Talk:Electrode

message: The image top right of the Cathode page shows a b+ sign, so I'm guessing it is connected to positive of a battery?  If so, the current should be flowing from there to negative, yet the electrons (which have negative charge) are shown flowing in the same direction.  I might be completely wrong here, but I think this might need addressing.  /Mat 82.69.54.182 00:00, 1 October 2006 (UTC)
replies: text: Hi Matt, there is a lot of confusion about polarity i.e. positive/negative charges and where the electrons are going. It is the most edited part of the article. The main reason for the confusion is that the polarity is referential - to one side of an electrode the charge is negative and to the other side of the same electrode the charge of the same electrode is positive. If you consider it strictly by electron flow it all sorts out.Jonathan888 (talk) 15:04, 10 October 2006 (UTC)
thread_title:  The image 

message: It hasn't helped me in the slightest with my biology thing
I am even more confused than i was before i think it's irresponsable to make pages like this that only cause confusion, missery and upset to all who read them.  What is anyone ment to do with this information.  Reduce it to One sentance: A Cathode is (Negative) / (Posative)   (ommit the right one somebody!!! :'(
:-(
:Once again, there is not a simple answer to 'positive' / 'negative' because the voltage polarity is dependant upon where you are measuring from - external to the device a cathode appears positive as electrons are flowing into the device through the cathode and the charge to draw the electrons in must be positive.  Inside the device the cathode appears negative since it is the source of the electrons to the device.  Therefore, if you measure from the circuit to the device's cathode you get a a 'positive' polarity reading, if you measure from the cathode to the anode you get a 'negative' polarity reading.  This page is not meant to be an easy crib sheet for your biology 'thing' but rather a technically accurate description of electrodes and their functions.Jonathan888 (talk) 22:00, 31 October 2006 (UTC)
thread_title:  This page is dreadful 

message: I'm replying to a request that Jonathan888 made on my Talk page. There is no final answer, because there is no universal authority on what anode and cathode mean. Chemists define them in terms of redox; electronics engineers in terms of electrons; and physicists in terms of conventional current. Apparently, there are even some battery makers who ignore the science and assign them to fixed polarities. All of these definitions (except the battery makers') are equivalent, so what do we do?
I can see arguments for and against all three versions:
* Redox
** For: Avoids taking sides in the electrons/conventional current war. The clearest definition for electrochemists. A nice opportunity to mention Faraday.
** Against: Not helpful for non-chemists who only want to know what to call the pointy end of a diode.
* Electrons
** For: Describes what is going on in metallic circuits, which are the most common type of conductor in everyday engineering.
** Against: Ignores other conduction mechanisms, although the actual use of non-electronic conduction to a cell's electrodes is rare to non-existent
* Current
** For: The most general definition. Cannot be contradicted even by hair-splitting physicists. ;-) Will annoy those pesky electron current advocates. :-D
** Against: As Jonathan888 points out, it divorces the definition from physical reality, and might lead students to think that conventional current actually flows in and out of electrodes. However, this criticism could be made of the use of conventional current in general, which is nevertheless pretty popular.
I'm reluctant to take sides. I think I can rule out the chemical definition, because it's too specific. Emotionally, I prefer the electron version, because I feel that I know where I am with electrons, and that's the version that I originally promoted. Rationally, I prefer the conventional current version, because it's the only one that doesn't exclude any possibilities that I can think of, even though it's based on an arbitrary convention. So I'm going to have to come down, weakly, on the side of conventional current. I am concerned, however, that the upheaval that this will cause to the article might make a mess of it in the short term, so let's be careful if we go down that route, please. How about a practice definition here on the talk page? --Heron 11:22, 13 December 2006 (UTC)
thread_title:  Definition 

message: In retrospect, one thing tickled me in Wikipedia's attractive "way up for electrons" and "way down for electrons" explanation for Faraday's naming of the anode ('way up') and cathode ('way down') electrodes ('elektron ways'), which had made such perfect sense to me that I had reworded it without even questioning it in the new "Etymology" section of the Anode article. That thing was: had the electron already been discovered in the 1830's ???
When I found that the electron was only discovered about 40 years later (in 1874), I realized that 'elektron' in the etymology of 'electrode' must have meant electricity rather than electron and that the Wikipedia explanation was wrong, but then what was it that went up on the anode side and down on the cathode side in Faraday's mind, since it couldn't be electrons? I found the answer in Faraday's original paper: the sun, as ludicrous as this may seem! Here is the link to Faraday's original 1834 paper (Gutenberg.org's html version) and a few relevant extracts, which BTW provide authoritative support to Wikipedia's new current-based definition:
 :
<<...In place of the term pole, I propose using that of Electrode (footnote:"[Greek: elektron], and [Greek: -odos] a way.")...The surfaces at which, according to common phraseology, the electric current enters and leaves a decomposing body, are most important places of action... Wishing for a natural standard of electric direction to which I might refer these, ..., I have thought it might be found in the earth. If the magnetism of the earth be due to electric currents passing round it, the latter must be in a constant direction, which, according to present usage of speech, would be from east to west, or, which will strengthen this help to the memory, that in which the sun appears to move. If in any case of electro-decomposition we consider the decomposing body as placed so that the current passing through it shall be in the same direction, and parallel to that supposed to exist in the earth, then the surfaces at which the electricity is passing into and out of the substance would have an invariable reference, and exhibit constantly the same relations of powers. Upon this notion we purpose calling that towards the east the anode (footnote:"[Greek: ano] upwards, and [Greek: -odos] a way; the way which the sun rises."), and that towards the west the cathode (footnote:"[Greek: kata] downwards, and [Greek: -odos] a way; the way which the sun sets."); ... The anode is therefore that surface at which the electric current, according to our present expression, enters... The cathode is that surface at which the current leaves the decomposing body...>>
Some rewriting of the various articles is in order I am afraid, who volunteers? ;-) MichelJullian 16:15, 22 December 2006 (UTC)
replies: text: Great work, Michel. I have changed the etymology in anode to reflect the Faraday-Whewell letters, which are fascinating reading. Luckily there wasn't much in cathode that needed rewriting. If there are any more articles that need attention, just let me know and I will be happy to help - unless you want to edit them yourself, of course. --Heron 19:22, 22 December 2006 (UTC)
thread_title:  Faraday's original naming based on ascent/descent of sun, not of electrons :)) 

message: I have a BS in Physics and a MS in electrical engineering but I've never known there was so much confusion over the meaning of cathode and anode until today.  Good work to those of you who have really looked into this.  
I would add that there is no such thing as a cathode or an anode unless you provide a conduction path between two metals with different electron affinities(or there might be other elements too that are capable of sustaining a current, I'm not sure.)  And before the current begins flowing, neither one of the metals (which constitute the electrodes) are net positive or negatively charged.  And also, due to the electrolytic solution, or whatever other method might be used in batteries to keep the electrodes both with net neutral charge by use of ion flow, NEITHER ELECTRODE IS ACTUALLY EVER NET POSITIVE OR NEGATIVE (to all most practical approximations.)  So I think that really it's a flaw in the convention to call either positive or negative.  
But, the way I like to think of it is that of course the electrons will flow through the circuit to the positive.  And that a cation is a positively charged ion (I don't believe there's any argument by anyone over that term), so the electron flow is TO the CATHODE.  And I think it would be worth looking at whether the term "cation" for a net positively charged ion was instituted before the term cathode.  I always assumed that cation had come first.  
Also, the anode article starts out just by describing current flow as electron flow.  This is a major problem to me, as I have always in both physics and EE read in all texts, and been instructed by every professor, that current flow is positive charge flow unless you specify otherwise.  I'm going to edit that now.
:Dear anonymous, please open an account, read carefully both the articles and the talk page, and discuss your planned changes here prior to making major edits. Current flow is indeed positive charge flow, but you should be aware that it is also negative charge flowing in reverse. You replaced "current flow into the device/cell" by "electron flow into the external circuit", which is the same thing except it's less general as discussed above. Plus it shifts the focus from the device comprising the electrode to the external circuit which is a bad idea. I will therefore revert your edits now. MichelJullian 12:15, 23 December 2006 (UTC)
replies: text: BTW cation was named after cathode, not the other way round, cf original paper in , Seventh Series. MichelJullian 10:09, 11 January 2007 (UTC)
thread_title:  Anonymous edits 

message: Memory helpers for the general defs of anode and cathode were cruelly missing IMHO, especially with the complex etymologies, so I added the following mnemonics, right after the defs for max effectiveness:
ACE Anode Current Enters
CCD Cathode Current Departs
Critics welcome but I submit making up silly mnemonics can hardly be considered as "original research", so please don't remove them MichelJullian 23:18, 28 February 2007 (UTC)
thread_title:  Mnemonics 

message: Hi all, first time using Wiki so apologies if I miss some kind of convention...
On the Cathode page, it appears to me that the description of device physics for diodes is backwards. It states that holes are supplied from the N type layer and electrons are supplied from the P type layer. Last time I checked N stood for excess Negative charge carriers (electrons) while P type has excess Positive charge carriers (holes). 
Jackjtang 18:53, 11 September 2007 (UTC)
thread_title:  Diode Device Physics 

message: Read an article referencing the "tracks" of an electrode.  I have no idea what they are...I was hoping this page would reference them but it doesn't.  If anyone knows, please add.  —Preceding unsigned comment added by 128.2.164.39 (talk) 03:29, 12 October 2007 (UTC)
thread_title:  Electrode Tracks? 

message: It seems to me that the common usage of the word electrode has been extended beyond the scope of this articles discussion, but in a way which still remains within the scope of the definition the article claims to discuss. 
For instance, the usage of electrode extends to other elements in vacuum tubes, and this generality possibly extends to other realms as well. More specifically, amplifier vacuum tubes contain a number of grid elements that are categorized as electrodes. I just came here from the photomultiplier article, which describes a dynode as a kind of electrode. There is also a photocathode article. I see that there are a great many articles that link to the electrode article, including the ones mentioned. I think this means that electrode is a key concept.
Perhaps this article could extend its discussion of electrode to encompass other uses of the term beyond anode and cathode or provide links to these other kinds of electrode. --AJim (talk) 14:09, 12 May 2009 (UTC)
thread_title:  intermediate electrodes 

message: how about some images?  —Preceding unsigned comment added by 84.215.44.177 (talk) 08:29, 29 January 2010 (UTC)
thread_title:  image?