression. [http://en.wikipedia.org/w/index.php?title=Electron&diff=247429438&oldid=247417944 This] is what I did, but I fear it might be somewhat too verbose for a lead section. --<span style="font-family: monospace; font-weight: 600; color: #00F; background-color: #FFF"> [[User:Army1987|Army]][[1987]][[User talk:Army1987|&nbsp;(t&nbsp;]][[Special:Contributions/Army1987|—&nbsp;c)]]</span> 18:36, 24 October 2008 (UTC)

:::For a lead section, it might be enough to refer to the electron as a spin ½ particle. The reader unfamiliar with the concept will get more information from the [[spin]] page than what could/should be put into a lead. For example, that is exactly how elementary charge is treated in the same paragraph. After all, this article is about the electron and not about spin. --[[User:Blennow|Blennow]] ([[User talk:Blennow|talk]]) 19:00, 24 October 2008 (UTC)

::::But just saying "The electron is a [[spin-½]] particle." in the lead without giving a clue of what it means doesn't sound right to me, either, in view of [[WP:MTAA]]. There ''must'' be some compromise between these two extremes; something like "The electron is a [[spin-½]] particle, meaning that its [[spin (physics)|spin]] (intrinsic [[angular momentum]])…", where the "…" denotes text which is no longer than approximately 80 characters, doesn't use terms which less than 1% of readers can understand such as "eigenvalue", and does not contain factual inaccuracies. Now, the difficult part is finding a reasonable expansion for that "…". --<span style="font-family: monospace; font-weight: 600; color: #00F; background-color: #FFF"> [[User:Army1987|Army]][[1987]][[User talk:Army1987|&nbsp;(t&nbsp;]][[Special:Contributions/Army1987|—&nbsp;c)]]</span> 21:12, 24 October 2008 (UTC)

:::::I see your point and I agree to some extent. However, let me again make the parallel with the elementary charge case. Sure, people may be more familiar with the concept of charge than with spin, but the lead does not try to explain it any further - one could, but definitely should not, start speaking about electromagnetic charge as the eigenvalue of the hypercharge plus the third component of the isospin. Since the article on [[spin]] is there - why not simply link to it? Of course, one may also mention that it is related to the intrinsic angular momentum, which people may be more familiar with. Maybe something like "The [[spin]], a quantity related to the intrinsic [[angular momentum]] of a particle, of the electron is ½." --[[User:Blennow|Blennow]] ([[User talk:Blennow|talk]]) 21:49, 24 October 2008 (UTC)

== Values of electron mass ==

According to the infobox, the electron has a mass of {{val|5.48579909|(27)|e=-4|u=u}} and the reference is the 2006 CODATA recommended value. In the latest version of the ''Review of Particle Physics'', the value is quoted as {{val|5.4857990943|(23)|e=-4|u=u}} - also quoting the 2006 CODATA recommended value. Also the quoted values for the mass in eV ({{val|0.510998910|(13)|u=MeV/c2}}) differ although the value in units of kg is the same. (The difference in the relative errors is attributed to the electron mass actually being measured in atomic mass units, while the relative error in the conversion factors are larger than the error in this measured value.) I don't have access to the CODATA recommendations since I am not at work, anyone who has might want to check it out to resolve this ... --[[User:Blennow|Blennow]] ([[User talk:Blennow|talk]]) 19:21, 24 October 2008 (UTC)
:The CODATA recommendations are freely accessible from the NIST website, I've updated the values referencing it. The values now present in the article have smaller uncertainties than those which I replaced, so I suppose they are more recent. --<span style="font-family: monospace; font-weight: 600; color: #00F; background-color: #FFF"> [[User:Army1987|Army]][[1987]][[User talk:Army1987|&nbsp;(t&nbsp;]][[Special:Contributions/Army1987|—&nbsp;c)]]</span> 21:54, 24 October 2008 (UTC)

::Yes, they seem to be the same as those quoted in the latest edition of ''Review of Particle Physics''. However, I just noticed there seems to be a problem with the <nowiki>{{</nowiki>[[Template:Val|val]]<nowiki>}}</nowiki> template. It cuts the value after the ninth decimal, i.e., <nowiki>{{val|5.4857990943|(23)|e=-4|u=u}}</nowiki> is displaying as {{val|5.4857990943|(23)|e=-4|u=u}}. Unless one wants to drop the template, I guess the temporary solution would be {{val|5.485799094|(3)|e=-4|u=u}} - at least until someone measures the electron mass with a higher accuracy … --[[User:Blennow|Blennow]] ([[User talk:Blennow|talk]]) 22:20, 24 October 2008 (UTC)

:::That bloody template... Fixed. --<span style="font-family: monospace; font-weight: 600; color: #00F; background-color: #FFF"> [[User:Army1987|Army]][[1987]][[User talk:Army1987|&nbsp;(t&nbsp;]][[Special:Contributions/Army1987|—&nbsp;c)]]</span> 23:16, 24 October 2008 (UTC)

== PR item checklist ==

Checklist of PR items I need to follow up:

* <s>Modern particle physics: ...I would add ... a paragraph about development of quantum electrodynamics at the end of 1940s (works of [[Julian Schwinger]] on [[anomalous magnetic moment]] of electron).</s>
* <s>Fundamental properties: "This is the radius that is inferred from the electron's electric charge, by using the classical theory of electrodynamics alone and ignoring quantum mechanics." I would put a footnote here with a formula.</s>

Virtual particles:
* <s>The third paragraph should make it clear that the mass of the electron is not in reality reduced as result of radiative corrections&mdash;it is simply taken from the experiment, and all terms that influence the mass are replaced with this real mass during renormalization.</s>
** I attempted to address this, but I'm not completely sure I understood his concern correctly.
* <s>Please, add a note to explain how <math>\sqrt{3}/2</math> is obtained.</s>
* <s>In the last paragraph. I think it is not necessary to introduce g-factor. Say simply that the magnetic moment of electron is almost equal to one Borh magneton. 0.1% difference is explained by radiative corrections (see Schwinger above).</s>

Interaction subsection:
* <s>"Electrons are a key element in electromagnetism, a theory that is accurate for macroscopic systems, and for classical modeling of microscopic systems'" quite a meaningless sentence, in my opinion. Electromagnetism is not a theory, it is a set of phenomena. It should be omitted or rewritten. For instance "Electrons are a key element in the [[Free electron model|electron theory of metals]], [[atomic physics|atomic]] and [[molecular physics]] and in [[chemistry]]."</s>
* <s>"quanta of electromagnetic energy" -> "quanta of electromagnetic field". Photon is a quanta of everything: [[momentum]], angular momentum, energy.</s>
* Fine structure constant is also called a dimensionless charge squared <math>\alpha=e^2/(\hbar c)</math> (in CGS system). If <math>\hbar=c=1</math> assumed, <math>\alpha=e^2</math>.
** I think this may be a little off topic for this article. So I'm planning to leave it for the [[fine structure constant]] article.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 20:12, 13 November 2008 (UTC)
* <s>"The full electromagnetic effect from a moving charge can be derived mathematically using the Liénard-Wiechert potential, which includes special corrections for when the velocity is close to the speed of light; known as relativistic velocities." an awkward sentence. I suggest: "The electromagnetic field of an arbitrary moving charged particle is expressed by the [[Liénard-Wiechert Potentials]], which are valid even when the particle's speed is close to that of light."</s>
* <s>"In the theory of electroweak interaction, the electron forms a weak isospin doublet with the electron neutrino." Actually only left-handed fermions forms isospin doublets; right-handed are isospin singlets.</s>

Motion and energy:
* "For the 51 GeV electron above, proper-velocity is approximately γc,[note 7] making the wavelength of those electrons small enough to explore structures well below the size of an atomic nucleus." This is not proper velocity, this is [[phase velocity]] of the de Broglie waves.
** Removed because I could not find a reference.

Other:
* <s>Other subsection should generally discuss [[synchrotron radiation]] sources, not only FELs.</s>
** There is some discussion of other sources in the Observation section, and I added a few notes the the Laboratory section.

&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 15:57, 2 November 2008 (UTC)

Other possibilities:

* [[Spintronics]] and [[quantum computing]].
* How do virtual photons transmit charge sign to electron when they are uncharged?
*: Virtual photons do not transmit any charge. Electrical charge conservation law is strictly satisfied for every vertex. [[User:Ruslik0|Ruslik]] ([[User talk:Ruslik0|talk]]) 12:23, 22 November 2008 (UTC)

&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 19:50, 11 November 2008 (UTC)

== Unsourced ==

In terms of referencing, this sentence has proven to be the biggest headache in the article. I'm moving it here because I could not find a suitable citation and there may be an error: it is apparently the [[phase velocity]] rather than the [[proper velocity]].

:For the 51&nbsp;GeV electron above, [[proper velocity|proper-velocity]] is approximately ''γc'',<nowiki><ref group=note></nowiki>Since momentum is mass times proper-velocity, ''w''&nbsp;=&nbsp;''γv'',

:<math>\begin{smallmatrix}\lambda_e\ =\ \frac{h}{p}\ =\ \frac{h}{m_e \gamma v}\ =\ \frac {h c}{\sqrt{K_e^2\ +\ 2 K_e m_e c^2}}.\end{smallmatrix}</math><nowiki></ref></nowiki>...

If you have the original source for this statement, please let me know. Otherwise, I think the paragraph is fine without it. Thanks.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 17:09, 14 November 2008 (UTC)
== Charge of the electron and possible reference==
I have found multiple references to the charge of the electron being 1.2 *10^19 C in early articles in the Americian Institute of Electrical Engineers. Can anyone clarify, why the charge of the electron was changed?{{Citation needed|date=September 2010}}
:: Please, provide at least one. [[User:Ruslik0|Ruslik]] ([[User talk:Ruslik0|talk]]) 09:31, 25 November 2008 (UTC)

:The charge didn't change, the measurements and measuring techniques improved.[[User:Headbomb|Headbomb]] {<sup>[[User talk:Headbomb|ταλκ]]</sup><sub style="margin-left:-3.5ex;">[[Special:Contributions/Headbomb|κοντριβς]]</sub> – [[WP:PHYS|WP Physics]]} 08:48, 22 November 2008 (UTC)

From Americian Instutite of electrical engingeers vol 26.1, 1907 on page 651 by Samual Sheldon, article title "The properties of electrons": quote: "each electron carries an invariable negative charge of 1.1 *10^-19 Columb."
*Question: how was the charge of the electron actually measured?
*Question2: What changed in how the charge was measured? [[User:Phillycheesesteaks|Phillycheesesteaks]] ([[User talk:Phillycheesesteaks|talk]]) 14:51, 7 January 2009 (UTC)

Note to other readers: Phillycheesesteaks is a sock puppet of a known troll.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:43, 7 January 2009 (UTC)
:What is the name of the master? [[User:Ruslik0|Ruslik]] ([[User talk:Ruslik0|talk]]) 21:56, 7 January 2009 (UTC)
::He has used many aliases, such as [[User_talk:AtomicKiwi]].&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 22:11, 7 January 2009 (UTC)
:Sock blocked. [[User:Vsmith|Vsmith]] ([[User talk:Vsmith|talk]]) 04:33, 8 January 2009 (UTC)

== Positronium issues ==

The following sentence was just added:

:In this case, [[Positronium|positronium atom]]s are the short lived species that can form between low speed electrons and positrons.

The issues are that it does not avoid [[Wikipedia:Manual_of_Style#Unnecessary_vagueness|unnecessary vagueness]] (how low a speed?; how short a lifetime?) and it is [[Wikipedia:Citing sources|unsourced]]. As this page is in the middle of a [[WP:FAC]], I'm temporarily moving it here until these issues are addressed. Sorry.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 16:43, 16 January 2009 (UTC)
:I think it's going a bit far from the subject of the article anyway. I have a source if people really want a short sentence about such phenomena. [[User:Physchim62|Physchim62]] [[User talk:Physchim62|(talk)]] 17:22, 16 January 2009 (UTC)
:: I admit to being tempted toward just making [[Positronium]] a link in the "See also" section.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 20:11, 16 January 2009 (UTC)
:::Reinserted with source more efficiently =). Sorry to contribute to any minor inconvenience during a FAC. But IMHO, I have to strongly disagree that it is a "bit far from the subject"! -[[User:Shootbamboo|Shootbamboo]] ([[User talk:Shootbamboo|talk]]) 00:17, 17 January 2009 (UTC)
:Different criteria, that's all! I would include muonium before positronium, as it results from the ''substitution'' of an electron and hence gives an idea of the electron's position in the [[Standard Model|scheme of things]]. I don't think that either are '''''essential''''' to a discussion of the electron, although both are obviously interesting in their own right! [[User:Physchim62|Physchim62]] [[User talk:Physchim62|(talk)]] 01:15, 17 January 2009 (UTC)

== Lead modification ==

As a result of objections raised during the FAC, I am proposing to once again modify the 4th and 5th sentences in the second paragraph that deal with the spin. Here is a first draft:

:The intrinsic [[angular momentum]] of an electron is called its [[spin (physics)|spin]]. Each electron occupies a [[quantum state]] that describes its random behavior upon measuring a physical parameter, such as its energy or spin orientation. No two electrons can occupy the same quantum state; a property known as the [[Pauli exclusion principle]].

Any thoughts?&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 19:15, 18 January 2009 (UTC)

P.S. I've requested that the FAC be withdrawn as I don't have enough time right now to address all the issues.&mdash;[[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 20:56, 18 January 2009 (UTC)