explain xkcd - User contributions [en]

2906: Earth

2024-03-14T03:50:16Z

172.69.194.183: /* Explanation */ Prior art.

{{comic
| number = 2906
| date = March 13, 2024
| title = Earth
| image = earth_2x.png
| imagesize = 364x472px
| noexpand = true
| titletext = Just think of all the countless petty squabbles and misunderstandings, of all the fervent hatreds, over so insignificant a thing as the direction and duration of a rocket engine firing.
}}

==Explanation==
{{incomplete|Created by a MEANINGLESS PALE BLUE DOT FLOATING IN SPACE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

At first sight, this appears to be the famous {{w|Carl Sagan}} commentary, upon the ''{{w|Pale Blue Dot}}'' image of Earth, a picture taken by the {{w|Voyager 1 probe}} in 1990 (at that time 6 billion kilometers away) but having been transmitted back to Earth to be appreciated as one of the most iconic 'photos of Earth from space', along with ''{{w|Earthrise}}'' and ''{{w|The Blue Marble}}''. Sagan's written, and later spoken, words evoke how the lives of all of us are somehow confined to barely more than a single pixel's-worth of existence.

From the comment, however, it appears that 'Carl' is not looking at an image. Instead it is a spacecraft window. The minute nature of the Earth is as a result of some unintended consequences of deorbitting manouever from {{w|Low Earth orbit}} (i.e. not more than 2000 kilometers from the Earth's surface, from which the Earth should still mostly fill any view that points towards it). Rather than transitioning from LEO into a re-entry trajectory, somehow the vessel and crew have been sent into a ''much'' higher-reaching orbit, if not into a solar or extra-solar trajectory. And it is Carl's fault. The speech is thus not an abstract description of where we all are, but pointing out where all the crew (unwillingly, and against all recent expectations) are ''not''.

The title text continues with the traditional tone of the speech, only to become an implicit attempt to claim that it wasn't quite as drastic an error as it actually seems to have been.

The very same words (or as far as they go), but in the more traditional situation of an informative lecture, were previously used in [[1246: Pale Blue Dot]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Carl Sagan standing in front of the Pale Blue Dot from far away with his right hand pointed toward the image.]
:Carl Sagan: Look again at that dot. That's home. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives...
:Carl Sagan: On a mote of dust suspended in a sunbeam.
:Off-panel voice: We '''know,''' Carl.

:[Caption below the panel:]
:Carl Sagan was '''''not''''' making us feel better about how badly he'd messed up the low Earth orbit reentry burn.

{{comic discussion}}

[[Category:Space]]
[[Category:Comics featuring real people]]

1335: Now

2024-02-22T12:51:50Z

172.69.194.183:

{{comic
| number = 1335
| date = February 26, 2014
| title = Now
| image = now.gif
| titletext = This image stays roughly in sync with the day (assuming the Earth continues spinning). Shortcut: xkcd.com/now
}}
*The image above is accelerated to show a full day's spin in a few seconds. The actual comic completes one revolution per day.
*For the current state, see [http://xkcd.com/now/ xkcd.com/now].

==Explanation==
{{incomplete|reason There seems to be a debate about how far {{w|Moscow Time}} is. Russians(and Google https://www.bing.com/search?q=how+many+hours+ahead+is+moscow&cvid=69d040ed36e7433aa547f24dd2dd50d6&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIGCAEQABhAMgYIAhAAGEAyBggDEAAYQDIGCAQQABhAMgYIBRAAGEAyBggGEAAYQDIGCAcQABhAMgYICBAAGEAyBwgJEEUY_FXSAQkxNjk2MGowajGoAgCwAgA&FORM=ANAB01&DAF0=1&PC=U531 + timeanddate.com https://www.timeanddate.com/time/zone/russia/moscow) say that it is UTC+3:00, but others say it is UTC+4:00; who is correct?}}

The picture is divided in 24 segments representing the 24 hours of the day. At noon and at midnight the break between segments is indicated by the tip of a dark grey triangle.

The picture rotates by 3.75 {{w|degree (angle)|degrees}} every 15 minutes, as does the Earth, so that it is constantly up to date in showing which regions are currently at which times of day. The picture change seems to happen half-way through a 15-minute time increment (that is, at 7½, 22½, 37½, and 52½ minutes after each hour), so that the picture is always correct for the nearest multiple of 15 minutes.

The map projection of the earth in the middle of the picture shows an {{w|azimuthal equidistant projection}} with the {{w|South Pole}} in the center. This is unusual, as the projection typically puts the north pole in the center, but necessary in order for it to rotate clockwise. [[Randall]] was playing on projections before in [[977: Map Projections]].

The list of cities and countries doesn't match the map exactly - notice how the continent of Australia is shifted counterclockwise of the words "most Australian cities". This is because the map is centered relative to the {{w|time zone}}s and the local variations therein. The map shows the configuration of time zones with respect to {{w|daylight saving time}} (also known as summer time) at the time of the comic's initial release (February 2014); it was being observed in parts of Australia, New Zealand, Brazil, and other countries not named in this comic. If the map were to stay accurate through the year, the location of place names would have to move over the next few months as parts of the southern hemisphere went off DST and parts of the northern hemisphere went onto it; however, the map failed to change on the morning of March 9 as it should have (to recognize the start of DST in North America).

In many countries "{{w|business hours}}" are considered to be from 9 am to 5 pm. With some exceptions, including emergencies, it is generally considered rude to place a {{w|telephone}} call to someone's residence during the hours when most people are asleep; Randall portrays this time period as extending from 10 pm to 8 am. This may be a reference to the 10 pm "cutoff" time [http://www.youtube.com/watch?v=L0WeQJW-H3Y discussed] in an episode of "Curb Your Enthusiasm."

"Rude to Call" was also the name used by a G-mail experimental opt-in feature in 2009 which added a crossed out phone symbol next to the sender if it was night in the sender's time zone when the reader loaded the email on their screen.

On midnight at UTC we can see this situation:
*00:00 UTC {{w|Greenwich Mean Time}}
::UK, Portugal
::West Africa
*01:00 UTC {{w|Central European Time}}
::Most of central Europe
::Nigeria, and many more countries belonging to the {{w|West Africa Time}} zone
*02:00 UTC {{w|Eastern European Time}}
::Eastern Europe, many countries like Bulgaria, Romania or Greece
::The {{w|Levant}}
::Egypt
*03:00 UTC {{w|UTC+03:00}} (East Africa Time, Eastern Europe Forward Time, and Arabia Standard Time)
::Ethiopia, Kenya, Madagascar, Somalia, and more
::Kaliningrad and Belarus
::Iraq, Kuwait, Saudi Arabia, and more.
::Iran is at {{w|Iran Standard Time}}, using an offset of UTC+03:30
*04:00 UTC {{w|UTC+04:00}}
::{{w|Moscow Time}} (became UTC+03:00 on 26 October 2014, a couple of years after the publication of this comic)
::United Arab Emirates, Mauritius, and more
::Afghanistan is at {{w|Time in Afghanistan}}, using an offset of UTC+04:30
::Iran is at {{w|Iran Standard Time}}, using an offset of UTC+03:30
*05:00 UTC {{w|UTC+05:00}}
::Pakistan, Western Australia, Maldives and some France former colonies.
::Afghanistan is at {{w|Time in Afghanistan}}, using an offset of UTC+04:30
::India and Sri Lanka using {{w|UTC+05:30}}
::Nepal is using a much more odd offset at {{w|UTC+05:45}}
*06:00 UTC {{w|UTC+06:00}}
::Bangladesh, Bhutan...
::UK {{w|British Indian Ocean Territory}}
::Russia at {{w|Yekaterinburg Time}}, also Kazakhstan and Kyrgyzstan
::China only use {{w|Time in China|one time zone}} (+08:00) but Xinjiang and Tibet unofficially use +06:00
::India and Sri Lanka using {{w|UTC+05:30}}
::Nepal is using a much more odd offset at {{w|UTC+05:45}}
*07:00 UTC {{w|UTC+07:00}}
::South-east Asia like Cambodia, Indonesia, Thailand, Vietnam, and more
::Christmas Island belonging to Australia
::Russia is also using the {{w|Omsk Time}}
*08:00 UTC {{w|UTC+08:00}}
::Western Australia
::China uses only {{w|Time in China|one time zone}} while the country spans about five.
::Singapore
::Philippines
::Perth
*09:00 UTC {{w|UTC+09:00}}
::Japan
::The Koreas
*10:00 UTC {{w|UTC+10:00}}
::Brisbane and the Australian Capital Territory, New South Wales, Queensland, Tasmania and Victoria
::US: Guam and Northern Mariana Islands
*11:00 UTC {{w|UTC+11:00}}
::Micronesia, New Caledonia, Solomon Islands, Vanuatu
::Russia {{w|Vladivostok Time}}
*12:00 UTC {{w|UTC+12:00}} or {{w|UTC−12:00}}
::Kamchatka (a Russian peninsula at the east Siberia), Kiribati, Marshall Islands, Nauru, Tuvalu and more
*13:00 UTC {{w|UTC+13:00}} or {{w|UTC−11:00}}
::New Zealand, Kiribati, Tonga
*14:00 UTC {{w|UTC+14:00}} or {{w|UTC−10:00}}
::Hawaii, Samoa
::French Polynesia, Cook Islands, and more
::Line Islands, belonging to Kiribati
*15:00 UTC {{w|UTC−09:00}}
::{{W|Time in Alaska|Alaska}} (some islands of Alaska is at -10:00 and a few city's are at -08:00)
::French Polynesia
*16:00 UTC {{w|UTC−08:00}} or {{w|Pacific Time Zone}}
::US West Coast
::Canada or (British Columbia and Yukon)
::Mexico (Baja California)
*17:00 UTC {{w|UTC−07:00}} or {{w|Mountain Time Zone}}
::US: Denver, and much more
::Canada: Alberta (Calgary, Edmonton), British Columbia, more
*18:00 UTC {{w|UTC−06:00}} or {{w|Central Time Zone}}
::Mexico, Chile, Ecuador, Nicaragua and more
::US: Chicago, Texas except of some most westernmost counties, and many more
*19:00 UTC {{w|UTC−05:00}} or {{w|Eastern Time Zone}}
::Eastern Canada like Ontario or Quebec
::US East Coast including New York and Florida.
::But also Cuba, Haiti, Panama and much more countries
*20:00 UTC {{w|UTC−04:00}} or {{w|Atlantic Time Zone}}
::Canadian Maritimes: New Brunswick, Prince Edward Island, Nova Scotia. (Newfoundland uses {{w|UTC-03:30}})
::Chile
::Greenland
::Most of the Caribbean Islands.
*21:00 UTC {{w|UTC−03:00}}
::Coastal Brazil, Argentina, Uruguay, French Guiana, the UK Falkland Islands, and more
*22:00 UTC {{w|UTC−02:00}}
::UK: South Georgia and the South Sandwich Islands
::Brazil: Fernando de Noronha
*23:00 UTC {{w|UTC−01:00}}
::Cape Verde
::Azores (part of Portugal)

==Technical notes==
When first posted, the picture was exactly 12 hours off. Somewhere around 5:10 UTC, this was fixed. The original version also included a listing for Inland Brazil; this could have created a conflict with US East Coast when Daylight-Saving Time begins in the US, and it has been removed.

The names used for the image files refer not to {{w|Universal Time|UTC (Universal Time)}} as one might expect but rather to the time exactly 12 hours off of that. The name of the image file linked from the page matched Universal Time during the first few hours, but the file-naming scheme did not change when the comic was corrected.

==Transcript==
:[The comic is a moving circle with a static outer ring.]

:[The outermost part of the static ring is divided in 22 segments representing the 24 hours of the day. The Noon (11 AM - 1 PM) and Midnight (11 PM - 1 AM) segments cover two hours which are not segmented. The ring is divided so it is yellow from 6 AM to 6 PM and dark grey on the other half.]
::Noon - 6 PM - Midnight - 6 AM

:[The innermost part of the static ring is light grey and divided in two sections that cower from 9 AM to 5 PM and from 10 PM to 8 AM respectively. They contain descriptions of the time intervals.]
::Business hours (9-5)
::Rude to call

:[The rest of the image consist of a rotating part.]

:[On the innermost part of the circle is the Earth as seen from the south pole. Each continent has a different color. The colors are
:*Europe: Red
:*Africa: Cyan
:*Asia: Green
:*Oceania: Purple
:*North America: Blue-violet
:*South America: Olive green
:*Antarctica (The south pole): Light grey

:[Two segmented rings circle the map - these give the names of the continents (not the Antactica) and the color of the ring match the color of the continent on the map. Each segment cover the part of the map with the given continent. The one with Europe is merged with the one for Asia - and the color also merges from red to green along Turkey and Russia where the transition from Europe to Asia occurs.]

:[On the inner ring are the names of the following continents (white text on a segment with the color of the continent)]
::Africa
::Oceania
::South America

:[On the second of these rings are the names of the following continents (white text on a segment with the color of the continent)]
::Europe Asia
::North America

:[On the outermost ring of the moving circle are written names of regions, countries and cities of the Earth over the part of the map in which time zone they belong. All the text is color coded to match the color of the continent they belong to as given on the central map. The text is written in four lines. Below the names are sorted by color and reading from left to right first - and only sorting top to bottom if needed.]

:[Europe - Red text:]
::UK - Most of Europe - Eastern Europe

:[Africa - Cyan text:]
::West Africa - Nigeria - Egypt - East Africa

:[Asia - Green text:]
::The Levant - Iraq - Iran - Moscow - Afghanistan - Pakistan - India - Southeast Asia - Java - China - Singapore - Philippines - Japan - The Koreas - Kamchatka

:[Oceania - Purple text:]
::Perth - Brisbane - Most Australian cities - New Zealand

:[North America - Blue-violet text:]
::Alaska - US West Coast - Denver - Mexico - Chicago - Texas - Eastern Canada - US East coast - Canadian Maritimes

:[South America - Olive green text:]
:: Coastal Brazil

==Implementations==
There are currently several implementations of the Now comic available for several different platforms:

Windows:
:A [https://github.com/leipert/xkcd-now-clock script] that automatically updates the wallpaper for the current time.

Linux:
:A [https://github.com/151henry151/randall-clock-desktop-background bash script] that automatically updates the wallpaper for the current time, written for a Debian system running i3. May work well for other linux distributions as well.

Android:
:An [https://play.google.com/store/apps/details?id=net.phillab.xkcd_now Android widget] version of the comic.

Cross-Platform:
:An [https://github.com/BruceJohnJennerLawso/xkcd-Now/releases/tag/1.02 offline version of the comic] made using C++ and SFML.

==Timed Links==
{| class="wikitable"
|+ Links to each individual comic image
|-
!00h!!01h!!02h!!03h!!04h!!05h
|-
|[http://imgs.xkcd.com/comics/now/00h00m.png 00h00m] [http://imgs.xkcd.com/comics/now/00h15m.png 00h15m] [http://imgs.xkcd.com/comics/now/00h30m.png 00h30m] [http://imgs.xkcd.com/comics/now/00h45m.png 00h45m]
|[http://imgs.xkcd.com/comics/now/01h00m.png 01h00m] [http://imgs.xkcd.com/comics/now/01h15m.png 01h15m] [http://imgs.xkcd.com/comics/now/01h30m.png 01h30m] [http://imgs.xkcd.com/comics/now/01h45m.png 01h45m]
|[http://imgs.xkcd.com/comics/now/02h00m.png 02h00m] [http://imgs.xkcd.com/comics/now/02h15m.png 02h15m] [http://imgs.xkcd.com/comics/now/02h30m.png 02h30m] [http://imgs.xkcd.com/comics/now/02h45m.png 02h45m]
|[http://imgs.xkcd.com/comics/now/03h00m.png 03h00m] [http://imgs.xkcd.com/comics/now/03h15m.png 03h15m] [http://imgs.xkcd.com/comics/now/03h30m.png 03h30m] [http://imgs.xkcd.com/comics/now/03h45m.png 03h45m]
|[http://imgs.xkcd.com/comics/now/04h00m.png 04h00m] [http://imgs.xkcd.com/comics/now/04h15m.png 04h15m] [http://imgs.xkcd.com/comics/now/04h30m.png 04h30m] [http://imgs.xkcd.com/comics/now/04h45m.png 04h45m]
|[http://imgs.xkcd.com/comics/now/05h00m.png 05h00m] [http://imgs.xkcd.com/comics/now/05h15m.png 05h15m] [http://imgs.xkcd.com/comics/now/05h30m.png 05h30m] [http://imgs.xkcd.com/comics/now/05h45m.png 05h45m]
|-
!06h!!07h!!08h!!09h!!10h!!11h
|-
|[http://imgs.xkcd.com/comics/now/06h00m.png 06h00m] [http://imgs.xkcd.com/comics/now/06h15m.png 06h15m] [http://imgs.xkcd.com/comics/now/06h30m.png 06h30m] [http://imgs.xkcd.com/comics/now/06h45m.png 06h45m]
|[http://imgs.xkcd.com/comics/now/07h00m.png 07h00m] [http://imgs.xkcd.com/comics/now/07h15m.png 07h15m] [http://imgs.xkcd.com/comics/now/07h30m.png 07h30m] [http://imgs.xkcd.com/comics/now/07h45m.png 07h45m]
|[http://imgs.xkcd.com/comics/now/08h00m.png 08h00m] [http://imgs.xkcd.com/comics/now/08h15m.png 08h15m] [http://imgs.xkcd.com/comics/now/08h30m.png 08h30m] [http://imgs.xkcd.com/comics/now/08h45m.png 08h45m]
|[http://imgs.xkcd.com/comics/now/09h00m.png 09h00m] [http://imgs.xkcd.com/comics/now/09h15m.png 09h15m] [http://imgs.xkcd.com/comics/now/09h30m.png 09h30m] [http://imgs.xkcd.com/comics/now/09h45m.png 09h45m]
|[http://imgs.xkcd.com/comics/now/10h00m.png 10h00m] [http://imgs.xkcd.com/comics/now/10h15m.png 10h15m] [http://imgs.xkcd.com/comics/now/10h30m.png 10h30m] [http://imgs.xkcd.com/comics/now/10h45m.png 10h45m]
|[http://imgs.xkcd.com/comics/now/11h00m.png 11h00m] [http://imgs.xkcd.com/comics/now/11h15m.png 11h15m] [http://imgs.xkcd.com/comics/now/11h30m.png 11h30m] [http://imgs.xkcd.com/comics/now/11h45m.png 11h45m]
|-
!12h!!13h!!14h!!15h!!16h!!17h
|-
|[http://imgs.xkcd.com/comics/now/12h00m.png 12h00m] [http://imgs.xkcd.com/comics/now/12h15m.png 12h15m] [http://imgs.xkcd.com/comics/now/12h30m.png 12h30m] [http://imgs.xkcd.com/comics/now/12h45m.png 12h45m]
|[http://imgs.xkcd.com/comics/now/13h00m.png 13h00m] [http://imgs.xkcd.com/comics/now/13h15m.png 13h15m] [http://imgs.xkcd.com/comics/now/13h30m.png 13h30m] [http://imgs.xkcd.com/comics/now/13h45m.png 13h45m]
|[http://imgs.xkcd.com/comics/now/14h00m.png 14h00m] [http://imgs.xkcd.com/comics/now/14h15m.png 14h15m] [http://imgs.xkcd.com/comics/now/14h30m.png 14h30m] [http://imgs.xkcd.com/comics/now/14h45m.png 14h45m]
|[http://imgs.xkcd.com/comics/now/15h00m.png 15h00m] [http://imgs.xkcd.com/comics/now/15h15m.png 15h15m] [http://imgs.xkcd.com/comics/now/15h30m.png 15h30m] [http://imgs.xkcd.com/comics/now/15h45m.png 15h45m]
|[http://imgs.xkcd.com/comics/now/16h00m.png 16h00m] [http://imgs.xkcd.com/comics/now/16h15m.png 16h15m] [http://imgs.xkcd.com/comics/now/16h30m.png 16h30m] [http://imgs.xkcd.com/comics/now/16h45m.png 16h45m]
|[http://imgs.xkcd.com/comics/now/17h00m.png 17h00m] [http://imgs.xkcd.com/comics/now/17h15m.png 17h15m] [http://imgs.xkcd.com/comics/now/17h30m.png 17h30m] [http://imgs.xkcd.com/comics/now/17h45m.png 17h45m]
|-
!18h!!19h!!20h!!21h!!22h!!23h
|-
|[http://imgs.xkcd.com/comics/now/18h00m.png 18h00m] [http://imgs.xkcd.com/comics/now/18h15m.png 18h15m] [http://imgs.xkcd.com/comics/now/18h30m.png 18h30m] [http://imgs.xkcd.com/comics/now/18h45m.png 18h45m]
|[http://imgs.xkcd.com/comics/now/19h00m.png 19h00m] [http://imgs.xkcd.com/comics/now/19h15m.png 19h15m] [http://imgs.xkcd.com/comics/now/19h30m.png 19h30m] [http://imgs.xkcd.com/comics/now/19h45m.png 19h45m]
|[http://imgs.xkcd.com/comics/now/20h00m.png 20h00m] [http://imgs.xkcd.com/comics/now/20h15m.png 20h15m] [http://imgs.xkcd.com/comics/now/20h30m.png 20h30m] [http://imgs.xkcd.com/comics/now/20h45m.png 20h45m]
|[http://imgs.xkcd.com/comics/now/21h00m.png 21h00m] [http://imgs.xkcd.com/comics/now/21h15m.png 21h15m] [http://imgs.xkcd.com/comics/now/21h30m.png 21h30m] [http://imgs.xkcd.com/comics/now/21h45m.png 21h45m]
|[http://imgs.xkcd.com/comics/now/22h00m.png 22h00m] [http://imgs.xkcd.com/comics/now/22h15m.png 22h15m] [http://imgs.xkcd.com/comics/now/22h30m.png 22h30m] [http://imgs.xkcd.com/comics/now/22h45m.png 22h45m]
|[http://imgs.xkcd.com/comics/now/23h00m.png 23h00m] [http://imgs.xkcd.com/comics/now/23h15m.png 23h15m] [http://imgs.xkcd.com/comics/now/23h30m.png 23h30m] [http://imgs.xkcd.com/comics/now/23h45m.png 23h45m]
|}

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Dynamic comics]]
[[Category:Time]]

Talk:1102: Fastest-Growing

2024-02-06T22:23:37Z

172.69.194.183:

It's about Apple fanboys. [[Special:Contributions/62.195.79.12|62.195.79.12]]
: And how is that? [[Special:Contributions/173.44.98.247|173.44.98.247]] 05:52, 1 September 2012 (UTC)
What if I just started my own religion. Technically speaking it had 0 members, and then I joined it. Would this mean a growth of infinite percent? Also, a flaw with using percents is if a religion has one person, person a, and then person b joined it, it would have 100% growth. Then person b or a (doesn't matter which) leaves. The religion has increased by 100% and decreased by 50%. Now, you can't really add percentages, but I have just grown 50%! Ha! By adding no people! Then if the one tha left, comes and leaves again, I have grown by 100% this year. --[[Special:Contributions/98.221.139.80|98.221.139.80]]
:''Technically'', if you start your own religion, you start out with 1 member (yourself)... unless you invent a religion you don't actually believe in, and then suddenly, um, {{w|Drinking_the_Kool-Aid|drink the koolaid}}. ...;) -- [[User:IronyChef|IronyChef]] ([[User talk:IronyChef|talk]]) 15:37, 3 September 2012 (UTC)
::OK. I create the religion. Leave it, and come back. It has grown by ∞ %. --[[Special:Contributions/98.221.139.80|98.221.139.80]]
::: You left it? How do we know you weren't excommunicated? ;-) Also, along the lines of ''if a tree falls in the woods and nobody is around to hear it...'', if a religion has nobody following it, does't it cease to exist? BTW, ∞ is not a numerical quantity, so ∞ % isn't really possible, even if the growth is infinite. -- [[User:IronyChef|IronyChef]] ([[User talk:IronyChef|talk]]) 05:19, 5 September 2012 (UTC)
: The flaw is that a 100% growth means it is 100% + 100% = 200% times as many people, and a 50% loss is 100% - 50% = 50% times as many people. 200% * 50% = 100% if one person joins and leaves your religion. [[Special:Contributions/107.2.113.228|107.2.113.228]] 6:58, 28 October 2018 (UTC)
The xkcd religion! Nice one, Black Hat.--[[Special:Contributions/98.221.139.80|98.221.139.80]]

The "claims to be fastest-growing religion" Wikipedia page is now a redirect to {{w|Growth of religion}}. I would change the link in the explanation, but, I'm not sure which section it should go to. [[Special:Contributions/108.162.216.45|108.162.216.45]] 03:18, 23 November 2013 (UTC)
:I did update the link and moved it into the section Trivia. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:20, 23 November 2013 (UTC)

"It seems safe to assume he dislikes this type of missionary method."
Well, it does get pretty boring doing things the same way every night. [[User:Hppavilion1|Hppavilion1]] ([[User talk:Hppavilion1|talk]]) 04:32, 18 December 2016 (UTC)

I love how the character is named "Combover". Fitting. --[[User:JayRulesXKCD|'''JayRules''XKCD''' ]][[User talk:JayRulesXKCD|what's up?]] 18:12, 9 January 2017 (UTC)

What kind of missionary do you think "Combover" is? Looks like a mormon to me... --[[User:JayRulesXKCD|'''JayRules''XKCD''' ]][[User talk:JayRulesXKCD|what's up?]] 18:15, 9 January 2017 (UTC)

There's a couple (between 2 and 5) reasons why I don't think Combover is a Mormon. I looked it up—Mormon Missionaries always travel in pairs, but Combover doesn't appear to have any cohort. Also, the percentage mentioned doesn't correlate with Mormonism. Lastly, Mormon Missionaries teach lessons to prospective members before they join; they don't just say "join my religion because." If anyone else agrees with me, I think the references to Mormonism should be removed for these reasons. [[Special:Contributions/108.162.219.148|108.162.219.148]] 17:12, 2 July 2017 (UTC)

I'm new here, but I wanted to ask if someone can fix the link at the end to say the Church of Jesus Christ of latter day saints? I'm not sure how to without breaking the link, but it is incorrect and needs to be fixed. Additionally, The last comment is indeed correct about the reference to my religion, however the reference is not out of place and was a welcome sight. Thank you all for contributing so nicely. {{unsigned|SmallCorrector|17:17, 6 February 2024}}
:To teach you how, where there is a wikilink to a page "A Page On Wikipedia" using <code><nowiki>{{w|A Page On Wikipedia}}</nowiki></code>, you can give it "A Better Page On Wikipedia", instead, by <nowiki>{{w|A Better Page On Wikipedia}}</nowiki></code>, or "Different Text To Link With" as <nowiki>{{w|A Page On Wikipedia|Different Text To Link With}}</nowiki></code>.
:I checked where the "Mormon Missionary" link went to, in case it was a redirected page (I always prefer to send such links ''directly'' to the destination page). I found that ''they'' have called their own article by that name. An issue which you can always bring up on their own pages (assuming nobody has already). That page does start with the (I presume) proper and full nomenclature for the same, of course.
:Deciding that it would be dishonest to link to a "Mormon ..." page with the full/accurate name (it would look Ok until someone clicked on the link and finds themselves on the 'improperly named' page, and confusion could be had along the way), I hope you like my solution of appending the desired version, to cater for both those unfamiliar with the more formal term ''and'' those who deserve the right to expect it.
:...though maybe there's some even better way. You (now that you know how) or anyone else can try other things out, if wished. [[Special:Contributions/172.69.194.183|172.69.194.183]] 22:23, 6 February 2024 (UTC)

2889: Greenhouse Effect

2024-02-04T11:18:32Z

172.69.194.183: I saw that whole (perhaps awkward) original phrasing was removed, without comment, a couple of edits ago. Decided to have a go at my own summation of it, not really knowing if I should make it snappier or even more wordy, to help. (Settled on the latter.)

{{comic
| number = 2889
| date = February 2, 2024
| title = Greenhouse Effect
| image = greenhouse_effect_2x.png
| imagesize = 740x315px
| noexpand = true
| titletext = Once he had the answer, Arrhenius complained to his friends that he'd "wasted over a full year" doing tedious calculations by hand about "so trifling a matter" as hypothetical CO2 concentrations in far-off eras (quoted in Crawford, 1997).
}}

==Explanation==
{{incomplete|Created by CREATING CRETACEOUS PARK - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic has [[:Category:Climate change|climate change]] as its topic, a recurring theme on xkcd.

It depicts a timeline with three events:
*The advent of the {{w|Industrial Revolution}}, marked by the introduction of the {{w|Watt steam engine}} by {{w|James Watt}} in 1776
*The first quantitative prediction of the {{w|greenhouse effect}} by {{w|Arvid Högbom}} and {{w|Svante Arrhenius}} in 1896
*And present day, early 2024.

The distance between the start of the Industrial Revolution and the mathematical demonstration of the role of carbon dioxide as a mediator of global temperature (the "greenhouse effect") is stated to be 120 years, whilst the distance between that demonstration and the present day is 128 years. Thus, we have now demonstrably lived longer with the knowledge of the potential problems than the we did with the era of possible ignorance of the matter. The appreciation of the matter, the belief in its truth and the ability to prove its reality may have taken more time to pass, but it marks the point after which humanity could no longer be said to be unaware of the potential implications.

Climate discussions may cite [https://onlinelibrary.wiley.com/doi/abs/10.1111/j.2153-3490.1957.tb01849.x a 1957 paper by Revell and Seuss] as "the starting point" for contemporary inquiries into global warming, but the comic points out that the matter was being debated, and the underlying mechanism correctly worked out, 61 years prior to Revell and Seuss. The implication, consistent with other [[:Category:Climate change|climate change]] themed xkcd comics, is that humans have taken insufficient action to slow or stop global warming despite knowing the mechanism for more than a century, and understanding, at least intellectually, the consequences of inaction.

The title text notes that the seemingly trivial prediction of CO2 levels in the far future have turned out to be very important, quoting Arrhenius as believing it wouldn't be valuable at all.<ref>Crawford, Elisabeth (1997). [https://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Greenhouse-effect/Arrhenius/3-optional-Crawford-1997.pdf "Arrhenius' 1896 Model of the Greenhouse Effect in Context"]. ''Ambio'' '''26'''(1):6-11. JSTOR [https://www.jstor.org/stable/4314543 4314543].</ref> Ironically, Arrhenius's calculations turned out to be both accurate and significant.

==Transcript==
:[At the top of the comic a timeline is shown as a long line. It has three dots, one at each end a bit inside the end of the line and one close to the middle Each dot has a gray curved line going up to it from below. Below the end of these lines a year is given. And beneath the year is a caption. Above the time line are two gray double arrows going from three gray lines above each of the three dots. The lines are broken in the middle where a label is written.]

:[Label of arrow that spans from first to second dot:]
:120 years

:[Label of arrow that spans from second to third dot:]
:128 years

:[Label for the first dot:]
:'''1776'''
:James Watt develops a steam engine that helps kick off the Industrial Revolution

:[Label for the second dot:]
:'''1896'''
:Arvid Högbom and Svante Arrhenius note that industrial activity is adding CO2 to the atmosphere, and calculate how much the Earth will heat up if the CO2 concentration doubles. Their answer closely matches modern estimates.

:[Label for the third dot:]
:'''2024'''
:Today

:[Caption below the panel:]
:We figured out the greenhouse effect closer to the start of the Industrial Revolution than to today.

==References==
<references/>

{{comic discussion}}

[[Category:Climate change]]
[[Category:Timelines]]
[[Category:Comics featuring real people]]