Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Anode
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Etymology== The word was coined in 1834 from the [[Greek language|Greek]] αΌΞ½ΞΏΞ΄ΞΏΟ (''anodos''), 'ascent', by [[William Whewell]], who had been consulted<ref name="Ross 1961" /> by [[Michael Faraday]] over some new names needed to complete a paper on the recently discovered process of [[electrolysis]]. In that paper Faraday explained that when an electrolytic cell is oriented so that electric current traverses the "decomposing body" (electrolyte) in a direction "from East to West, or, which will strengthen this help to the memory, that in which the sun appears to move", the anode is where the current enters the electrolyte, on the East side: "''ano'' upwards, ''odos'' a way; the way which the sun rises".<ref>{{cite journal|author=Faraday, Michael|title=Experimental Researches in Electricity. Seventh Series|url=http://www.gutenberg.org/ebooks/14986|journal=Philosophical Transactions of the Royal Society|volume=124|issue=1|date=January 1834|page=77|doi=10.1098/rstl.1834.0008|url-status=live|archive-url=https://web.archive.org/web/20171209152633/http://www.gutenberg.org/ebooks/14986|archive-date=9 December 2017|bibcode=1834RSPT..124...77F|s2cid=116224057|url-access=subscription}} in which Faraday introduces the words ''[[electrode]]'', ''anode'', ''[[cathode]]'', ''[[anion]]'', ''[[cation]]'', ''[[electrolyte]]'', ''[[electrolyze]]''</ref><ref>{{cite book|author=Faraday, Michael|title=Experimental Researches in Electricity|volume=1|year=1849|publisher=Taylor|url=http://www.gutenberg.org/ebooks/14986|hdl=2027/uc1.b4484853|url-status=live|archive-url=https://web.archive.org/web/20171209152633/http://www.gutenberg.org/ebooks/14986|archive-date=9 December 2017}} Reprint</ref> The use of 'East' to mean the 'in' direction (actually 'in' β 'East' β 'sunrise' β 'up') may appear contrived. Previously, as related in the first reference cited above, Faraday had used the more straightforward term "eisode" (the doorway where the current enters). His motivation for changing it to something meaning 'the East electrode' (other candidates had been "eastode", "oriode" and "anatolode") was to make it immune to a possible later change in the direction convention for [[electric current|current]], whose exact nature was not known at the time. The reference he used to this effect was the Earth's magnetic field direction, which at that time was believed to be invariant. He fundamentally defined his arbitrary orientation for the cell as being that in which the internal current would run parallel to and in the same direction as a hypothetical [[solenoid|magnetizing current loop]] around the local line of latitude which would induce a magnetic [[dipole]] field oriented like the Earth's. This made the internal current East to West as previously mentioned, but in the event of a later convention change it would have become West to East, so that the East electrode would not have been the 'way in' any more. Therefore, "eisode" would have become inappropriate, whereas "anode" meaning 'East electrode' would have remained correct with respect to the unchanged direction of the actual phenomenon underlying the current, then unknown but, he thought, unambiguously defined by the magnetic reference. In retrospect the name change was unfortunate, not only because the Greek roots alone do not reveal the anode's function any more, but more importantly because as we now know, the Earth's magnetic field direction on which the "anode" term is based is subject to [[Geomagnetic reversal|reversals]] whereas the [[electric current|current]] direction convention on which the "eisode" term was based has no reason to change in the future.{{Citation needed|date=February 2024}} Since the later discovery of the [[electron]], an easier to remember and more durably correct technically although historically false, etymology has been suggested: anode, from the Greek ''anodos'', 'way up', 'the way (up) out of the cell (or other device) for electrons'.{{Citation needed|date=February 2024}}
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)