Talk:Black body: Difference between revisions

Content deleted Content added

Inline

Latest revision as of 12:26, 17 August 2024

Black body was a good articles nominee, but did not meet the good article criteria at the time. There may be suggestions below for improving the article. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake.

Article milestones
Date	Process	Result
July 21, 2006	Good article nominee	Not listed

Physics Top‑importance

	Physics portal This article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics
Top	This article has been rated as Top-importance on the project's importance scale.

Color Mid‑importance

	This article is supported by WikiProject Color, a project that provides a central approach to color-related subjects on Wikipedia. Help us improve articles to good and 1.0 standards; visit the wikiproject page for more details.ColorWikipedia:WikiProject ColorTemplate:WikiProject Colorcolor
Mid	This article has been rated as Mid-importance on the project's importance scale.

Archives

Archive 1 (March 2004 – Nov 2009)
Archive 2 (July 2006 – Oct 2010)
Archive 3 (Dec 2010 – Jan 2012)
Archive 4 (Jan – Feb 2012)
Archive 5 (Jan – Feb 2012)
Archive 6 (Feb 2012 – )

This page has archives. Sections older than 90 days may be automatically archived by when more than 4 sections are present.

What is it for?

The article starts out with "A black body or blackbody is an idealized physical body...". At that point it should say why anyone would want to idealize a body and here should be examples of what a "body" is. I'm not expert enough to add it myself, but something along the lines of "... that is used as a stand-in for actual physical objects, such as planets and humans, in order to simplify the math required to model them."

Math error?

At the time of writing this comment, the Black Holes section has a formula that drops the following error (in the Brave browser, running on macOS Big Sur):

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "/mathoid/local/v1/":): {\displaystyle T=\frac {\hbar c^3}{8\pi Gk_\text{B}M} \ ,}

I'm not familiar enough with MathML or the <math> tag to be of any help, and my only hope is that someone who follows this page (or has it on their watchlist) is able to check it and correct the error.

Feel free to remove this message once the issue is fixed. — Gwyneth Llewelyn (talk) 19:17, 6 March 2023 (UTC)[reply]

Space to include band emission

The page for band emission could be easily slotted in to this article under Idealizations, though I don't know if there's enough there to warrant its own subheading or if it could be added under a heading like: Band emissions with justification of why measuring the emissions over a specific spectral band is useful. Reconrabbit (talk) 19:02, 11 December 2023 (UTC)[reply]

Black body absorption and emission? Which is king?

I am trying to understand black bodies (bb), not being a physicist. This article, like others I have read, talks about absorption and emissions of radiation. Absorption by a bb is defined to be 100% of incident radiation. In the next sentence, at the beginning, we are told that a bb emits radiation. Confusingly, that suggests that absorption is not 100%; some is going back out. Emission qualities depend on the temperature. Is the temperature determined by the absorbed radiation? Or just by an independent local heat source? Is the thermal capacity of the bb relevant to heating caused by absorbed radiation? Is the relevance of a bb to physics because it absorbs, it emits, or both? Or is it because it transforms incident radiation into outgoing radiation with different properties dependent on its temperature which is determined by what?? Any clarifications would be appreciated. KPD674 (talk) 11:35, 17 August 2024 (UTC)[reply]

@@ Line 1: / Line 1: @@
-{{Vital article|topic=Science|subpage=Physics|level=5|class=B}}
 {{ArticleHistory
 |action1=GAN
@@ Line 7: / Line 6: @@
 |currentstatus=FGAN
 }}
+{{WikiProject banner shell|class=B|vital=yes|1=
-{{WikiProjectBannerShell|1=
-{{WikiProject Physics|class=B|importance=Top}}
+{{WikiProject Physics|importance=Top}}
-{{WikiProject Color|class=B|importance=Mid}}
+{{WikiProject Color|importance=Mid}}
 }}
-{{Archive box |search=yes |bot=MiszaBot I |age=3 |units=months |index=/Archive index |
+{{Archive box |search=yes |bot=Lowercase sigmabot III |age=3 |units=months |index=/Archive index |
 * [[Talk:Black body/Archive 1|Archive 1]] <small>(March 2004 – Nov 2009)</small>
 * [[/Archive 2|Archive 2]] <small>(July 2006 – Oct 2010)</small>
@@ Line 32: / Line 31: @@
 }}
+== What is it for? ==
-== Experimental Apparatus - Cavity with a Hole ==
+The article starts out with ''"A black body or blackbody is an idealized physical body..."''. At that point it should say why anyone would want to idealize a body and here should be examples of what a "body" is. I'm not expert enough to add it myself, but something along the lines of ''"... that is used as a stand-in for actual physical objects, such as planets and humans, in order to simplify the math required to model them."''
-Since the experimental apparatus of Lummer and Kurlbaum is central to real world attempts to create a blackbody, I feel this section should be expanded.  Inclusion of a brief description of how the apparatus works and a figure would go a long ways to aiding reader comprehension.  I am not knowledgeable enough about experimental physics to do this myself, so could someone with the background please expand this section?
---[[User:BBUCommander|BBUCommander]] ([[User talk:BBUCommander|talk]]) 15:25, 19 August 2012 (UTC)
+== Math error? ==
-==Definition of a white body==
-Why is a white body necessarily rough?  Seems like this statement is not true and includes unnecessary detail.  The roughness or smoothness of an ideal black body is not mentioned. [[User:Neffk|neffk]] ([[User talk:Neffk|talk]])  <span style="font-size:smaller;" class="autosigned"> — Preceding [[Wikipedia:Signatures|undated]] comment added 15:24, 28 May 2015 (UTC)</span><!--Template:Undated--> <!--Autosigned by SineBot-->
+At the time of writing this comment, the [https://en.wikipedia.org/wiki/Black_body#Black_holes Black Holes section] has a formula that drops the following error (in the Brave browser, running on macOS Big Sur):
-:A white body is necessarily rough in the sense that its surface is lambertian. It reflects every finite sized incoming pencil into every direction. A black body completely absorbs rays from every direction. If the "black" surface were not rough, but had a shine on it, it would not really be black. If a body that reflects is not rough, it is a specular reflector, and is even more shiny than polished silver, not white.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 11:30, 29 May 2015 (UTC)
+<pre>
-== undid faulty IP edit; reasons ==
+Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "/mathoid/local/v1/":): {\displaystyle T=\frac {\hbar c^3}{8\pi Gk_\text{B}M} \ ,}
+</pre>
+I'm not familiar enough with MathML or the <code><nowiki><math></nowiki></code> tag to be of any help, and my only hope is that someone who follows this page (or has it on their watchlist) is able to check it and correct the error.
-I have undone a faulty IP edit.
+Feel free to remove this message once the issue is fixed. — [[User:GwynethLlewelyn|Gwyneth Llewelyn]] ([[User talk:GwynethLlewelyn|talk]]) 19:17, 6 March 2023 (UTC)
-There are two signs that a writer is cleverer than the reader: starting a sentence with 'actually'; and starting a sentence with 'however'. (Ordinary writers, however, use the word 'however' like this.)
+== Space to include [[band emission]] ==
-The new material may perhaps, suitably re-written, be a useful addition to the article, but not as it was posted just now, directly in the lead. One guesses, perhaps mistakenly, that perhaps it was posted not by an ordinary Wikipedia editor, but by the enthusiastic author of the cited paper seeking self-promotion, with a risk of [[WP:COI|conflict of interest]].
+The page for [[band emission]] could be easily slotted in to this article under Idealizations, though I don't know if there's enough there to warrant its own subheading or if it could be added under a heading like: <b>Band emissions</b> with justification of why measuring the emissions over a specific spectral band is useful. [[User:Reconrabbit|Reconrabbit]] ([[User talk:Reconrabbit|talk]]) 19:02, 11 December 2023 (UTC)
-The material may perhaps, with some careful editing, be suitable to be posted in a section of the body of the article, and then may be considered for possible inclusion in a brief summary form in the lead.
+== Black body absorption and emission? Which is king? ==
-No matter how much cleverer the poster than than the reader, the ordinary form of Kirchhoff's law does not need amendment. The law states the existence of a unique universal spectrum for thermodynamic equilibrium. That the posted material may contradict that would suggest that the posted material is not from a reliable source. Wikipedia does not admit in general that new research, in no matter how thoroughly peer-reviewed a journal, is adequately reliably sourced. The ordinary criterion for reliable sourcing is that the source be a secondary one, for example a respected textbook reporting other sources. At present, at a glance, it seems to me that the material is perhaps partly wrong because it does not agree with Kirchhoff's law; perhaps my first impression needs reconsideration.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 22:02, 20 January 2016 (UTC)
+I am trying to understand black bodies (bb), not being a physicist.  This article, like others I have read, talks about absorption and emissions of radiation. Absorption by a bb is defined to be 100% of incident radiation.  In the next sentence, at the beginning, we are told that a bb emits radiation.  Confusingly, that suggests that absorption is not 100%; some is going back out.  Emission qualities depend on the temperature.  Is the temperature determined by the absorbed radiation?  Or just by an independent local heat source? Is the thermal capacity of the bb relevant to heating caused by absorbed radiation? Is the relevance of a bb to physics because it absorbs, it emits, or both?  Or is it because it transforms incident radiation into outgoing radiation with different properties dependent on its temperature which is determined by what?? Any clarifications would be appreciated. [[User:KPD674|KPD674]] ([[User talk:KPD674|talk]]) 11:35, 17 August 2024 (UTC)
-Ah, I see! My undo has been undone, 25 minutes after my undo. Evidently the undoer, the original poster, was so enthusiastic that he did not wait to read my talk-page reasons, which took me 32 minutes to write. Because that shows that the poster is new to Wikipedia editing, I will forbear for the moment from undoing his undo, so as to give him the opportunity to undo it himself. Anyhow, the original post will not stand. I suggest the poster, Editor IP [[User:194.136.94.25|194.136.94.252]], carefully read and consider my above talk-page reasons, and take advantage of my forbearance in not myself undoing his undo.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 22:17, 20 January 2016 (UTC)
-:I concur and have again removed the content from the lead. For something that necessitates the rewriting of long-standing, well-known laws of physics, we can wait until textbooks with the rewritten law have been published - or, at the very least, until secondary sources confirm the result. [[User:Huon|Huon]] ([[User talk:Huon|talk]]) 07:52, 21 January 2016 (UTC)
-== External links modified ==
-Hello fellow Wikipedians,
-I have just modified one external link on [[Black body]]. Please take a moment to review [https://en.wikipedia.org/enwiki/w/index.php?diff=prev&oldid=791623419 my edit]. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit [[User:Cyberpower678/FaQs#InternetArchiveBot|this simple FaQ]] for additional information. I made the following changes:
-*Added archive https://web.archive.org/web/20130510184530/http://cosmos.asu.edu/publications/papers/ThermodynamicTheoryofBlackHoles%2034.pdf to http://cosmos.asu.edu/publications/papers/ThermodynamicTheoryofBlackHoles%2034.pdf
-When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
-{{sourcecheck|checked=false|needhelp=}}
-Cheers.—[[User:InternetArchiveBot|'''<span style="color:darkgrey;font-family:monospace">InternetArchiveBot</span>''']] <span style="color:green;font-family:Rockwell">([[User talk:InternetArchiveBot|Report bug]])</span> 12:38, 21 July 2017 (UTC)
-== White Body ==
-A Wikipedia Page On White Body And White Body Radiation [[User:Josemonfordindia|Josemonfordindia]] ([[User talk:Josemonfordindia|talk]]) 19:16, 9 December 2018 (UTC)