explain xkcd - User contributions [en]

2373: Chemist Eggs

2020-11-06T12:58:01Z

Mycroft: /* Trivia */

{{comic
| number = 2373
| date = October 16, 2020
| title = Chemist Eggs
| image = chemist_eggs.png
| titletext = Chemists actually find it simpler to define a general odor of rotten eggs as a baseline, and the LACK of rotten eggs as a distinct smell.
}}

==Explanation==

In this comic, [[Ponytail]] explains to [[Cueball]] that if he smells sulfides then the chemistry experiment on which they're working has failed. Ponytail then clarifies that sulfides smell like rotten eggs. The main and most distinct chemical rotten eggs emit is {{w|hydrogen sulfide}}, hence most people who smell them will link the chemical with "rotten egg smell".

Cueball replies, however, that he doesn't actually know what rotten eggs smell like, and it's odd that everyone uses that as a comparison. This is a result of changing times — decades ago, when the 'rotten eggs' descriptor became commonplace in chemistry education at high schools and universities, rotten eggs were indeed common enough that cooks avoided adding eggs directly to other ingredients, lest the rotten egg, not detected until after it was too late, force the cook to discard everything and start over. Vastly improved farming, shipping, and marketing practices have made the rotten egg vanishingly rare, at least at supermarkets in the USA. Moreover, much greater recognition of the health hazards of hydrogen sulfide means that, due to various occupational safety precautions, opportunities for sniffing the gas have become scarce, and usually engender swift reactions such as building evacuation.

Thus, the comparison has outlived the circumstances that spawned it, and chemistry teachers parrot a line they learned as students, which is no longer relevant to the students' experience. Cueball then takes the disconnect between the trope and his experience and pushes it for all it's worth. This could be taken as symbolic of people who spot such discordances and blow them out of proportion to troll others, in which case, Cueball has most definitely succeeded, based on how Ponytail reacts — she is clenching her fists in anger as she leaves the conversation, presumably to avoid further irritation. (Perhaps she smells eggs often from the people in [[382: Trebuchet]]!)

Some of [[Cueball]]'s questions suggest that chemists use eggs in place of other items. For example, the superstitious may react to a {{w|spilling salt|spilling of salt}} by picking it up and throwing it over their left shoulder, ostensibly as an attempt to blind the Devil. Another relates to the upcoming night before Halloween event called "{{w|Mischief Night}}", where kids are known to {{w|Egging|throw eggs}} at houses. Cueball asks Ponytail how she will know if this has happened, as he thinks she keeps an unsusually large numer of eggs in her house.

Even though rotten eggs (and hydrogen sulfide in general) are much less common nowadays, many fuel gases are mixed with odorant compounds to signal that a leak is happening; even if the user might be unfamiliar with "rotten eggs" specifically, a large amount of unpleasant odor still works as an alarm that something bad is happening. People who use natural gas or propane stoves should be familiar with the similarly rotten smell of {{w|methanethiol}}, {{w|ethanethiol}}, and/or {{w|tert-butylthiol}} (the "-SH" thiol group is a common feature of many pungent odors, including garlic and skunk spray). Some {{w|Mineral springs|mineral springs}} and other natural water sources also contain sulfides and have a strong sulfide odor and flavor; they are sometimes referred to as "sulfur springs".

The title text makes a joke about how often chemists use the comparison, saying that they use a rotten egg smell as the baseline, and that a lack of the smell is a distinct one. Given the health hazards of hydrogen sulfide and the regulations now enforced in recognition of those hazards, the chemistry teacher probably doesn't often experience the smell either. Since hydrogen sulfide deadens the sense of smell, taking this smell as a 'baseline' is improbable and potentially dangerous, and it's unfortunate that the title text makes this suggestion.

== Trivia ==
The amount of eggs eaten per person in the U.S was estimated at 289.5 in 2019. (Source:https://www.statista.com/statistics/183678/per-capita-consumption-of-eggs-in-the-us-since-2000/#:~:text=In%202019%2C%20consumption%20of%20eggs,by%20the%20total%20U.S.%20population.)

==Transcript==
:[Cueball and Ponytail face a table with something like a lab stirrer or heater on it, supporting a flat-bottomed and -topped container from which bubbles are rising.]
:Cueball: How will I know if the reaction fails?
:Ponytail: You'll smell the sulfides.
:Cueball: What do those smell like?
:Ponytail: Sulfurous. Rotten eggs.

:[A new panel, the table is gone. Cueball is now facing Ponytail.]
:Cueball: Chemists always compare sulfur to rotten eggs.
:Cueball: But why would I know that smell?
:Ponytail: I dunno, It's a common thing!

:[Ponytail puts her hand out.]
:Cueball: Is it? My kitchen is messy, but there aren't eggs lying around rotting.
:Ponytail: You must have smelled one at ''some'' point.

:[Ponytail is now walking right off-panel, away from Cueball. She is clenching her hands and is evidently annoyed]
:Cueball: Are all chemists' houses full of random raw eggs? Do you toss them over your shoulder for good luck?
:Ponytail: '''''My house is not full of eggs!'''''
:Cueball: What do you consider a normal amount of eggs in a house?
:Cueball: If kids egg your house this Halloween, how will you know??

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Chemistry]]
[[Category:Food]]

2373: Chemist Eggs

2020-11-06T12:57:04Z

Mycroft: /* Explanation */ Added trivia section along with fact about eggs eaten in the U.S.

{{comic
| number = 2373
| date = October 16, 2020
| title = Chemist Eggs
| image = chemist_eggs.png
| titletext = Chemists actually find it simpler to define a general odor of rotten eggs as a baseline, and the LACK of rotten eggs as a distinct smell.
}}

==Explanation==

In this comic, [[Ponytail]] explains to [[Cueball]] that if he smells sulfides then the chemistry experiment on which they're working has failed. Ponytail then clarifies that sulfides smell like rotten eggs. The main and most distinct chemical rotten eggs emit is {{w|hydrogen sulfide}}, hence most people who smell them will link the chemical with "rotten egg smell".

Cueball replies, however, that he doesn't actually know what rotten eggs smell like, and it's odd that everyone uses that as a comparison. This is a result of changing times — decades ago, when the 'rotten eggs' descriptor became commonplace in chemistry education at high schools and universities, rotten eggs were indeed common enough that cooks avoided adding eggs directly to other ingredients, lest the rotten egg, not detected until after it was too late, force the cook to discard everything and start over. Vastly improved farming, shipping, and marketing practices have made the rotten egg vanishingly rare, at least at supermarkets in the USA. Moreover, much greater recognition of the health hazards of hydrogen sulfide means that, due to various occupational safety precautions, opportunities for sniffing the gas have become scarce, and usually engender swift reactions such as building evacuation.

Thus, the comparison has outlived the circumstances that spawned it, and chemistry teachers parrot a line they learned as students, which is no longer relevant to the students' experience. Cueball then takes the disconnect between the trope and his experience and pushes it for all it's worth. This could be taken as symbolic of people who spot such discordances and blow them out of proportion to troll others, in which case, Cueball has most definitely succeeded, based on how Ponytail reacts — she is clenching her fists in anger as she leaves the conversation, presumably to avoid further irritation. (Perhaps she smells eggs often from the people in [[382: Trebuchet]]!)

Some of [[Cueball]]'s questions suggest that chemists use eggs in place of other items. For example, the superstitious may react to a {{w|spilling salt|spilling of salt}} by picking it up and throwing it over their left shoulder, ostensibly as an attempt to blind the Devil. Another relates to the upcoming night before Halloween event called "{{w|Mischief Night}}", where kids are known to {{w|Egging|throw eggs}} at houses. Cueball asks Ponytail how she will know if this has happened, as he thinks she keeps an unsusually large numer of eggs in her house.

Even though rotten eggs (and hydrogen sulfide in general) are much less common nowadays, many fuel gases are mixed with odorant compounds to signal that a leak is happening; even if the user might be unfamiliar with "rotten eggs" specifically, a large amount of unpleasant odor still works as an alarm that something bad is happening. People who use natural gas or propane stoves should be familiar with the similarly rotten smell of {{w|methanethiol}}, {{w|ethanethiol}}, and/or {{w|tert-butylthiol}} (the "-SH" thiol group is a common feature of many pungent odors, including garlic and skunk spray). Some {{w|Mineral springs|mineral springs}} and other natural water sources also contain sulfides and have a strong sulfide odor and flavor; they are sometimes referred to as "sulfur springs".

The title text makes a joke about how often chemists use the comparison, saying that they use a rotten egg smell as the baseline, and that a lack of the smell is a distinct one. Given the health hazards of hydrogen sulfide and the regulations now enforced in recognition of those hazards, the chemistry teacher probably doesn't often experience the smell either. Since hydrogen sulfide deadens the sense of smell, taking this smell as a 'baseline' is improbable and potentially dangerous, and it's unfortunate that the title text makes this suggestion.

== Trivia ==
In 2019, consumption of eggs in the United States was estimated at 289.5 per person
The amount of eggs eaten per person in the U.S was estimated at 289.5 in 2019. (Source:https://www.statista.com/statistics/183678/per-capita-consumption-of-eggs-in-the-us-since-2000/#:~:text=In%202019%2C%20consumption%20of%20eggs,by%20the%20total%20U.S.%20population.)

==Transcript==
:[Cueball and Ponytail face a table with something like a lab stirrer or heater on it, supporting a flat-bottomed and -topped container from which bubbles are rising.]
:Cueball: How will I know if the reaction fails?
:Ponytail: You'll smell the sulfides.
:Cueball: What do those smell like?
:Ponytail: Sulfurous. Rotten eggs.

:[A new panel, the table is gone. Cueball is now facing Ponytail.]
:Cueball: Chemists always compare sulfur to rotten eggs.
:Cueball: But why would I know that smell?
:Ponytail: I dunno, It's a common thing!

:[Ponytail puts her hand out.]
:Cueball: Is it? My kitchen is messy, but there aren't eggs lying around rotting.
:Ponytail: You must have smelled one at ''some'' point.

:[Ponytail is now walking right off-panel, away from Cueball. She is clenching her hands and is evidently annoyed]
:Cueball: Are all chemists' houses full of random raw eggs? Do you toss them over your shoulder for good luck?
:Ponytail: '''''My house is not full of eggs!'''''
:Cueball: What do you consider a normal amount of eggs in a house?
:Cueball: If kids egg your house this Halloween, how will you know??

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Chemistry]]
[[Category:Food]]

Design of xkcd.com

2020-10-19T19:52:12Z

Mycroft: /* Design */ It was just a typo. It said 'these can chance over time see below.' I corrected chance to 'change' and I added a comma after 'time'.

*Here the current design of the [[xkcd|xkcd.com]] front page (and other features of the page) is described.
**Changes will be mentioned below in the [[#Changes over time|Changes over time]] section

== Design ==
*The front page consist of four segments.
**They are all white areas split apart from each other with a light blue gray background color showing up in between them.
*The first segment:
**[[#xkcd links|xkcd links]]:
***It is the square one. It is at the top left of the page, with just a thin line of the background showing above it and below it and to its right.
***It contains links to other pages on xkcd [[#xkcd links|see below]].
*The second segment:
**[[#Header|Header]]
***This has the same height as the first segment but takes up a thin rectangle making those two first segments have the same total width from left to right as the two segments below. And the lines around it where the background can be seen is as in the previous segment.
***On a broad computer screen at full resolution and 100% zoom there will be broad bands of the background on each side of these centered segments.
***In this segment are the following items (see [[#Header|below]] for more on these)
****The logo of xkcd to the left. (The logo image is a link to xkcd.com, and will take you to the front page from other comics).
****Next to the logo to the right is an explanation of what the comic is about.
****And below these two there will be a changing message, the [[#Header text|header text]].
*The third segment:
**[[#Main comic|Main comic]]
***This is the main segment where the comics are. And on the front page the newest comic will always be displayed.
***So that this is changing three times a week is not considered a change to the front page design.!
***This segment is as broad as the two above together and as broad as the one below it has a rectangular shape most of the time, but is shapes it self after the [[482: Height|height]] of the comic.
****So it can be very short [https://www.xkcd.com/1123/ like here]] [[1123: The Universal Label]] and very long for instances [https://www.xkcd.com/1732/ like here] with [[1732: Earth Temperature Timeline]]
***See more [[#Main comic|below]].
***Around the entire segment there is a thin line where the background can be seen.
*The fourth segment:
**[[#Bottom segment|Bottom segment]]
***This is the final segment below the main comic segment. It is just as wide as that above but has a fixed dimension.
***The first is a line of five [[#Footer comics|Footer comics]]. These can change over time, see below.
***Beneath is a link to two [[#Feeds|feeds]].
***Beneath these is a list [[#Comics I enjoy|Comics I enjoy]]
***Beneath these there is a footnote.
****Previously there also been a Warning, but this has been removed and the footnote changed shortly thereafter.
****See [[#Warning and footnote|Warning and footnote]]
***Finally there is the [[#License and copyright|License and copyright]] statements at the very bottom.
***Beneath that there is an empty white part and then the bottom of the page is reached.
****Only the shadow of this last segments edge can be seen at the bottom, the background color is not visible below.

== xkcd links ==
*Below are the links at the top left of the page to navigate around on xkcd.com
**If they change then make a note of what they where in the past (with webarchive link if possible)
*[https://xkcd.com/archive/ Archive]
*[https://what-if.xkcd.com/ What If?]] (see [[what if|what if?]])
*[https://blog.xkcd.com/ Blag]] (see [[Blag]]: The Blag of the webcomic).
*[https://store.xkcd.com/ Store]
*[https://xkcd.com/about/ About]
*[https://xkcd.com/atom.xml Feed •] (The atom feed that has long been in the [[#Feeds|feeds]] below the footer comics.
*[https://xkcd.com/newsletter/ Email] (add you e-mail address and subscribe "To receive the comic and news postings in your inbox").

====Changes to the links====
*On [http://web.archive.org/web/20190611031920/https://xkcd.com/ 2019-06-11], as the [[xkcd Header text|header text]] changed to announce the [[xkcd_Header_text#2019-06-11|''How To'' book tour]], two new links was also added to the xkcd links.
**The [https://xkcd.com/atom.xml Feed •] which is an XML file showing some details about the most recent comics.
**[https://xkcd.com/newsletter/ Email] where people can subscribe to news.
***The day before, [http://web.archive.org/web/20190610024415/https://xkcd.com/ 2019-06-10], only the original five links were present.
*On [http://web.archive.org/web/20120427150443/http://xkcd.com/ 2012-04-27] while [[1048: Emotion]] was up the five links changed to be listed in the current one column style.
*On [http://web.archive.org/web/20120403082844/http://xkcd.com:80/ 2012-04-03] while [[1037: Umwelt]] was on the front page the links is written in two columns rather than in one.
**This lasted until [http://web.archive.org/web/20120425220409/http://xkcd.com:80/ 2012-04-25] while [[1047: Approximations]] was up.
*Before this there are a period on the web archive where the comic has bot been store properly.
*But all the way back to the start of the current design on [http://web.archive.org/web/20060710090528/http://www.xkcd.com/ 2006-07-10] there where five links in one column. They where not the same as today, but not that far off:
**About
**News
**Forums
**RSS Feed
**Store

== Header ==
*The header consist of:
**The logo:
***The four letters x k c and d are there in a gray blue color in front/on top of a faded out drawing in similar color:
***A table with a shining old and big computer screen is behind the x, the rest of the table and an office chair at the end of the table behind the k, a guy with thin dark hair (resembling an early version of [[Hairy]]) behind the c and finally [[Black Hat]] behind the d. The two are facing each other, so Hairy has his back to the table. The line in the d goes straight up through the stick figure body of Black Hat ending in his round head just below the Black Hat.
**A description of the comic next to the logo in two lines that says:
***''A webcomic of romance,''
***''sarcasm, math, and language.''
****See the [[xkcd warning]] (which now is gone from xkcd pages).
**Beneath all this there is some kind of message the [[xkcd Header text|Header text]] which may change over time.
***The go to header text is: '''xkcd updates every Monday, Wednesday, and Friday.'''
***But the [[xkcd_Header_text#Current_header_text|current header text]] may be different.
***See main article: [[xkcd Header text]].

== Main comic ==
*This is where the comics are displayed.
**Above the comic is the title in large bold letters.
***As always Randall uses a small caps font. By copying text to another program without the font, it shows as normal letters with both capital and normal letters.
**Below the title and above the main comic image there is a row of buttons. These are fairly standard:
***The two outermost with "arrow all the way back" <nowiki>|<</nowiki> or <nowiki>>|</nowiki> takes the user to either the first or the latest comic.
***Next to those are the ''< Previous'' and the ''Next >'' buttons taking the user to the two nearest comics to the one displayed.
***In the middle is the ''Random'' button comic which chooses a random comic.
****If the user is on the main page, the two buttons that points to the right will not do anything as the newest comic is displayed already.
***The same buttons are also beneath the comic.
**The comic is thus between these two rows of buttons. For smaller comics this is not so relevant, but for longer big comics the buttons is at hand when only one row can be seen either at the top or at the bottom.
**Finally beneath the second row of bottoms there are two links.
***The first is a permalink to the current comic displayed on the page.
***Permalink is also used in some of xkcd's interactive comics see the [[1350:_Lorenz#Permalink|permalink section]] on [[1350: Lorenz]].
***The link is just the home address with the number of the comic behind. So for the newest comic as of this post [[1791: Telescopes: Refractor vs Reflector]], the link would just be:
****https://www.xkcd.com/1791/
***The other link is:
****The image URL (for hotlinking/embedding):
****http://imgs.xkcd.com/comics/telescopes_refractor_vs_reflector.png
***Here the link is also on xkcd but under comics and with the comics title instead of the number, and then with the extension for the .png file at the end.

== Bottom segment ==
*An image can be found [[:Category:Footer_comics#Image of current footer comics|here]] on the footer comics page.
==== Footer comics ====
*Five [[:Category:Footer comics|footer comics]] has been used at the bottom of xkcd almost from the beginning after only xkcd.com was used to post comics.
*They are likely selected to give a broad specter of the content and most likely are to some of Randall's own favorites (or users favorites).
*They have changed at least twice since the first was used back in February 2006 before they changed a third time to the current five comics in August 2010.
*They changed for the fourth time on 1 March 2019 to the present version with [[Earth Temperature Timeline]] in addition to the five previous comics.

==== Feeds ====
*There are links to two xkcd feeds below the footer comics. And on [http://web.archive.org/web/20190206060904/https://xkcd.com/ 2019-02-06] also a link to ''Email'', where it is possible to subscribe for news, was added.
**[https://www.xkcd.com/rss.xml RSS Feed]
**[https://www.xkcd.com/atom.xml Atom Feed]
**[https://xkcd.com/newsletter/ Email]
***The two last links have later, on [http://web.archive.org/web/20190611031920/https://xkcd.com/ 2019-06-11], been added to the [[#xkcd_links|links]] at the top.
***Before, from [http://web.archive.org/web/20190205050302/https://xkcd.com/ 2019-02-05], only the two feeds where added here.

==== Comics I enjoy ====
*Beneath the two feeds there is a list of Randall's favorite webcomics with links
*Comics I enjoy:
#[http://threewordphrase.com/ Three Word Phrase]
#[http://www.smbc-comics.com/ SMBC]
#[http://www.qwantz.com/ Dinosaur Comics]
#[http://oglaf.com/ Oglaf] (nsfw)
#[http://www.asofterworld.com/ A Softer World]
#[http://buttersafe.com/ Buttersafe]
#[http://pbfcomics.com/ Perry Bible Fellowship]
#[http://questionablecontent.net/ Questionable Content]
#[http://www.buttercupfestival.com/ Buttercup Festival]
#[http://www.mspaintadventures.com/?s=6&p=001901 Homestuck]
#[http://www.jspowerhour.com/ Junior Scientist Power Hour]

==== Other Things ====
*Beneath the web comic links is another section of external writings.
*Since [http://web.archive.org/web/20190226192426/https://xkcd.com/ 2019-02-26] there have been three links under the text "Other things:"
**[https://medium.com/civic-tech-thoughts-from-joshdata/so-you-want-to-reform-democracy-7f3b1ef10597 Tips on technology and government]
**[https://www.nytimes.com/interactive/2017/climate/what-is-climate-change.html Climate FAQ]
**[https://twitter.com/KHayhoe Katharine Hayhoe]
***The two bottom links replaced the two original links from when this section began.
*On [http://web.archive.org/web/20170715021703/https://xkcd.com/ 2017-07-15] a third link was added to the two original:
**[http://womenalsoknowstuff.com/ Women Also Know Stuff]
**[https://techsolidarity.org/ Tech Solidarity]
**[https://medium.com/civic-tech-thoughts-from-joshdata/so-you-want-to-reform-democracy-7f3b1ef10597 Tips on technology and government]
***The two original links was removed in favor of two other links after [http://web.archive.org/web/20190225185416/https://xkcd.com/ 2019-02-25].
***The new link then moved to the top.
*On [http://web.archive.org/web/20170321030609/https://xkcd.com/ 2017-03-21] this section became part of xkcd with two links:
**[http://womenalsoknowstuff.com/ Women Also Know Stuff]
**[https://techsolidarity.org/ Tech Solidarity]
***There where only two links until [http://web.archive.org/web/20170714015753/https://xkcd.com/ 2017-07-14]. The day after a third link was added.
*Up until [http://web.archive.org/web/20170320025830/https://xkcd.com/ 2017-03-20] this section was not a part of the xkcd design.

==== Warning and footnote ====
At the bottom of the xkcd page there was a [[xkcd warning|warning]] for most of the first ten and a half years, and below that there was, since 2007 a [[footnote]]. Both has been removed, but a new footnote has appeared. See the links for more information.

==== License and copyright ====
*Randall allows people to use his comics for free as long as they do not make money on them and as long as they credit him with the work.
*There are two notes:
**This work is licensed under a [http://creativecommons.org/licenses/by-nc/2.5/ Creative Commons Attribution-NonCommercial 2.5 License].
**This means you're free to copy and share these comics (but not to sell them). [https://www.xkcd.com/license.html More details].
***The last link is to a link on xkcd.

== Changes over time ==
*The design has changed many times but mainly in the beginning.
**Below here is only meant to be a list of huge changes to the entire page.
**Preferably only changes that can be documented with a web archive link should be used.
**Give a date (in the correct format as shown in [[1340: Unique Date]]) of the link first and sort after newest at the top:
*2006-07-10
**This was the first time that a design [http://web.archive.org/web/20060710090528/http://www.xkcd.com/ close to the current] was used.
***[[126: Red Spiders Cometh]] was up at the time.
*2006-02-07
**This was [http://web.archive.org/web/20060207154349/http://www.xkcd.com/ how the web site looked] after Randall had closed down for LiveJournal releases the week before on January 30th 2006 (with the release of [[56: The Cure]]). The link is to the first copy on the web archive after that happened, and it was saved the day after [[60: Super Bowl]] was released.
*2006-01-09
**This was [http://web.archive.org/web/20060109071222/http://www.xkcd.com/ how the web sited looked] three days after the second comic, [[46: Secrets]], was released simultaneously [[:Category:Posted on LiveJournal after xkcd|on both LiveJournal and xkcd]]. The page was saved on the 9th of January 2006, before that days comic ([[47: Counter-Red Spiders]]) had been released. Randall had taken a long break from xkcd since and had just begun posting again on both sites from January 4th 2006 with [[45: Schrodinger]].
***The 41 comics released earlier throughout 2005 was at that time all included on the xkcd page as if they had been inserted on New Years day of 2006 (2006-01-01).
***Thus disregarding that, they had almost only been released using the still going Monday, Wednesday, Friday schedule from September 30th 2005, with the first being [[7: Girl sleeping (Sketch -- 11th grade Spanish class)|7: Girl sleeping]] and the last being [[39: Bowl]] released on December 5th 2005. Thus he took 30 days without a release from there and had released .
***And as would be clear he also disregarded the order as the first is now [[1: Barrel - Part 1]] (which was though released the same day as the Girl, but still only as number 3), and the last number of those 41 comics is now [[44: Love]], which thus also shows that three other comics have been inserted among the first 44 to make the first xkcd release number 45.

[[Category:Meta]]
[[Category:Design of xkcd]]