explain xkcd - User contributions [en]

1688: Map Age Guide

2016-06-01T14:09:55Z

Ijkcomputer: /* Explanation */

{{comic
| number = 1688
| date = June 1, 2016
| title = Map Age Guide
| image = map_age_guide.png
| titletext = Does the screeching chill your blood and herald death? If yes, banshee. If no, seagull.
}}

*A [http://xkcd.com/1688/large/ larger version] of this image can be found by clicking the image at xkcd.com - the comic's page can also be accessed by clicking on the comic number above.

==Explanation==
{{incomplete|Many is still missing.}}
Flowchart depicting various ways to tell what era a map is from based on present country borders and land forms. Most of the options are very serious,with a few bizarre options (mistaking a seagull and breadbox for a map) or references to things like the Discworld books and Middle-earth, the setting of the Lord Of the Rings series.

Additionally, (possible) future maps including a "Radioactive Exclusion Zone" in the place of Colorado are mentioned.

The title text continues this by inquiring of the (presumed) seagull might be a banshee based on the effect of its screams.

(First Draft, please expand.)

Going through the flowchart, taking the leftmost path first:

'''Istanbul or Constantinople''': The city that is now the capital of Turkey is famous for having different names at different times or to different people (and perhaps the inspiration for this comic.) Variations on both names go back at least 1,000 years. Other names have also been used at various points. Istanbul has been the official name since the 1920's, although Western maps often referred to it as Constantinople as late as the 1960's; on the flowchart, the choice of name appears to go with the 1920's date. The name changes are the subject of a [http://mentalfloss.com/article/60314/original-istanbul-not-constantinople song], originally by the Four Lads, but now mainly known for the They Might Be Giants recording.

==Transcript==
{{incomplete transcript}}

{{comic discussion}}

[[Category:Large drawings]]
[[Category:Maps]]
[[Category:Time]]
[[Category:Animals]]
[[Category:Geography]]

1606: Five-Day Forecast

2015-11-20T16:20:08Z

Ijkcomputer: /* Explanation */

{{comic
| number = 1606
| date = November 20, 2015
| title = Five-Day Forecast
| image = five_day_forecast.png
| titletext = You know what they say--if you don't like the weather here in the Solar System, just wait five billion years.
}}
==Explanation==
{{w|Weather forecasting}} is an extremely difficult task, even if it is only for five days. In numerical models, extremely small errors in initial values double roughly every five days for variables such as temperature and wind velocity. So most {{w| Meteorology#Meteorologists |meteorologists}} only provides us with a five day forecast.

In this comic [[Randall]] takes this to the extreme by first showing a [[Five-Day Forecast]] and then progressing to five-month, year, million, billion and finally trillion-year forecast.

Since the first weather symbol is the same in all six rows, we must assume this indicates the weather today (and not tomorrow on in a trillion years). It is first in the second panel that we have made the first jump according to the label.

When moving past the five days, the weather is just a qualified guess based on the time of year. In a month it is Christmas as shown in the second panel of the second row. And then it is winter with January and February so snow is likely, but certainly not something that happens on all days of a winter month.

Looking at the five-year forecast, guesses are made as to what the weather will be like at the same time of year. For these first three predictions the weather symbols are all of the same three types. Sun, clouds and some kind of {{w|precipitation}}, rain or snow. And the temperature range from 21 to 44°F (-6.1 to 6.6°C), winter temperature.

Then we go into the far future, jumping a million year from panel to panel. But still the weather symbols stay the same. However, in 3 million years time aliens (or advanced humans) attack with energy beams from something looking like {{w| flying saucers}}. They are gone a million years later. The temperature range is still the same (except that it rises to 52°F or 11.1°C, a possible reference to global warming) in one panel. But then while the attack is going on the temperature rises to 275°F (135°C).

Once we get to the billion-year mark it actually becomes more meaningful to try to predict the "weather". Because now we reach the times when the {{w|Sun}} begins to change. Although the Sun will continue to burn hydrogen for about 5 billion years yet (while in its {{w|Sun#Main_sequence| main sequence|}}), it will still grow in diameter as it begins to exhaust its supply of fuel. The core will contract to increase the temperature, and the outer layer will then compensate be expanding slightly. This is what is indicated in panel two and three where the color of the Sun changes towards red as the surface becomes less hot as it expands away from the center of the Sun. The temperature will rise on Earth as indicated in the panels (105°F = 40.5°C and 371°F = 188 °C). So in two billion years the temperature is hot enough that all the earth's oceans will have boiled away… Actually this will happen already in about [http://phys.org/news/2015-02-sun-wont-die-billion-years.html a billion years].

Then once there is {{w| Sun#After_core_hydrogen_exhaustion|no longer enough hydrogen}} the Sun will truly expand into a {{w|red giant}}. This should not happen until five billions years from now {{Citation needed}}, but in the forecast it is indicated to happen already in three. Maybe this is Randall taking liberties to show what happens during this phase, which would not fit into a five-billion-years forecast. Alternatively it is just indicating how uncertain these kind of forecasts are, or a statement that we may not know for certain that it will take five not three billion years.
Disregarding this, the fourth panel shows the temperature at Earth's position inside the red giant Sun. The color of the panel indicates that we are inside the Sun. The temperature is 71 million degrees Fahrenheit (almost 40 million degrees Celsius). The current temperature of the center of the Sun is "only" 27 million degrees Fahrenheit (15 million degrees Celsius). And although that may rise by a factor ten during {{w| Stellar nucleosynthesis |helium fusion}} then that will only be at the very core and not out in the solar atmosphere reaching out to Earth Here the temperature would only be of the order of thousands of Fahrenheit, since the Sun's outer temperature decreases as it increases its diameter. So this panels temperature also makes little sense. It may involve some ambiguities regarding what the forecast means; the edge of the red giant Sun is predicted to be somewhere near the current orbit of Earth, but the position of the Earth could change. The most likely prediction at the moment is for Earth to move outward, but if the planet is engulfed by the Sun, it would spiral inward (and at some point fall apart.) So in some sense "here" for the forecast could become a position deep inside the Sun, where core temperatures could reach 100 million Kelvin.

The red giant phase only last half a million years, so a billion years after the Sun has been a red giant its outer atmosphere will for sure have disappeared leaving only a {{w|white dwarf}} to cool down. Given Randall's version of this time schedule, then it will have had about a billion years to cool down, but would still likely be the brightest object in the sky as seen from where the Earth once was. It is not indicated in the last panel, where we just see other stars of the Galaxy. The temperature is down to that of the {{w|Cosmic microwave background |background radiation}}. Today this radiation has a temperature of 2.72548 Kelvin = -270.4245ºC = -454.7641ºF. So this is a few degree F colder than what is shown in the comic which states the temperature is -452ºF = 4.26 kelvin. This higher temperature may have been chosen to reflect that even the star light from other stars would increase the actual temperature.

In the last panel with trillion years, we jump right past the Sun's Red Giant phase, to a panel looking much like the one after five billions years with only other stars. Over the next three trillion years the stars become fewer and fewer and dimmer and dimmer as they run out of fuel and fewer new stars form. After four trillion years the background temperature even decreases one degree to -453ºF as the universe keeps expanding and the wave length of the radiation does the same (thus decreasing its temperature).

The title text is a play on comments referring to fast-changing weather on a more ordinary human timescale, such as Mark Twain's quip "If you don't like the weather in New England now, just wait a few minutes."

A ten days forecast was used in [[1245: 10-Day Forecast]]. In [[1379: 4.5 Degrees]] Randall looked at the weather over long periods of time as well.

==Transcript==
:[A grid with six rows of five columns, where each row is labeled to the left. For each of the 30 squares a temperature is given in Fahrenheit at the top left. The rest of the square represents the weather as in a weather forecast (or some other relevant items for the comic), mainly in bright colors. Below are the six labels given above each of their five weather symbols with temperature given below these symbols description.]

:'''Your 5-day forecast'''
:[A bright yellow sun.]
:38°F
:[A grey cloud.]
:41°F
:[A grey cloud with six lines of blue raindrops below.]
:36°F
:[A grey cloud in front of a yellow sun.]
:40°F
:[A bright yellow sun.]
:44°F

:'''Your 5-month forecast'''
:[A bright yellow sun.]
:38°F
:[A green Christmas tree with red presents beneath it.]
:29°F
:[A grey cloud with four snowflakes below.]
:21°F
:[A grey cloud with four snowflakes below.]
:24°F
:[A grey cloud.]
:35°F

:'''Your 5-year forecast'''
:[A bright yellow sun.]
:38°F
:[A grey cloud.]
:25°F
:[A bright yellow sun.]
:36°F
:[A grey cloud with six lines of blue raindrops below.]
:37°F
:[A bright yellow sun.]
:41°F

:'''Your 5-million-year forecast'''
:[A bright yellow sun.]
:38°F
:[A bright yellow sun.]
:52°F
:[A grey cloud.]
:40°F
:[Two red flying saucers (with bright domes) are shooting energy beams downwards. One of the beams seems to impact with something at the bottom of the panel, which then explodes. Two plumes of smoke rises up from below, drifting to the right.]
:275°F
:[A grey cloud in front of a yellow sun.]
:40°F

:'''Your 5-billion-year forecast'''
:[A bright yellow sun.]
:38°F
:[A larger orange sun.]
:105°F
:[A very large red sun.]
:371°F
:[A pale yellow panel with no drawing.]
:71.488.106°F
:[A night sky with many bright stars.]
:-452°F

:'''Your 5-trillion-year forecast'''
:[A bright yellow sun.]
:38°F
:[A night sky with many bright stars.]
:-452°F
:[A night sky with many stars.]
:-452°F
:[A night sky with fewer not so bright stars.]
:-452°F
:[A night sky with few dim stars.]
:-453°F

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Science]]
[[Category:Space]]
[[Category:Astronomy]]

1555: Exoplanet Names 2

2015-07-24T15:06:50Z

Ijkcomputer:

{{comic
| number = 1555
| date = July 24, 2015
| title = Exoplanet Names 2
| image = exoplanet_names_2.png
| titletext = I'm going to drive this Netherlands joke so far into the ground they'll have to build levees around it to keep the sea out.
}}

==Explanation==
{{incomplete|Complete table entries, check all table text (some black entries have changed), add wiki links, add explanations, red text to match comic?, detail on NASA announcement}}

This comic is a continuation of [[1253: Exoplanet Names]], and was published the day after NASA announced the discovery of a number of planets, including an Earth-like planet, Kepler-452b.
The {{w|International Astronomical Union}} (IAU) is the organisation which is responsible for naming celestial bodies (planets, stars, etc).

This table explains each entry in the comic table. The "New" column indicates if an entry is an addition since [[1253: Exoplanet Names]]. A "U" indicates the entry was updated.
{| class="wikitable"
! Star !! Planet !! New !! Suggested Name !! Explanation
|-
| rowspan=7 | {{w|Gliese 667}} || {{w|Gliese 667 Cb|b}} || N || Space Planet || A very unimaginative name; every planet is in space.
|-
|{{w|Gliese 667 Cc|c}} || N || PILF || Pun of {{w|MILF pornography|MILF}}, i.e. ''Planet I'd Like to Fuck''. Planet c is a relatively hot planet, within the habitable zone.
|-
|{{w|Gliese 667 Cd|d}} || N || A Star || "A {{w|Star}}" is obviously a bad name for a planet. A* (pronounced "A star") is already used in in astronomy, for example the Milky Way's black hole core is {{w|Sagittarius A*}}. "A star" is also the name for the character {{w|asterisk}} and the name of the popular {{w|A* search algorithm}} in computer science.
|-
|{{w|Gliese 667 Ce|e}} || N || e'); DROP TABLE PLANETS;-- || [[Mrs.Roberts]] is probably trying to use {{w|SQL injection}} like in [[327|Exploits of a Mom]], in which her son [[Robert'); DROP TABLE students;--]] caused the school a lot of trouble when his name was put in. The idea here is that the {{w|IAU}} would enter the name into their system and promptly lose all of their data pertaining to planets. Note that Planet e is located in the habitable zone of the star system.
|-
|{{w|Gliese 667 Cf|f}} || N || Blogosphere || rowspan = 2 | Weird ''{{w|blog}}''-related terms are a recurring theme in xkcd. See, for instance, [[181|comic 181]].
|-
|{{w|Gliese 667 Cg|g}} || N || Blogodrome
|-
|[http://exoplanet.eu/catalog/gj_667c_h/ h] || N || Earth || Planet candidate h is about the mass of the Earth, and described as "tantalizing": [http://www.aanda.org/articles/aa/abs/2013/08/aa21331-13/aa21331-13.html A dynamically-packed planetary system around GJ with three super-Earths in its habitable zone]. See also ([[1231: Habitable Zone]]). Like several other names below, naming a second planet Earth would be highly confusing.
|-
| rowspan=5 | {{w|Tau Ceti}} || [http://exoplanet.eu/catalog/tau_cet_b/ b] || N || Sid Meier's Tau Ceti B || This refers to the game {{w|Sid Meier's Alpha Centauri}}.
|-
| [http://exoplanet.eu/catalog/tau_cet_c/ c] || N || Giant Dog Planet || {{w|VY Canis Majoris}} is one of the largest known stars at our galaxy and belongs to the constellation {{w|Canis Major}}, Latin for "greater dog". The constellation further contains {{w|Sirius}}, the brightest star in the night sky, also called "Dog Star".
|-
|[http://exoplanet.eu/catalog/tau_cet_d/ d] || N || Tiny Dog Planet || cf. {{w|Canis Minor}}, Latin for "lesser dog", another constellation.
|-
|{{w|Tau Ceti e|e}} || N || Phil Plainet || A reference to {{w|Phil Plait}}, a.k.a. The Bad Astronomer.
|-
|{{w|Tau Ceti f|f}} || N || Unicode Snowman || The Unicode character [http://www.fileformat.info/info/unicode/char/2603/index.htm ☃] may be a reference to the planet's estimated surface temperature of -40 °C (-40 °F). However, this name would be pronounced differently (being a symbol, not a word or name) in different languages. Planets in our solar system are assigned to {{w|Astronomical symbols|astronomical symbols}} like ♁ for Earth or ♂ for Mars.
|-
| rowspan=2 | {{w|Gliese 832}} || {{w|Gliese 832 b|b}} || N || Asshole Jupiter || This massive planet orbits a {{w|red dwarf}} star at the longest known period of 3416 days at this category. Many exoplanets are described as "Hot Jupiters" because they are high-temperature gas giants; if one were to read "hot" as a description of attractiveness rather than temperature, one might generate names like this one.
|-
| {{w|Gliese 832 c|c}} || Y || Waterworld starring Kevin Kostner || Waterworld ([http://www.imdb.com/title/tt0114898/?ref_=fn_al_tt_1 imdb]) is a 1995 film starring Kevin Costner about Earth almost completely covered in water. It is unclear whether the surname being spelt incorrectly with a 'K' is intentional.
|-
| rowspan=6 | {{w|Gliese 581}} || {{w|Gliese 581 b|b}} || N || Waist-deep Cats || {{w|Waist Deep}} is an action film from 2006, and the {{w|Lolcat}} meme does not need explaining. The name may also simply be a reference to being "waist-deep" in (i.e. surrounded by many) cats.
|-
| {{w|Gliese|c}} || N || Planet #14 || About 200th discovered exoplanet (in 2007); reported to be the first potentially Earth-like planet in the habitable zone of its star, though that is in doubt now. The joke might be that like "Space Planet", "Planet #14" is a generic and unoriginal name. Also note that this is the 15th entry in the table so the numbering is {{w|Zero-based_numbering|zero-based}}.
An interesting (?) coincidence is that the 14th and 15th {{w|Definition of planet#Minor planets|Minor planets}} (then called asteroids) were discovered in 1851; see see {{w|List of minor planets: 1–1000}}. If they were to be counted among the planets of the {{w|Solar System}}, as was sometimes done then, the 14th known planetary body would be {{w| 7 Iris|Iris}} (discovered in 1847, a year before {{w|Neptune}}).
|-
|{{w|Gliese 581 d|d}} || N || Ballderaan || A {{w|wikt:balls|crude pun}} on the planet {{w|Alderaan}} from the ''{{w|Star Wars}}'' universe.
|-
|{{w|Gliese 581 e|e}} || N || Eternia Prime || {{w|Eternia}} is a fictional planet, venue of the ''{{w|Masters of the Universe}}'' animated series and toy collection.
|-
| {{w|Gliese 581 f|f}} || N || Taupe Mars || {{w|Kim Stanley Robinson}}'s award-winning {{w|Mars trilogy}} (''Red Mars, Green Mars, Blue Mars'' after various stages of {{w|terraformation}}). {{w|Taupe}} is a brownish-grey colour.
|-
|{{w|Gliese|g}} || N || Jelly-Filled Planet || Possibly a reference to the conjecture that this tidally locked planet has an isolated habitable zone under the substellar point, akin to the pocket of jelly in a jelly doughnut.
|-
| rowspan=2 | {{w|Epsilon Eridani}} || {{w|Epsilon Eridani b|b}} || N || Skydot || [http://skydot.lanl.gov SkyDOT] is the Sky Database for Objects in Time-Domain run by {{w|LANL}} for the {{w|U.S. Dept. of Energy}} and includes data for [http://skydot.lanl.gov/nsvs/star.php?num=14831575&mask=32004 Epsilon Eridani] that can be used to constrain the orbital parameters of ε Eri b. It may also refer to how objects in space may appear as bland, bright dots in the night sky.
|-
| {{w|Epsilon Eridani c#Planet_c|c}} || N || Laser Noises || A {{w|Laser}} does not produce {{w|Noise (electronics)|noise}} in the signal sense; it only works at a well defined frequency. In science fiction films, however, laser weapon discharges are usually accompanied by sound. Sun-like Epsilon Eridani became a popular setting for science fiction after its publicity as a target of the {{w|Project Ozma}} experiment.
|-
| rowspan=2 | {{w|Gliese 176}} || {{w|Gliese 176 b|b}} || N || Pandora || The mythological name {{w|Pandora}} fulfills most of IAU's guidelines and has been popular for planets in science fiction; most recently and famously is {{w|Pandora (Avatar)|the venue}} of James Cameron's ''{{w|Avatar (film)|Avatar}}'' (although actually it is not a planet but just a moon of a gas giant in Alfa Centauri A). It is also a hellish planet from {{w|Frank Herbert}}'s {{w|Frank Herbert bibliography#WorShip novels|WorShip}} series of novels, a jungle planet in Brothers Strugatsky's {{w|Noon Universe}} and the planet used in {{w|Borderlands (video game)|Borderlands Games}}.
|-
| [http://exoplanet.eu/catalog/gj_176_c/ c] || N || Pantera || Named for the {{w|Pantera|heavy metal band}} - which was named after an Italian sports car, the {{w|De Tomaso Pantera}}.
|-
| {{w|Kepler-61}} || {{w|Kepler-61b|b}} || N || GoldenPalace.com || A gambling website, known for {{w|GoldenPalace.com|paying to have their name in unusual places}} (like forehead tattoos, species names...).
|-
| {{w|Groombridge 34|Groombridge 34A}} || b || Y || Hot Mess || This is a reference to the phrase [http://arresteddevelopment.wikia.com/wiki/Hot_mess Hot mess] from the popular television show Arrested Development.
|-
| Kepler-442 || {{w|Kepler-442b|b}} || Y || Seas of Toothpaste ||
|-
| Gliese-442 || b || Y || This one weird planet || Most likely a reference to {{w|clickbait}} articles found on the internet.
|-
| rowspan=3 | EPIC-201367065 || b || Y || Sulwesi ||
|-
| c || Y || Huge Soccer Ball ||
|-
| d || Y || Geodude || [[http://bulbapedia.bulbagarden.net/wiki/Geodude_%28Pok%C3%A9mon%29 Geodude]] is a pokemon characterised by its ball-like shape. It resembles a clump of rocks.
|-
| rowspan=5 | Kepler-296 || b || Y || Kerbal Space Planet || {{w|Kerbal Space Program}} is a game where model rockets are launched on a scale version of the Earth. It has been referenced in xkcd a number of times ([[1106]], [[1244]], [[1356]]). Note, though, that the actual planet corresponding to the Earth in the game is called "Kerbin".
|-
| c || Y || A$aplanet || Most probably a pun on the rap group {{w|A$AP Mob}} and their most prominient member {{w|A$AP Rocky}}. May also be a pun on {{w|Kesha}}, also written as Ke$ha. In that case the c of the planet's designation would belong to the name.
|-
| d || Y || {{w|Jurassic World}} || Jurassic world is the most recent movie in the Jurassic park siries
|-
| {{w|Kepler-296e|e}} || Y || This Land || Reference to Wash's dialogue in the pilot episode of {{w|Firefly_(TV_Series)}}.
|-
| {{w|Kepler-296f|f}} || Y || Springfield || The name of {{w|Springfield (The Simpsons)|the town}} in which animated sitcom {{w|The Simpsons}} is set; possibly a reference to the running joke that the state in which Springfield is located has never been named.
|-
| rowspan=2 | {{w|HR 7722}} || {{w|HR 7722 b|b}} || Y || Betelgeuse || rowspan=2 | {{w|Betelgeuse}} is a star in the constellation Orion. It is commonly pronounced as "beetlejuice". {{w|Beetlejuice}}, however is a film directed by {{w|Tim Burton}} from 1988. Similarly to Dune/Arrakis and the two Uranuses, naming two planets with names that are generally regarded to be identical would cause severe confusion in astronomical discussions.
|-
| {{w|HR 7722 c|c}} || Y || Beetlejuice ||
|-
| EPIC201912552 || b || Y || Netherlands VI || As the title text a reference to [http://www.explainxkcd.com/wiki/index.php/what_if%3F What if?]'s [http://www.what-if.xkcd.com/53/ 53], [http://www.what-if.xkcd.com/54/ 54] and comic [[1551: Pluto]]. Due to a drain in the Earth's ocean the Netherlands have not to worry about getting flooded, anymore and take the opportunity to conquer the world (including Antarctica becoming South Netherlands) in What if 53, Mars (New Netherlands) in What if 54, and a section of Pluto (again: New Netherlands) in comic 1551. This may also be a possible reference to [[1519: Venus]], but there seems to be no relation to the other conquests of the Netherlands. Maybe it should also be mentioned, that {{w|New Netherland}} was a Dutch colony with {{w|New York City}}, formally known as {{w|New Amsterdam}}, as its capital. So the name "New Netherlands" can be assumed as "historically correct", while "Netherlands VI" isn't.
|-
| rowspan=3 | Gliese 3293 || b || Y || Antispit ||
|-
| c || Y || Google Earth || {{w|Google Earth}} is a service, similar to Google Maps, which projects satellite data on a 3D globe that can be zoomed in on. Other features, such as models of buildings, can also appear.
|-
| d || Y || Planet of the Apes (Disambiguation) || The way a Wikipedia article would be titled, for example, to distinguish from the {{w|Planet of the Apes (novel)|the original novel}}, {{w|Planet of the Apes (1968 film)|the first film}}, {{w|Planet of the Apes (2001 film)|the Tim Burton remake}} and {{w|Rise of the Planet of the Apes|the reboot series}}. In each adaptation, a group of astronauts lands on what is believed to be a "Planet of the Apes", which turns out to be a post-apocalyptic Earth.
|-
| rowspan=2 | Kepler-283 || b || Y || ˈjʊərənəs || rowspan = 2 | Two alternative pronunciations (written in {{w|International Phonetic Alphabet}}) for the planet name Uranus; the first one translates as "YU-ri-nus" (Urine-us), while the second translates as "you-RAIN-us", or, more commonly, "your anus".
|-
| c || Y || jʊ'reɪnəs
|-
! colspan=4 | (right column)
|-
| rowspan=4 | {{w|Upsilon Andromedae}} || b || Y || Fourthmeal || {{w|Taco_Bell}} has an ad campaign adding a meal after dinner. Possibly also a reference to {{w|Hobbit}}s and [http://askmiddlearth.tumblr.com/post/41765286488/the-seven-daily-hobbit-meals seven daily meals].
|-
|{{w|Upsilon Andromedae c|c}} || N || Stampy || The name of the elephant from the {{w|Simpsons}} episode {{w|Bart Gets an Elephant}}.
|-
|{{w|Upsilon Andromedae d|d}} || N || Moonchild || The name Bastian gives the Childlike Empress in {{w|The Neverending Story}}.
|-
|{{w|Upsilon Andromedae e|e}} || N || Ham Sphere || [http://www.hamsphere.com HamSphere] is a {{w|Amateur radio|Ham Radio}} simulator program. Ham radio uses designated radio frequencies for non-commercial exchange of messages and more. A pun of Hemisphere.
|-
| rowspan=3 | {{w|. Eridani|HD 20794}} || [http://exoplanet.eu/catalog/hd_20794_b/ b] || N || Cosmic Sands || style="font-family:'Comic Sans MS', 'Comic Sans'" | A {{w|pun}} on the name of the font {{w|Comic Sans}}. (See also: [[590|590: Papyrus]].)
|-
| [http://exoplanet.eu/catalog/hd_20794_c/ c] || N || Legoland || {{w|Legoland}} is a chain of {{w|theme park}}s owned by the {{w|Lego Group}}. Potentially a reference to the movie {{w|The World's End (film)|The World's End}}, in which the protagonist Gary King tells the alien invaders to "get in your rocket and fuck off back to Legoland".
|-
|[http://exoplanet.eu/catalog/hd_20794_d/ d] || N || Planet with Arms || A reference to the [http://www.thecolorsofmysoul.com/wp-content/uploads/2012/12/The-Hitchhikers-Guide-to-the-Galaxy.jpg early covers] of {{w|Hitchhiker's Guide to the Galaxy}}?
|-
| {{w|HD 85512}} || {{w|HD 85512 b|b}} || N || Lax Morality || Possibly a parody of science fiction in which certain planets are suggested to be uniformly... lax in morals (i.e. full of sex, drugs, etc.). See http://tvtropes.org/pmwiki/pmwiki.php/Main/Planetville and related.
|-
| rowspan=6 | {{w|HD 40307}} || {{w|HD 40307 b|b}} || N || Good Planet || Similar to the above, except with good planets. May also be yet another non-descriptive name, like "Space Planet" and "Planet #14".
|-
|{{w|HD|c}} || N || ProblemLand || See above.
|-
|{{w|HD 40307 d|d}} || N || Slickle || This is a reference to "[http://zdarsky.tumblr.com/post/2837139960 The Petals Fall Twice]", which was made as a humorous example of bad fan-fiction. The word itself is a portmanteau of "slowly", "licked", and "tickled".
|-
|{{w|HD 40307 e|e}} || N || Spare Parts || This suggests that the planet is "worthless" or "junk". This is false, of course. May be a reference to the fact it is a planet with nothing much different from the other planets.
|-
|{{w|HD 40307 f|f}} || N || New Jersey VI || Refers to the state of {{w|New Jersey}}; may be an insult to either.
|-
|{{w|HD|g}} || N || How Do I Join the IAU || This implies that the user "got lost" on the IAU website and thought that the "planet name suggestion" input was for general queries.
|-
| rowspan=3 | {{w|Gliese 163}} || [http://exoplanet.eu/catalog/gj_163_b/ b] || N || Neil Tyson's Mustache || {{w|Neil deGrasse Tyson}} is a famous American astrophysicist and science communicator who does maintain a distinguished mustache.
|-
|{{w|Gliese|c}} || N || help@gmail.com || Similar to "How Do I Join the IAU", this implies that the user confused the "planet suggestion" text box for a new email they are trying to send
|-
|[http://exoplanet.eu/catalog/gj_163_d/ d] || N || Hair-Covered Planet || Refers to the well-known {{w|Hairy ball theorem}} of topology.
|-
| {{w|Pi Mensae}} || {{w|Pi Mensae b|b}} || N || Moon Holder || {{w|Jupiter}} has more than 60 discovered moons, and still counting... A planet ten times more massive ''must'' also be a Moon Holder.
|-
| {{w|HD 189733}} || {{w|HD 189733 b|b}} || N || Permadeath || A well-characterized "{{w|Hot Jupiter}}" at a temperature range of 973 ± 33 K to 1,212 ± 11 K. The name refers to the feature of {{w|Permanent death}} common in many RPGs and roguelikes.
|-
| {{w|Kepler-22}} || {{w|Kepler-22 b|b}} || N || Blue Ivy || Blue Ivy Carter is the daughter of musicians {{w|Beyoncé}} and {{w|Jay-Z}}.
|-
| KOI-2474 || b || Y || Store-Brand Earth || A {w|Store brand} is a line of products branded by a retailer. They have a reputation for being lower quality than other brands, and are often marketed similarly to other brands. This is implying that this is a cheaper version of Earth.
|-
| Kepler-438 || b || U || Unicorn Thresher || As far as we can tell, Kepler-438b is in the vicinity of the constellation Monoceros, aka the Unicorn. (This was labeled Kepler-437b in the previous chart)
|-
| KOI-2418 || b || N || Spherical Discworld || {{w|The Discworld}} is the fictional setting for British author {{w|Terry Pratchett}}'s {{w|Discworld}} series of humorous fantasy novels; it consists of a large disc supported by four elephants themselves standing on top of a turtle flying through space.
|-
| Kepler-438 || b || Y || Emergency Backup Earth || This candidate planet has an {{w|Earth Similarity Index}} of 0.89, making it one of the most habitable {{w|Kepler object of interest}}. The name suggests that it could be used as a backup in case something happened to our current planet.
|-
| Kepler-3010 || b || N || Feeeoooooooop || Possibly the onomatopoeia for something getting sucked into a black hole.
|-
| Kepler-442 || b || N || Liz || ...Just a regular name (for a person, not a planet). Maybe a reference to the Magic School Bus.
|-
| rowspan=3 | 82 Eridani || b || Y || Horsemeat Surface||
|-
| c || Y || The Moon || This name would cause confusion with the Earth's moon, which in English is called The Moon. It is also a poor name choice as 82 Eridani c is not a moon, but a planet.
|-
| d || Y || Constant Saxophones ||
|-
| HD 102365 || b || Y || Little Big Planet || This refers to the videogame {{w|LittleBigPlanet|LittleBigPlanet}}.
|-
| rowspan=2 | Gliese 180 || b || Y || Dune || rowspan=2 | Both references to Frank Herbert's {{w|Dune_(novel)|Dune}} book series. The planet Arrakis (informally referred to as 'Dune') is the central planet in the mythology, where the mind-enhancing substance 'spice' comes from. Use of spice enables, among others, supercomputing-like mental computation as well as hyperspace navigation. Having two neighbouring planets with names that are historically used to refer to a single planet would sow further confusion in the already extensive catalog of planet names.
|-
| c || Y || Arrakis ||
|-
| Formalhaut || b || Y || Swarm of Bees ||
|-
| rowspan=5 | Kepler-62 || b || Y || Sporty || rowspan=5 | A reference to [[1554: Spice Girls]], where Megan was unable to list the members of the pop group. In this case the names are correct.
|-
| c || Y || Baby ||
|-
| d || Y || Scary ||
|-
| e || Y || Ginger ||
|-
| f || Y || Posh ||
|-
| rowspan=3 | HD 69830 || b || Y || Planet.xxx || {{w|.xxx}} is a controversial top level domain (like to .com and .net) that is intended to distinguish porn sites from other types of website.
|-
| c || Y || Novella || A {{w|novella}} is a form of prose with length between a {{w|short story}} and a {{w|novel}}. Common examples of novellas are romance literature centering around intense lustful encounters in cheap paperback books, though also 'serious' literature may be in novella form.
|-
| d || Y || Sexoplanet || Like the other two planets orbiting this star, the "69" in the stars designation has lead to a sex joke: All planets in this comic are "exo-planets", planets not orbiting our sun. Adding a single "s" in front results in immature humor.
|-
| rowspan=2 | {{w|Gliese 682}} || {{w|Gliese 682 b|b}} || Y || Verdant Hellscape || A contradictory name. "[[wikt:verdant|Verdant]]" usually signifies to be lush with green plantlife, while "[[wikt:hellscape|Hellscape]]" describes a desolate landscape destroyed by heat and cataclysm.
|-
| {{w|Gliese 682 c|c}} || Y || Unsubscribe || On YouTube, "subscribers" (people who get updates on a person's channel) are highly valued, and to "unsubscribe" from anyone is deemed to be offensive. "Unsubscribe" is also the command one sends to {{w|Electronic mailing list}}s to stop receiving said mailing list. In this sense it may imply a desire to no longer be bothered with these silly discussions around planet-names. Like "help@gmail.com" and "How do I join the IAU", "unsubscribe" is a frequently seen accidental message on the Internet in contexts where it is not going to work as a command.
|-
| {{w|Kepler-452}} || {{w|Kepler-452b|b}} || Y || Pluto || This is the planet Black Hat is referring to at the top of the table.
|}

==Transcript==
{{incomplete transcript}}

[Black Hat is pointing slide with image of Kepler-452b planet]
:Black Hat: NASA has announced the discovery of a (super-)Earth-sized planet in the habitable zone of a sun-like star.
:Black Hat: I suggest we name this planet "Pluto", both to celebrate the great work by the ''New Horizons'' team, and to make the stupid "Is Pluto a planet" debate a little more confusing

:[Table showing a list of planet names is shown.]

{| class="wikitable" |
While we wait to hear from the IAU, here's a revised and updated list of planet name suggestions (see xkcd.com/1253) New or updated entries in red
|-
|}

==Trivia==
The IPA character for stress is a vertical line ˈ. Randall uses a slanted line similar to acute accent ´ or prime ′.

{{comic discussion}}
[[Category:Firefly]]
[[Category:Astronomy]]
[[Category:Comics featuring Black Hat]]
[[Category:Exoplanets]]
[[Category:Comics with color]]

1555: Exoplanet Names 2

2015-07-24T15:02:37Z

Ijkcomputer:

{{comic
| number = 1555
| date = July 24, 2015
| title = Exoplanet Names 2
| image = exoplanet_names_2.png
| titletext = I'm going to drive this Netherlands joke so far into the ground they'll have to build levees around it to keep the sea out.
}}

==Explanation==
{{incomplete|Complete table entries, check all table text (some black entries have changed), add wiki links, add explanations, red text to match comic?, detail on NASA announcement}}

This comic is a continuation of [[1253: Exoplanet Names]], and was published the day after NASA announced the discovery of a number of planets, including an Earth-like planet, Kepler-452b.
The {{w|International Astronomical Union}} (IAU) is the organisation which is responsible for naming celestial bodies (planets, stars, etc).

This table explains each entry in the comic table. The "New" column indicates if an entry is an addition since [[1253: Exoplanet Names]]. A "U" indicates the entry was updated.
{| class="wikitable"
! Star !! Planet !! New !! Suggested Name !! Explanation
|-
| rowspan=7 | {{w|Gliese 667}} || {{w|Gliese 667 Cb|b}} || N || Space Planet || A very unimaginative name; every planet is in space.
|-
|{{w|Gliese 667 Cc|c}} || N || PILF || Pun of {{w|MILF pornography|MILF}}, i.e. ''Planet I'd Like to Fuck''. Planet c is a relatively hot planet, within the habitable zone.
|-
|{{w|Gliese 667 Cd|d}} || N || A Star || "A {{w|Star}}" is obviously a bad name for a planet. A* (pronounced "A star") is already used in in astronomy, for example the Milky Way's black hole core is {{w|Sagittarius A*}}. "A star" is also the name for the character {{w|asterisk}} and the name of the popular {{w|A* search algorithm}} in computer science.
|-
|{{w|Gliese 667 Ce|e}} || N || e'); DROP TABLE PLANETS;-- || [[Mrs.Roberts]] is probably trying to use {{w|SQL injection}} like in [[327|Exploits of a Mom]], in which her son [[Robert'); DROP TABLE students;--]] caused the school a lot of trouble when his name was put in. The idea here is that the {{w|IAU}} would enter the name into their system and promptly lose all of their data pertaining to planets. Note that Planet e is located in the habitable zone of the star system.
|-
|{{w|Gliese 667 Cf|f}} || N || Blogosphere || rowspan = 2 | Weird ''{{w|blog}}''-related terms are a recurring theme in xkcd. See, for instance, [[181|comic 181]].
|-
|{{w|Gliese 667 Cg|g}} || N || Blogodrome
|-
|[http://exoplanet.eu/catalog/gj_667c_h/ h] || N || Earth || Planet candidate h is about the mass of the Earth, and described as "tantalizing": [http://www.aanda.org/articles/aa/abs/2013/08/aa21331-13/aa21331-13.html A dynamically-packed planetary system around GJ with three super-Earths in its habitable zone]. See also ([[1231: Habitable Zone]]). Like several other names below, naming a second planet Earth would be highly confusing.
|-
| rowspan=5 | {{w|Tau Ceti}} || [http://exoplanet.eu/catalog/tau_cet_b/ b] || N || Sid Meier's Tau Ceti B || This refers to the game {{w|Sid Meier's Alpha Centauri}}.
|-
| [http://exoplanet.eu/catalog/tau_cet_c/ c] || N || Giant Dog Planet || {{w|VY Canis Majoris}} is one of the largest known stars at our galaxy and belongs to the constellation {{w|Canis Major}}, Latin for "greater dog". The constellation further contains {{w|Sirius}}, the brightest star in the night sky, also called "Dog Star".
|-
|[http://exoplanet.eu/catalog/tau_cet_d/ d] || N || Tiny Dog Planet || cf. {{w|Canis Minor}}, Latin for "lesser dog", another constellation.
|-
|{{w|Tau Ceti e|e}} || N || Phil Plainet || A reference to {{w|Phil Plait}}, a.k.a. The Bad Astronomer.
|-
|{{w|Tau Ceti f|f}} || N || Unicode Snowman || The Unicode character [http://www.fileformat.info/info/unicode/char/2603/index.htm ☃] may be a reference to the planet's estimated surface temperature of -40 °C (-40 °F). However, this name would be pronounced differently (being a symbol, not a word or name) in different languages. Planets in our solar system are assigned to {{w|Astronomical symbols|astronomical symbols}} like ♁ for Earth or ♂ for Mars.
|-
| rowspan=2 | {{w|Gliese 832}} || {{w|Gliese 832 b|b}} || N || Asshole Jupiter || This massive planet orbits a {{w|red dwarf}} star at the longest known period of 3416 days at this category. Many exoplanets are described as "Hot Jupiters" because they are high-temperature gas giants; if one were to read "hot" as a description of attractiveness rather than temperature, one might generate names like this one.
|-
| {{w|Gliese 832 c|c}} || Y || Waterworld starring Kevin Kostner || Waterworld ([http://www.imdb.com/title/tt0114898/?ref_=fn_al_tt_1 imdb]) is a 1995 film starring Kevin Costner about Earth almost completely covered in water. It is unclear whether the surname being spelt incorrectly with a 'K' is intentional.
|-
| rowspan=6 | {{w|Gliese 581}} || {{w|Gliese 581 b|b}} || N || Waist-deep Cats || {{w|Waist Deep}} is an action film from 2006, and the {{w|Lolcat}} meme does not need explaining. The name may also simply be a reference to being "waist-deep" in (i.e. surrounded by many) cats.
|-
| {{w|Gliese|c}} || N || Planet #14 || About 200th discovered exoplanet (in 2007); reported to be the first potentially Earth-like planet in the habitable zone of its star, though that is in doubt now. The joke might be that like "Space Planet", "Planet #14" is a generic and unoriginal name. Also note that this is the 15th entry in the table so the numbering is {{w|Zero-based_numbering|zero-based}}.
An interesting (?) coincidence is that the 14th and 15th {{w|Definition of planet#Minor planets|Minor planets}} (then called asteroids) were discovered in 1851; see see {{w|List of minor planets: 1–1000}}. If they were to be counted among the planets of the {{w|Solar System}}, as was sometimes done then, the 14th known planetary body would be {{w| 7 Iris|Iris}} (discovered in 1847, a year before {{w|Neptune}}).
|-
|{{w|Gliese 581 d|d}} || N || Ballderaan || A {{w|wikt:balls|crude pun}} on the planet {{w|Alderaan}} from the ''{{w|Star Wars}}'' universe.
|-
|{{w|Gliese 581 e|e}} || N || Eternia Prime || {{w|Eternia}} is a fictional planet, venue of the ''{{w|Masters of the Universe}}'' animated series and toy collection.
|-
| {{w|Gliese 581 f|f}} || N || Taupe Mars || {{w|Kim Stanley Robinson}}'s award-winning {{w|Mars trilogy}} (''Red Mars, Green Mars, Blue Mars'' after various stages of {{w|terraformation}}). {{w|Taupe}} is a brownish-grey colour.
|-
|{{w|Gliese|g}} || N || Jelly-Filled Planet || Possibly a reference to the conjecture that this tidally locked planet has an isolated habitable zone under the substellar point, akin to the pocket of jelly in a jelly doughnut.
|-
| rowspan=2 | {{w|Epsilon Eridani}} || {{w|Epsilon Eridani b|b}} || N || Skydot || [http://skydot.lanl.gov SkyDOT] is the Sky Database for Objects in Time-Domain run by {{w|LANL}} for the {{w|U.S. Dept. of Energy}} and includes data for [http://skydot.lanl.gov/nsvs/star.php?num=14831575&mask=32004 Epsilon Eridani] that can be used to constrain the orbital parameters of ε Eri b. It may also refer to how objects in space may appear as bland, bright dots in the night sky.
|-
| {{w|Epsilon Eridani c#Planet_c|c}} || N || Laser Noises || A {{w|Laser}} does not produce {{w|Noise (electronics)|noise}} in the signal sense; it only works at a well defined frequency. In science fiction films, however, laser weapon discharges are usually accompanied by sound. Sun-like Epsilon Eridani became a popular setting for science fiction after its publicity as a target of the {{w|Project Ozma}} experiment.
|-
| rowspan=2 | {{w|Gliese 176}} || {{w|Gliese 176 b|b}} || N || Pandora || The mythological name {{w|Pandora}} fulfills most of IAU's guidelines and has been popular for planets in science fiction; most recently and famously is {{w|Pandora (Avatar)|the venue}} of James Cameron's ''{{w|Avatar (film)|Avatar}}'' (although actually it is not a planet but just a moon of a gas giant in Alfa Centauri A). It is also a hellish planet from {{w|Frank Herbert}}'s {{w|Frank Herbert bibliography#WorShip novels|WorShip}} series of novels, a jungle planet in Brothers Strugatsky's {{w|Noon Universe}} and the planet used in {{w|Borderlands (video game)|Borderlands Games}}.
|-
| [http://exoplanet.eu/catalog/gj_176_c/ c] || N || Pantera || Named for the {{w|Pantera|heavy metal band}} - which was named after an Italian sports car, the {{w|De Tomaso Pantera}}.
|-
| {{w|Kepler-61}} || {{w|Kepler-61b|b}} || N || GoldenPalace.com || A gambling website, known for {{w|GoldenPalace.com|paying to have their name in unusual places}} (like forehead tattoos, species names...).
|-
| {{w|Groombridge 34|Groombridge 34A}} || b || Y || Hot Mess || This is a reference to the phrase [http://arresteddevelopment.wikia.com/wiki/Hot_mess Hot mess] from the popular television show Arrested Development.
|-
| Kepler-442 || {{w|Kepler-442b|b}} || Y || Seas of Toothpaste ||
|-
| Gliese-442 || b || Y || This one weird planet || Most likely a reference to {{w|clickbait}} articles found on the internet.
|-
| rowspan=3 | EPIC-201367065 || b || Y || Sulwesi ||
|-
| c || Y || Huge Soccer Ball ||
|-
| d || Y || Geodude || [[http://bulbapedia.bulbagarden.net/wiki/Geodude_%28Pok%C3%A9mon%29 Geodude]] is a pokemon characterised by its ball-like shape. It resembles a clump of rocks.
|-
| rowspan=5 | Kepler-296 || b || Y || Kerbal Space Planet || {{w|Kerbal Space Program}} is a game where model rockets are launched on a scale version of the Earth. It has been referenced in xkcd a number of times ([[1106]], [[1244]], [[1356]]). Note, though, that the actual planet corresponding to the Earth in the game is called "Kerbin".
|-
| c || Y || A$aplanet || Most probably a pun on the rap group {{w|A$AP Mob}} and their most prominient member {{w|A$AP Rocky}}. May also be a pun on {{w|Kesha}}, also written as Ke$ha. In that case the c of the planet's designation would belong to the name.
|-
| d || Y || {{w|Jurassic World}} || Jurassic world is the most recent movie in the Jurassic park siries
|-
| {{w|Kepler-296e|e}} || Y || This Land || Reference to Wash's dialogue in the pilot episode of {{w|Firefly_(TV_Series)}}.
|-
| {{w|Kepler-296f|f}} || Y || Springfield || The name of {{w|Springfield (The Simpsons)|the town}} in which animated sitcom {{w|The Simpsons}} is set; possibly a reference to the running joke that the state in which Springfield is located has never been named.
|-
| rowspan=2 | {{w|HR 7722}} || {{w|HR 7722 b|b}} || Y || Betelgeuse || rowspan=2 | {{w|Betelgeuse}} is a star in the constellation Orion. It is commonly pronounced as "beetlejuice". {{w|Beetlejuice}}, however is a film directed by {{w|Tim Burton}} from 1988. Similarly to Dune/Arrakis and the two Uranuses, naming two planets with names that are generally regarded to be identical would cause severe confusion in astronomical discussions.
|-
| {{w|HR 7722 c|c}} || Y || Beetlejuice ||
|-
| EPIC201912552 || b || Y || Netherlands VI || As the title text a reference to [http://www.explainxkcd.com/wiki/index.php/what_if%3F What if?]'s [http://www.what-if.xkcd.com/53/ 53], [http://www.what-if.xkcd.com/54/ 54] and comic [[1551: Pluto]]. Due to a drain in the Earth's ocean the Netherlands have not to worry about getting flooded, anymore and take the opportunity to conquer the world (including Antarctica becoming South Netherlands) in What if 53, Mars (New Netherlands) in What if 54, and a section of Pluto (again: New Netherlands) in comic 1551. This may also be a possible reference to [[1519: Venus]], but there seems to be no relation to the other conquests of the Netherlands. Maybe it should also be mentioned, that {{w|New Netherland}} was a Dutch colony with {{w|New York City}}, formally known as {{w|New Amsterdam}}, as its capital. So the name "New Netherlands" can be assumed as "historically correct", while "Netherlands VI" isn't.
|-
| rowspan=3 | Gliese 3293 || b || Y || Antispit ||
|-
| c || Y || Google Earth || {{w|Google Earth}} is a service, similar to Google Maps, which projects satellite data on a 3D globe that can be zoomed in on. Other features, such as models of buildings, can also appear.
|-
| d || Y || Planet of the Apes (Disambiguation) || The way a Wikipedia article would be titled, for example, to distinguish from the {{w|Planet of the Apes (novel)|the original novel}}, {{w|Planet of the Apes (1968 film)|the first film}}, {{w|Planet of the Apes (2001 film)|the Tim Burton remake}} and {{w|Rise of the Planet of the Apes|the reboot series}}. In each adaptation, a group of astronauts lands on what is believed to be a "Planet of the Apes", which turns out to be a post-apocalyptic Earth.
|-
| rowspan=2 | Kepler-283 || b || Y || ˈjʊərənəs || rowspan = 2 | Two alternative pronunciations (written in {{w|International Phonetic Alphabet}}) for the planet name Uranus; the first one translates as "YU-ri-nus" (Urine-us), while the second translates as "you-RAIN-us", or, more commonly, "your anus".
|-
| c || Y || jʊ'reɪnəs
|-
! colspan=4 | (right column)
|-
| rowspan=4 | {{w|Upsilon Andromedae}} || b || Y || Fourthmeal || {{w|Taco_Bell}} has an ad campaign adding a meal after dinner. Possibly also a reference to {{w|Hobbit}}s and [http://askmiddlearth.tumblr.com/post/41765286488/the-seven-daily-hobbit-meals seven daily meals].
|-
|{{w|Upsilon Andromedae c|c}} || N || Stampy || The name of the elephant from the {{w|Simpsons}} episode {{w|Bart Gets an Elephant}}.
|-
|{{w|Upsilon Andromedae d|d}} || N || Moonchild || The name Bastian gives the Childlike Empress in {{w|The Neverending Story}}.
|-
|{{w|Upsilon Andromedae e|e}} || N || Ham Sphere || [http://www.hamsphere.com HamSphere] is a {{w|Amateur radio|Ham Radio}} simulator program. Ham radio uses designated radio frequencies for non-commercial exchange of messages and more. A pun of Hemisphere.
|-
| rowspan=3 | {{w|. Eridani|HD 20794}} || [http://exoplanet.eu/catalog/hd_20794_b/ b] || N || Cosmic Sands || style="font-family:'Comic Sans MS', 'Comic Sans'" | A {{w|pun}} on the name of the font {{w|Comic Sans}}. (See also: [[590|590: Papyrus]].)
|-
| [http://exoplanet.eu/catalog/hd_20794_c/ c] || N || Legoland || {{w|Legoland}} is a chain of {{w|theme park}}s owned by the {{w|Lego Group}}. Potentially a reference to the movie {{w|The World's End (film)|The World's End}}, in which the protagonist Gary King tells the alien invaders to "get in your rocket and fuck off back to Legoland".
|-
|[http://exoplanet.eu/catalog/hd_20794_d/ d] || N || Planet with Arms || A reference to the [http://www.thecolorsofmysoul.com/wp-content/uploads/2012/12/The-Hitchhikers-Guide-to-the-Galaxy.jpg early covers] of {{w|Hitchhiker's Guide to the Galaxy}}?
|-
| {{w|HD 85512}} || {{w|HD 85512 b|b}} || N || Lax Morality || Possibly a parody of science fiction in which certain planets are suggested to be uniformly... lax in morals (i.e. full of sex, drugs, etc.). See http://tvtropes.org/pmwiki/pmwiki.php/Main/Planetville and related.
|-
| rowspan=6 | {{w|HD 40307}} || {{w|HD 40307 b|b}} || N || Good Planet || Similar to the above, except with good planets. May also be yet another non-descriptive name, like "Space Planet" and "Planet #14".
|-
|{{w|HD|c}} || N || ProblemLand || See above.
|-
|{{w|HD 40307 d|d}} || N || Slickle || This is a reference to "[http://zdarsky.tumblr.com/post/2837139960 The Petals Fall Twice]", which was made as a humorous example of bad fan-fiction. The word itself is a portmanteau of "slowly", "licked", and "tickled".
|-
|{{w|HD 40307 e|e}} || N || Spare Parts || This suggests that the planet is "worthless" or "junk". This is false, of course. May be a reference to the fact it is a planet with nothing much different from the other planets.
|-
|{{w|HD 40307 f|f}} || N || New Jersey VI || Refers to the state of {{w|New Jersey}}; may be an insult to either.
|-
|{{w|HD|g}} || N || How Do I Join the IAU || This implies that the user "got lost" on the IAU website and thought that the "planet name suggestion" input was for general queries.
|-
| rowspan=3 | {{w|Gliese 163}} || [http://exoplanet.eu/catalog/gj_163_b/ b] || N || Neil Tyson's Mustache || {{w|Neil deGrasse Tyson}} is a famous American astrophysicist and science communicator who does maintain a distinguished mustache.
|-
|{{w|Gliese|c}} || N || help@gmail.com || Similar to "How Do I Join the IAU", this implies that the user confused the "planet suggestion" text box for a new email they are trying to send
|-
|[http://exoplanet.eu/catalog/gj_163_d/ d] || N || Hair-Covered Planet || Refers to the well-known {{w|Hairy ball theorem}} of topology.
|-
| {{w|Pi Mensae}} || {{w|Pi Mensae b|b}} || N || Moon Holder || {{w|Jupiter}} has more than 60 discovered moons, and still counting... A planet ten times more massive ''must'' also be a Moon Holder.
|-
| {{w|HD 189733}} || {{w|HD 189733 b|b}} || N || Permadeath || A well-characterized "{{w|Hot Jupiter}}" at a temperature range of 973 ± 33 K to 1,212 ± 11 K. The name refers to the feature of {{w|Permanent death}} common in many RPGs and roguelikes.
|-
| {{w|Kepler-22}} || {{w|Kepler-22 b|b}} || N || Blue Ivy || Blue Ivy Carter is the daughter of musicians {{w|Beyoncé}} and {{w|Jay-Z}}.
|-
| KOI-2474 || b || Y || Store-Brand Earth || A {w|Store brand} is a line of products branded by a retailer. They have a reputation for being lower quality than other brands, and are often marketed similarly to other brands. This is implying that this is a cheaper version of Earth.
|-
| Kepler-438 || b || U || Unicorn Thresher || As far as we can tell, Kepler-438b is in the vicinity of the constellation Monoceros, aka the Unicorn. (This was labeled Kepler-437b in the previous chart)
|-
| KOI-2418 || b || N || Spherical Discworld || {{w|The Discworld}} is the fictional setting for British author {{w|Terry Pratchett}}'s {{w|Discworld}} series of humorous fantasy novels; it consists of a large disc supported by four elephants themselves standing on top of a turtle flying through space.
|-
| Kepler-438 || b || Y || Emergency Backup Earth || This candidate planet has an {{w|Earth Similarity Index}} of 0.89, making it one of the most habitable {{w|Kepler object of interest}}. The name suggests that it could be used as a backup in case something happened to our current planet.
|-
| Kepler-3010 || b || N || Feeeoooooooop || Possibly the onomatopoeia for something getting sucked into a black hole.
|-
| Kepler-442 || b || N || Liz || ...Just a regular name (for a person, not a planet). Maybe a reference to the Magic School Bus.
|-
| rowspan=3 | 82 Eridani || b || Y || Horsemeat Surface||
|-
| c || Y || The Moon || This name would cause confusion with the Earth's moon, which in English is called The Moon. It is also a poor name choice as 82 Eridani c is not a moon, but a planet.
|-
| d || Y || Constant Saxophones ||
|-
| HD 102365 || b || Y || Little Big Planet || This refers to the videogame {{w|LittleBigPlanet|LittleBigPlanet}}.
|-
| rowspan=2 | Gliese 180 || b || Y || Dune || rowspan=2 | Both references to Frank Herbert's {{w|Dune_(novel)|Dune}} book series. The planet Arrakis (informally referred to as 'Dune') is the central planet in the mythology, where the mind-enhancing substance 'spice' comes from. Use of spice enables, among others, supercomputing-like mental computation as well as hyperspace navigation. Having two neighbouring planets with names that are historically used to refer to a single planet would sow further confusion in the already extensive catalog of planet names.
|-
| c || Y || Arrakis ||
|-
| Formalhaut || b || Y || Swarm of Bees ||
|-
| rowspan=5 | Kepler-62 || b || Y || Sporty || rowspan=5 | A reference to [[1554: Spice Girls]], where Megan was unable to list the members of the pop group. In this case the names are correct.
|-
| c || Y || Baby ||
|-
| d || Y || Scary ||
|-
| e || Y || Ginger ||
|-
| f || Y || Posh ||
|-
| rowspan=3 | HD 69830 || b || Y || Planet.xxx || {{w|.xxx}} is a controversial top level domain (like to .com and .net) that is intended to distinguish porn sites from other types of website.
|-
| c || Y || Novella || A {{w|novella}} is a form of prose with length between a {{w|short story}} and a {{w|novel}}. Common examples of novellas are romance literature centering around intense lustful encounters in cheap paperback books, though also 'serious' literature may be in novella form.
|-
| d || Y || Sexoplanet || Like the other two planets orbiting this star, the "69" in the stars designation has lead to a sex joke: All planets in this comic are "exo-planets", planets not orbiting our sun. Adding a single "s" in front results in immature humor.
|-
| rowspan=2 | {{w|Gliese 682}} || {{w|Gliese 682 b|b}} || Y || Verdant Hellscape || A contradictory name. "[[wikt:verdant|Verdant]]" usually signifies to be lush with green plantlife, while "[[wikt:hellscape|Hellscape]]" describes a desolate landscape destroyed by heat and cataclysm.
|-
| {{w|Gliese 682 c|c}} || Y || Unsubscribe || On YouTube, "subscribers" (people who get updates on a person's channel) are highly valued, and to "unsubscribe" from anyone is deemed to be offensive. "Unsubscribe" is also the command one sends to {{w|Electronic mailing list}}s to stop receiving said mailing list. In this sense it may imply a desire to no longer be bothered with these silly discussions around planet-names.
|-
| {{w|Kepler-452}} || {{w|Kepler-452b|b}} || Y || Pluto || This is the planet Black Hat is referring to at the top of the table.
|}

==Transcript==
{{incomplete transcript}}

[Black Hat is pointing slide with image of Kepler-452b planet]
:Black Hat: NASA has announced the discovery of a (super-)Earth-sized planet in the habitable zone of a sun-like star.
:Black Hat: I suggest we name this planet "Pluto", both to celebrate the great work by the ''New Horizons'' team, and to make the stupid "Is Pluto a planet" debate a little more confusing

:[Table showing a list of planet names is shown.]

{| class="wikitable" |
While we wait to hear from the IAU, here's a revised and updated list of planet name suggestions (see xkcd.com/1253) New or updated entries in red
|-
|}

==Trivia==
The IPA character for stress is a vertical line ˈ. Randall uses a slanted line similar to acute accent ´ or prime ′.

{{comic discussion}}
[[Category:Firefly]]
[[Category:Astronomy]]
[[Category:Comics featuring Black Hat]]
[[Category:Exoplanets]]
[[Category:Comics with color]]

1547: Solar System Questions

2015-07-08T14:18:37Z

Ijkcomputer: /* Explanation */

{{comic
| number = 1547
| date = July 6, 2015
| title = Solar System Questions
| image = solar_system_questions.png
| titletext = My country's World Cup win was exciting and all, but c'mon, what if the players wore nylon wings and COULD LITERALLY FLY?
}}

==Explanation==
This comic is a list of questions which [[Randall]] has about the Solar System, which at first glance may appear to be things that Randall would like to learn about.
In actuality, most of the questions have not been satisfactorily answered or proven by anyone in the {{w|List_of_unsolved_problems_in_physics#Astronomy_and_astrophysics|scientific community}}.

{| class="wikitable"
|-
! Question given
! Answer given by Randall (in red in the original)
! Comments
|-
| Why is the the Moon so blotchy?
| Lava
| The {{w|Moon}} is in synchronous rotation with Earth, which means that we always can see only one half of the surface of the Moon. And on that side we can see large {{w|lunar maria}} formed by lava from big volcanoes. This surface is very different to all other celestial bodies we know in our Solar system. The double "the the" could be a Randallism — intended or unintended.
|-
| Why are all the blotches on the near side?
| ...
| The nearside of the Moon is dominated by the blotchy 'seas' or maria, the far side by craters. {{w|Far_side_of_the_Moon#Differences|Several explanations}} for this have been proposed, including an overabundance of impacts obliterating the blotches on the more exposed far side, different compositions of heat-producing elements, large collisions, or heat produced by the still-cooling Earth.
|-
| Did Mars have seas?
| Yes (briefly?)
| Recent explorations have confirmed there was once standing (and also flowing) water on {{w|Mars}}. Many rovers and orbiters on Mars give us the evidence on this early development of that planet, but it is still unknown how long such conditions existed in its history. Two of these probes have been the subject of comics before: [[695: Spirit]] and [[1504: Opportunity]].
|-
| Was there life on Mars?
| ...
| One of the big mysteries, {{w|Life on Mars|not yet answered}}.
|-
| What's Titan like?
| Cold, yellow, lakes + rivers (methane)
| The {{w|Cassini–Huygens}} mission confirmed the presence of {{w|Lakes_of_Titan|lakes and rivers}} on {{w|Titan (moon)|Titan}}. The {{w|Huygens_(spacecraft)#Findings|Huygens}} lander itself returned some very yellow images of a dry lake bed from Titan's surface. The possibility of life on Titan was mentioned in [[829: Arsenic-Based Life]].
|-
| What was Earth like during the Hadean?
| ...
| The {{w|Hadean}} was the first geologic era on earth, the planet had just formed and not much is known of that period of Earth. But since it was the time when Earth was formed it was mainly very hot with extreme volcanic activity, with the entire surface melted. This is why the era is named after {{w|Hades}} the ancient Greek god of the underworld, even though Hades was never associated with fire.
|-
| Is the Oort Cloud a real thing?
| ...
| The {{w|Oort Cloud}} is a theoretical spherical cloud of icy planetesimal, maybe dust, and also larger objects at a distance of up to around 100,000 {{w|Astronomical units|AU}} to our Sun. We can see similar clouds at other stars, but there is still no evidence that this cloud exists in our Solar System.
|-
| Why is the Sun's corona so hot?
| Something about magnets?
| The {{w|corona}} of the sun is hotter than it theoretically should be. The looping magnetic fields in this area could be responsible.
|-
| What are comets like?
| Precipitous
| The {{w|Philae (spacecraft)|Philae lander}} is next to a cliff...
|-
| Where's Philae, exactly?
| ...
| ...but we're not sure ''which'' cliff. The landing of Philae was depicted in real time in the dynamic comic [[1446: Landing]]. This lasted for several hours. Later the comic was updated with a new image where Philae is resting on the edge of a cliff.
|-
| What's Pluto like?
| rowspan="2" | [Soon!]
| rowspan="2" | The probe {{w|New Horizons}} may be about to answer both of these questions, as it will reach its closest approach to both {{w|Pluto}} and {{w|Charon (moon)|Charon}} just eight days after the release of this comic. The probe was the subject of the comic [[1532: New Horizons]].
|-
| What's Charon like?
|-
| Why don't we have in-between-sized planets?
| ...
| There is a size-gap between the rocky {{w|terrestrial planets}} up to Earth size and the {{w|gas giants}} very much larger than Earth in our Solar System.
There are many known {{w|exoplanets}} (planets in other solar systems) filling in the range between our rocky planets and our gas giants, known as [https://upload.wikimedia.org/wikipedia/commons/2/2c/Exoplanet_Mass-Radius_Scatter_Super-Earth.png Super-Earths]
|-
| What's Ceres like?
| [Working on it!]
| The {{w|Dawn (spacecraft)|Dawn probe}} is currently exploring the {{w|dwarf planet}} {{w|Ceres (dwarf planet)|Ceres}} and reveals unseen surface features.
|-
| Why is Europa so weird-looking and pretty?
| Ice over a water ocean
| {{w|Europa (moon)|Europa}} is a moon of {{w|Jupiter}} and the surface is basically thick pack ice covered in {{w|lineae}}.
|-
| Why is Io so weird-looking?
| Sulfur volcanoes (? in the wrong places?)
| The moon {{w|Io (moon)|Io}} is also orbiting Jupiter and is close enough that {{w|tidal forces}} make it the most volcanic object in the solar system. The moon is mainly yellow but there a several other colors on the surface, for instance spots and streaks of bright red color that comes from {{w|sulfur}} which is ejected by the volcanoes. The "wrong places" refer to some volcanoes discovered by the {{w|Voyager program|Voyager missions}} and believed to erupt sulfur. But more recent measurements did show up that the temperature inside that volcanoes is about 2.000 °C where this element is not liquid any more but gas.
|-
| Why are so many Kuiper Belt objects red?
| ...
| Many objects in the {{w|Kuiper Belt}} have a reddish hue. A possible explanation is that they are [http://www.space.com/9418-icy-red-objects-solar-system-edge-point-life-building-blocks.html| covered in organic molecules] formed by the irradiation of their surface ices. The New Horizons probe might also shed light on this.
|-
| What are those spots on Ceres?
| ...
| The Dawn probe found some mysterious spots on the Ceres. These [http://photojournal.jpl.nasa.gov/jpeg/PIA19568.jpg white spots] are still not understood, but the mission is still running and we may figure out the source of the glowing white features. These spots became the punch line of the joke in [[1476: Ceres]].
|-
| What's in the seas under Europa's ice?
| ...
| The European {{w|ESA}} selected the mission {{w|Jupiter Icy Moon Explorer|Jupiter Icy Moon Explorer (JUICE)}} to Jupiter. The moon Europa is one target for that mission. But we have to wait, its launch target is 2022 and the arrival at Jupiter is planned for 2030. But that's not uncommon for missions like this, New Horizons or {{w|Rosetta (spacecraft)|Rosetta}} did also travel approx. ten years to reach their target. And before such a mission can start many preparations have to be done. {{w|2010: Odyssey Two}} is a 1982 science fiction novel by {{w|Arthur C. Clarke}} in which he envisions life under the ice on Europa. This life becomes a major plot point both in this and in the two sequels.
|-
| Which of the other moons have seas?
| Several
| Randall has already mentioned above that there are liquids on two moons. The Moon Titan at Saturn has lakes on its surface formed by liquid ethane, methane, and propane and the moon Europa of Jupiter has a sea of water cowered on a thick sheet of ice. Depending on the definition of 'sea', other less obviously 'frozen water world' moons such as {{w|Ganymede (moon)|Ganymede}} at Jupiter may have {{w|Ganymede (moon)#Subsurface oceans|subsurface}} [http://www.newscientist.com/article/dn27151-aurora-reveals-jupiter-moons-secret-subsurface-sea.html oceans] of liquid water and on other moons it could be other substance that are liquid at the relevant temperature, like on Titan.
|-
| What are the big white things in Titan's lakes?
| ...
| This is a joke about some gaps in the radar measurements as shown in this [https://commons.wikimedia.org/wiki/File:PIA10008_Seas_and_Lakes_on_Titan_full_size.jpg image].
|-
| What do Jupiter's clouds look like up close?
| ...
| The Jupiter mission {{w|Galileo (spacecraft)|Galileo}}, operated by NASA and the German Aerospace Center (DLR), arrived at Jupiter by 1995 and was sent to an impact on the planet at the end of that mission in 2003 to eliminate the possibility of contaminating local moons with terrestrial bacteria. Several measurements where done on the atmosphere but no pictures were sent back to Earth. So there is still no answer on this question.
|-
| What's all that red stuff in the Great Red Spot?
| ...
| The {{w|Great Red Spot}} is a storm, south of Jupiter's equator. Observations from Earth show a lifetime of more than 150 years. It's unknown why it's stable for that long time and it's also not clear why the color is red. The probe {{w|Juno (spacecraft)|Juno}} will arrive in July 2016 at Jupiter and maybe answer Randall's question.
|-
| What's pushing the Pioneer probes?
| Heat from the RTG
| Discussed as the {{w|Pioneer anomaly}}. RTG stands for {{w|Radioisotope Thermoelectric Generator}}. This effect was mentioned (and explained a little differently) in the title text of [[502: Dark Flow]].
|-
| What pushes spacecraft slightly during flybys?
| ...
| Several spacecraft experienced unexplained speed increases during Earth flybys. This is called the {{w|flyby anomaly}}.
|-
| Where are all the Sun's neutrinos?
| Oscillating
| See: {{w|Solar neutrino problem}}. Neutrino oscillation has been an observed phenomenon since the late 1990's; see {{w|Neutrino oscillation}}.
|-
| Why is there so much air on Titan?
| ...
| {{w|Titan (moon)|Titan}} has an atmospheric pressure 1.45 times that of Earth, but only 1/7th of the surface gravity which is less than Earth's own airless Moon has. Hence the confusion! In fact, Titan actually has almost 20% more atmosphere by mass than Earth, and ''seven times'' more atmosphere across a given surface area! Less influence from the more distant Sun probably helps retain more of the atmosphere's gasses (for instance, Mars saw most of its atmosphere blasted away by the sun), and {{w|cryovolcanoes}} may replenish the methane fraction which should by now have ''all'' been converted into the other hydrocarbons present from subsurface reservoirs. Further studies are required to properly answer this question.
|-
| Why does the Kuiper Belt stop?
| ...
| A reference to the {{w|Kuiper Cliff}}. The most far accumulation of known objects is roughly closer than 50 {{w|astronomical units|AU}}, after that distance only very few objects had been found. The reason for this is still unknown.
|-
| Why is Iapetus weird-colored?
| ...
| {{w|Iapetus (moon)|Iapetus}} is a moon of {{w|Saturn}} and always keeping the same face towards Saturn. The trailing side is white while the other side is dark.
|-
| Why does Iapetus have a belt?
| ...
| Iapetus has a 13 km high ridge around most of the equator, and a number of 10 km high mountains where the ridge is interrupted.
|-
| What's the deal with Miranda?
| ...
| {{w|Miranda_(moon)|Miranda}} is the smallest of {{w|Uranus}}' five round satellites, and it's {{w|Verona Rupes|a bit rough around the edges}} and also has an unusually high orbital inclination that is difficult to explain. Also possibly a [[Firefly|''Firefly'' reference]] since {{w|List of Firefly planets and moons#Miranda|Miranda}} is also the name of a planet in {{w|Serenity (film)|''Serenity''}}, a film basedion the {{w|Firefly (TV series)|''Firefly''}} TV series.
|-
| Did Uranus and Neptune change places?
| ...
| The {{w|Nice model}} is a theory of how our solar system formed, which suggested the possibility of Uranus and {{w|Neptune}} having swapped places before reaching their current positions. Work by Professor S. Desch [http://dusty.la.asu.edu/~desch/publications/2007/Desch2007.pdf also came to this result].
|-
| Did the Late Heavy Bombardment happen?
| ...
| The {{w|Late Heavy Bombardment}} did happen in the early history of Earth and the other rocky planets around the Sun. It's believed that by that time many big objects still existed and impacted to that planets. On Earth all those impacts are eroded but on Moon or Mercury without any atmosphere some evidences should be available. But this is still a matter for future science.
|-
| Did life start before it?
| ...
| For some speculation on this topic, see [http://www.livescience.com/5426-life-survived-earth-early-bombardment.html Life Could Have Survived Earth's Early Bombardment]. It is still a mystery if life was formed on Earth first or if it came from outer space.
|-
| Is Europa covered in ice spikes?
| ...
|Dr Daniel Hobley has put forward a [http://www.bbc.co.uk/news/science-environment-21341176 theory] that Jupiter's icy moon, {{w|Europa (moon)|Europa}}, has the right conditions to form ice spikes called {{w|penitentes}} of up to 10m in height.
|-
| Why haven't we built a big inflatable Extreme Sports Complex on The Moon?
| ...
| Apart from the question on the white on Titan, this is the only really silly question that has nothing to do with science or the solar system. However, it would be fun to watch sport in such a stadium - see the title text. See also, e.g., ''{{w|The Menace From Earth}}'', a 1957 short story by Robert Heinlein.
|}

The title text refers to the {{w|2015 FIFA Women's World Cup}} which was won by USA a day before. The nylon wings and flying may be a reference to two passages from 3001: The Final Odyssey, one where Frank Poole tries out various wings while in an extremely low gravity environment, and one where he remarks while watching Swan Lake that Tchaikovsky could never have imagined a performance where the dancers were actually flying (due to aforementioned low gravity). This is also a reference to the last point on the list, because if we had such a stadium on the moon, maybe it would be possible to use such wings to make very long floating leaps.

==Transcript==
:'''Questions I have'''
:'''about the solar system'''
:(some answered)

:{| class="wikitable" style="border: 0px;"
|-
| style="border: 0px; text-align: right" | Why is the the Moon so blotchy?
| style="border: 0px; color:red;" | Lava
|-
| style="border: 0px; text-align: right" | Why are all the blotches on the near side?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Did Mars have seas?
| style="border: 0px; color:red;" | Yes (briefly?)
|-
| style="border: 0px; text-align: right" | Was there life on Mars?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's Titan like?
| style="border: 0px; color:red;" | Cold, yellow, lakes + rivers (methane)
|-
| style="border: 0px; text-align: right" | What was Earth like during the Hadean?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Is the Oort Cloud a real thing?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Why is the Sun's corona so hot?
| style="border: 0px; color:red;" | Something about magnets?
|-
| style="border: 0px; text-align: right" | What are comets like?
| style="border: 0px; color:red;" | Precipitous
|-
| style="border: 0px; text-align: right" | Where's Philae, exactly?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's Pluto like?
| style="border: 0px; color:red;" rowspan="2" | [Soon!]
|-
| style="border: 0px; text-align: right" | What's Charon like?
|-
| style="border: 0px; text-align: right" | Why don't we have in-between-sized planets?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's Ceres like?
| style="border: 0px; color:red;" | [Working on it!]
|-
| style="border: 0px; text-align: right" | Why is Europa so wierd-looking and pretty?
| style="border: 0px; color:red;" | Ice over a water ocean
|-
| style="border: 0px; text-align: right" | Why is Io so weird-looking?
| style="border: 0px; color:red;" | Sulfur volcanoes (? in the wrong places?)
|-
| style="border: 0px; text-align: right" | Why are so many Kuiper Belt objects red?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What are those spots on Ceres?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's in the seas under Europa's ice?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Which of the other moons have seas?
| style="border: 0px; color:red;" | Several
|-
| style="border: 0px; text-align: right" | What are the big white things in Titan's Lakes?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What do Jupiter's clouds look like up close?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's all that red stuff in the Great Red Spot?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's pushing the Pioneer Probes?
| style="border: 0px; color:red;" | Heat from the RTG
|-
| style="border: 0px; text-align: right" | What pushes spacecraft slightly during flybys?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Where are all the Sun's Neutrinos?
| style="border: 0px; color:red;" | Oscillating
|-
| style="border: 0px; text-align: right" | Why is there so much air on Titan?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Why does the Kuiper Belt Stop?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Why is Iapetus weird-colored?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Why does Iapetus have a belt?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | What's the deal with Miranda?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Did Uranus and Neptune change places?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Did the Late Heavy Bombardment happen?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Did life start before it?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Is Europa covered in ice spikes?
| style="border: 0px;" |
|-
| style="border: 0px; text-align: right" | Why haven't we built a big inflatable extreme sports complex on the moon?
| style="border: 0px;" |
|}

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Charts]]
[[Category:Soccer]]
[[Category:Space]]
[[Category:Astronomy]]

Talk:1506: xkcloud

2015-04-01T19:56:55Z

Ijkcomputer:

The lack of a hover text breaks all sorts of things :) e.g. Floern's unofficial xkcd browser linked here via the hover text but it won't display the link or the lack of give text if there's no hover text! We may get a few less visitors for this comic as a result...

[[Special:Contributions/108.162.229.115|108.162.229.115]] 08:42, 1 April 2015 (UTC)
:Still getting swamped, it's business as usual for April 1st. '''[[User:Davidy22|{{Color|#707|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 09:06, 1 April 2015 (UTC)

Why is "literally on fire" a question? [[Special:Contributions/108.162.249.163|108.162.249.163]] 09:52, 1 April 2015 (UTC)

:It indicates uncertainty. He's not really asking a question, but making a statement hesitantly. {{unsigned ip|141.101.99.22}}

::Indeed, see also {{w|uptalk}}. [[User:Pesthouse|Pesthouse]] ([[User talk:Pesthouse|talk]]) 10:03, 1 April 2015 (UTC)

How does i work? Does it work? When i click the "Help us"-Button i just get a blank comic with "..." written at the top :( [[Special:Contributions/108.162.254.148|108.162.254.148]] 10:14, 1 April 2015 (UTC)

Oh boy, time to find out if mediawiki does imagemaps.--[[User:Henke37|Henke37]] ([[User talk:Henke37|talk]]) 10:31, 1 April 2015 (UTC)

The image was updated on xkcd.com the button now reads "Click here to help us recover user data before facebook & ca notice we lost it [[User:ẞ qwertz|ẞ qwertz]] ([[User talk:ẞ qwertz|talk]]) 10:48, 1 April 2015 (UTC)
:Can someone update the picture without just making a screen shoot? It is not like you can save it the normal way. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 14:39, 1 April 2015 (UTC)
::I have never understood how this works. I did try to change to the new version, but it somehow keeps loading the old version, even though I know that I did load a new version up. Even on the file page my file loads as the wrong one. I have tried this more than once... Previously the image has updates to the new version later without a new upload appearing. But I have no idea why...? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:39, 1 April 2015 (UTC)

I decided to '''man up''', get the train rolling and submitted the '''first revision''' of the explanation. Do expand, retouch, overwrite, format and correct my simple explanation. I didn't know if the 3 already existing posts, the ambiguous text posts or the drawings are user-based, so I avoided saying so in the explanation. I'll just add something about the covet/thirst/hanker/crave in a moment, and I'm done. [[Special:Contributions/173.245.53.151|173.245.53.151]] 11:11, 1 April 2015 (UTC)

This comic has an empty alt text. See http://m.xkcd.com/1506/. [[Special:Contributions/108.162.221.201|108.162.221.201]] 13:50, 1 April 2015 (UTC)

* There's a silent character limit (no error message, just non-acceptance; You can still comment the image again, but the text is lost unless you copied it first) somewhere between 222 and 298 chars. I tried to make a start at playing Identik with an image, but only came half way through. Guess, I have to write shorter...
* Someone figured out, how to copy&paste some grayscale image.
* I managed to submit a color image, but haven't seen it coming back yet. Tell me when you find a red one.
* There is at least one image that is too fine to have been drawn in that minimal editor (squirrel+football). I guess, it's one of the initial images that Randall provided. -- [[User:Xorg|Xorg]] ([[User talk:Xorg|talk]]) 14:00, 1 April 2015 (UTC)
** There's also an image of Buzz Lightyear that appears to be copy-pasted in. I'm not sure how someone would have accomplished that. How did you mange to get color, user 2 above me? If anyone seems a stick-figure comic titled 2006 in which one character says to the other "You're never going to achieve anything if you spend all your time on that web comic ... Now back to my Zune research", that's mine. Post here and let me know! [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 14:33, 1 April 2015 (UTC)
*** I used the web console to get a drawing context on the canvas object. After submission the image was actually transferred to the lower area, but now, I suspect that it wasn't really the data that got uploaded... -- [[User:Xorg|Xorg]] ([[User talk:Xorg|talk]]) 15:00, 1 April 2015 (UTC)
:Yes although I'm certain that most of the images are from users, it would be nice to hear from someone who can confirm that one of their images has been spotted {{unsigned|Kynde}}
::I can at least confirm that one of my texts has been spottet by someone else. I got the black image and wrote "I finally managed to disable the flashlight of my camera". Later I saw an image combining a hammer, a nail and a camera to depict my description. -- [[User:Xorg|Xorg]] ([[User talk:Xorg|talk]]) 15:00, 1 April 2015 (UTC)
::The last computer device at the far right is a first generation SNES. [[Special:Contributions/173.245.56.193|173.245.56.193]] 15:12, 1 April 2015 (UTC)X
:::I keep reading the unidentified computer (second to rightmost) as a SunSPARC (that could kinda be the Sun logo) or a NEXT cube (right shape but no match to the logo) or something. Not sure where someone got 'radio transmitter'. [[User:Ijkcomputer|Ijkcomputer]] ([[User talk:Ijkcomputer|talk]]) 19:56, 1 April 2015 (UTC)
*I think the general idea is based on a game that I think is called the fax machine game? [[Special:Contributions/198.41.242.5|198.41.242.5]] 15:29, 1 April 2015 (UTC)

I really, really, hope that some people have seen my contributions. They're pretty damn funny. [[User:YourLifeisaLie|The Goyim speaks]] ([[User talk:YourLifeisaLie|talk]]) 17:20, 1 April 2015 (UTC)

Talk:1484: Apollo Speeches

2015-02-10T15:33:06Z

Ijkcomputer:

[http://watergate.info/1969/07/20/an-undelivered-nixon-speech.html Speech] for reference[[User:Blawho|Blawho]] ([[User talk:Blawho|talk]]) 06:40, 9 February 2015 (UTC)

Any chance the scenario with extra astronauts coming back is a reference to Scott Card's Xenocide, in the book they find a way for FTL travel but some odd things happen on the first voyage including extra people coming back ([http://en.wikipedia.org/wiki/Xenocide#Outside click if you're not afraid of spoilers])? {{unsigned ip|188.114.98.29}}

Probably it could also be a reference to Tarkowski's movie "Solaris"? {{unsigned ip|141.101.92.93}}

:: It's also similar to the premise of the comic ''[https://en.wikipedia.org/wiki/The_Chimpanzee_Complex The Chimpanzee Complex]''. Probably just a coincidence, though. – [[User:PhantomLimbic|PhantomLimbic]] ([[User talk:PhantomLimbic|talk]]) 17:06, 9 February 2015 (UTC)

Anyone remember the Saturday Night Live skit with Dana Carvey as Tom Brokaw recording contingency broadcasts reporting on Gerald Ford's death from more and more unlikely circumstances (including one where Brokaw was told to add, "and also, I'm gay", because "If that happens, you don't want another reporter to get the scoop!") [[User:Mwburden|mwburden]] ([[User talk:Mwburden|talk]]) 17:55, 9 February 2015 (UTC)

"there is some corner of another world that is forever mankind" has to be a reference to the Rupert Brooke poem ''The Soldier'', which Safire no doubt knew. It begins "If I should die, think only this of me:/That there's some corner of a foreign field/That is forever England." {{unsigned ip|108.162.246.219}}
:Maybe, but that would not be a reference in the context of the comic, since the first two pages are from the actual speech. -Pennpenn [[Special:Contributions/108.162.250.155|108.162.250.155]] 23:19, 9 February 2015 (UTC)

You know, technically Apollo 11 probably had enough delta-v to make it into Mars orbit - the service module alone had around 2.8 km/s - although I don't know if there was a point in the actual mission where you could have made this work. Nobody would have survived the trip, of course. [[User:Ijkcomputer|Ijkcomputer]] ([[User talk:Ijkcomputer|talk]]) 15:33, 10 February 2015 (UTC)

Talk:936: Password Strength

2014-12-18T15:32:49Z

Ijkcomputer:

You still have to vary the words with a bit of capitalization, punctuation and numbers a bit, or hackers can just run a dictionary attack against your string of four words. '''[[User:Davidy22|{{Color|purple|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 09:12, 9 March 2013 (UTC)

No you don't. Hackers cannot run a dictionary attack against a string of four randomly picked words.
Look at the number of bits displayed in the image: 11 bits for each word.
That means he's assuming a dictionary of 2048 words, from which each word is picked randomly.
The assumption is that the cracker knows your password scheme.
[[Special:Contributions/86.81.151.19|86.81.151.19]] 20:17, 28 April 2013 (UTC)
Willem

:I just wrote a program to bruteforce this password creation method. https://github.com/KrasnayaSecurity/xkcd936/blob/master/listGen936.py Once I get it I'll try coming up with more bruteforcing algorithms such as substituting symbols, numbers, camel case, and the like. Point is, don't rely on this or any one method. I wouldn't be surprised if the crackers are already working on something like this. [[User:Lieutenant S.|Lieutenant S.]] ([[User talk:Lieutenant S.|talk]]) 07:03, 8 September 2014 (UTC)
:It took 1.25 hours to bruteforce "correcthorsebatterystaple" using the 2,000 most common words with one CPU. [[User:Lieutenant S.|Lieutenant S.]] ([[User talk:Lieutenant S.|talk]]) 07:09, 9 September 2014 (UTC)
:: 1) ... as compared to 69 milliseconds for the other method. 2) Since you are able to test 3,9 billion passwords as second (very impressive!) I am guessing that your setup is not performing its attack over a ”weak remote service”, which is breaking the rules of the #936 game. 3) five words and a 20k-wordlist would get you 9400 years (still breaking the weak remote service rule).--[[User:Gnirre|Gnirre]] ([[User talk:Gnirre|talk]]) 09:13, 14 October 2014 (UTC)

Sometimes this is not possible. (I'm looking at you, local banks with 8-12 character passwords and PayPal) If I can, I use a full sentence. A compound sentence for the important stuff. This adds the capitalization, punctuation and possibly the use of numbers while it's even easier to remember then Randall's scheme. I think it might help against the keyloggers too, if your browser/application autofills the username filed, because you password doesn't stand out from the feed with being gibberish. [[Special:Contributions/195.56.58.169|195.56.58.169]] 09:01, 30 August 2013 (UTC)

The basic concept can be adapted to limited-length passwords easily enough: memorize a phrase and use the first letter of each word. It'll require about a dozen words (you're only getting 4.7 bits per letter at best, actually less because first letters of words are not truly random, though they are weakly if at all correlated with their neighbors -- based on the frequencies of first letters of words in English, and assuming no correlation between each first letter and the next, I calculate about 4 bits per character of Shannon entropy). SteveMB 18:35, 30 August 2013 (UTC)

Followup: The results of extracting the first letters of words in sample texts (the {{w|Project_Gutenberg|Project Gutenberg}} texts of ''The Adventures of Huckleberry Finn'', ''The War of the Worlds'', and ''Little Fuzzy'') and applying a {{w|Entropy_(information_theory)|Shannon entropy calculation}} were 4.07 bits per letter (i.e. first letter in word) and 8.08 bits per digraph (i.e. first letters in two consecutive words). These results suggest that first-letter-of-phrase passwords have approximately 4 bits per letter of entropy. --[[User:SteveMB|SteveMB]] ([[User talk:SteveMB|talk]]) 14:21, 4 September 2013 (UTC)

Addendum: The above test was case-insensitive (all letters converted to lowercase before feeding them to the [[http://millikeys.sourceforge.net/freqanalysis.html frequency counter]]). Thus, true-random use of uppercase and lowercase would have 5 bits per letter of entropy, and any variation in case (e.g. preserving the case of the original first letter) would fall between 4 and 5 bits per letter. --[[User:SteveMB|SteveMB]] ([[User talk:SteveMB|talk]]) 14:28, 4 September 2013 (UTC)

I just have RANDOM.ORG print me ten pages of 8-character passwords and tape it to the wall, then highlight some of them and use others (say two down and to the right or similar) for my passwords, maybe a given line a line a little jumbled for more security. [[Special:Contributions/70.24.167.3|70.24.167.3]] 13:27, 30 September 2013 (UTC)
:Remind me to visit your office and secretly replace your wall-lists by a list of very similar looking strings ;) --[[User:Chtz|Chtz]] ([[User talk:Chtz|talk]]) 13:53, 30 September 2013 (UTC)

Simple.com (online banking site) had the following on it’s registration page:

“Passphrase? Yes. Passphrases are easier to remember and more secure than traditional passwords. For example, try a group of words with spaces in between, or a sentence you know you'll remember. "correct horse battery staple" is a better passphrase than r0b0tz26.”

Online security for a banking site has been informed by an online comic. Astounding.
[[Special:Contributions/173.245.54.78|173.245.54.78]] 21:22, 11 November 2013 (UTC)

The Web service Dropbox has an Easter egg related to this comic on their sign-up page. That page has a password strength indicator (powered by JavaScript) which changes as you type your password. This indicator also shows hints when hovering the mouse cursor over it. Entering "Tr0ub4dor&3" or "Tr0ub4dour&3" as the password causes the password strength indicator to fall to zero, with the hint saying, "Guess again." Entering "correcthorsebatterystaple" as the password also causes the strength indicator to fall to zero, but the hint says, "Whoa there, don't take advice from a webcomic too literally ;)." [[Special:Contributions/108.162.218.95|108.162.218.95]] 15:17, 11 February 2014 (UTC)

The explanation said that the comic uses a dictionary[http://www.explainxkcd.com/wiki/index.php?title=936:_Password_Strength&oldid=59309]. In fact it's a word list, which seems similar but it's not. All the words in the word list must be easy to memorize. This means it's better not to have words such as ''than'' or ''if''. Also, it's better not to have homophones (''wood'' and ''would'', for example). The sentence ''dictionary attack'' doesn't apply here. A dictionary attack requires the attacker to use all the words in the dictionary (e.g. 100,000 words). Here we must generate the 17,592,186,044,416 combinations of 4 common words. Those combinations can't be found in any dictionary. At 25 bytes per "word" that dictionary would need 400 {{w|tebi|binary terabytes}} to be stored. [[User:Xhfz|Xhfz]] ([[User talk:Xhfz|talk]]) 21:37, 11 March 2014 (UTC)

This comic was mentioned in a TED talk by Lorrie Faith Cranor on in March 2014. After performing a lot of studies and analysis, she concludes that "pass phrase" passwords are no easier to remember than complex passwords and that the increased length of the password increases the number of errors when typing it. There is a lot of other useful information from her studies that can be gleaned from the talk. [http://www.ted.com/talks/lorrie_faith_cranor_what_s_wrong_with_your_pa_w0rd Link]. What she doesn't mention is the frequency of changing passwords - in most organizations it's ~90 days. I don't know where that standard originated, but (as a sys admin) I suspect it's about as ineffective as most of our other password trickery - that is that it does nothing. Today's password thieves don't bash stolen password hash tables, they bundle keyloggers with game trainers and browser plugins.--[[Special:Contributions/173.245.50.75|173.245.50.75]] 18:14, 2 July 2014 (UTC)
:: Lorrie Faith Cranor gets the random part of #936 word generation correct, which is great. Regarding memorizability, this study (https://cups.cs.cmu.edu/soups/2012/proceedings/a7_Shay.pdf) does not address #936. The study uses no generator for gibberish of length 11. Most comparable are perhaps two classes of five or six randomly assigned characters. None of the study's generators has 44 bits of entropy – its dictionary for the method closest to #936 – noun-instr – contains only 181 nouns. The article contains no discussion of the significance of these differences to #936. In her TED Lorrie Faith Cranor says ”sorry all you xkcd fans” which could be interpreted as judgement of #936, but there is no basis in the above article for that. It does however seem plausible that the report could be reworked to address #936. --[[User:Gnirre|Gnirre]] ([[User talk:Gnirre|talk]]) 10:42, 14 October 2014 (UTC)

:Password-changing frequency isn't about making passwords more ''secure'', but instead it's about ''mitigating the damage'' of a successfully cracked password. If a hacker gets your password (through any means) and your password changes every 90 days, the password the hacker has obtained is only useful for a few months at most. That might be enough, but it might not. If the hacker is brute forcing the passwords to get them, that cuts into the time the password is useful. --[[Special:Contributions/173.245.54.168|173.245.54.168]] 22:22, 13 October 2014 (UTC)
::However, brute-forcing gets much ''easier'' that way.
::Say the average employee is around for 10 years, which is reasonable for some companies , absurdly high for others, and a bit low for a family business. That's 40 password changes.
::Now if you have to remember another password every now and then, you sacrifice complexity, lest you forget it. A factor of 40 is like one character less. But how much shorter will the password be? It's more likely that it's gonna be 3 or 4 characters less. Congrats, you just a factor of 1000's for a perceived "mitigation", which doesn't even work. Pro attackers can vacuum your server in a DAY once they have the PW. [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:03, 4 December 2014 (UTC)

Just because you are required to have a password that has letters and numbers in it doesn't mean you can't make it memorable. When caps are required, use CamelCase. When punctuation is required, make it an ampersand (&) or include a contraction. When numbers are required, pick something that has significance to you (your birthday, the resolution of your television, ect.). Keep in mind that, if your phrase is an actual sentence, the password entropy is 1.1 bits per character (http://what-if.xkcd.com/34), so length is key if you want your password to be secure. (Though no known algorithm can actually exploit the 1.1 bits of entropy to gain time, so it might be more like 11 bits of entropy per word. Even then, my passwords have nonexistent and uncommon words in them, (like doge or trope), which also adds some entropy.) [[Special:Contributions/108.162.246.213|108.162.246.213]] 22:18, 1 September 2014 (UTC)
:Flip side of the story, the "capital plus small plus other char" policy doesn't make your password any safer.
:The German company T-online had an experimental gateway with the password, "internet". Now that sucked. No problem, tho, because that gateway wasn't accessible from outside. When they went live, they "improved" the password to "Internet1". There are still lots of these passwords around: first letter is a Cap, and the only non-alphabetic char is a 1 at the end. This doesn't add any entropy. [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:03, 4 December 2014 (UTC)
::[http://ask.metafilter.com/193052/Oh-Randall-you-do-confound-me-so#2779020 This] shows that about one third of all digits in a sample of passwords was "1" . [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:14, 4 December 2014 (UTC)
You can also troll the brute-force engine by using words from other languages, fictional books and video games.--[[User:Horsebattery|Horsebattery]] ([[User talk:Horsebattery|talk]]) 03:04, 3 November 2014 (UTC)
:That's a good idea; it adds to the entropy bits per word. If you really want to throw them off, mix different languages. Just don't use very well-known words; I'm sure the hackers have ''cojones'' and ''Blitzkrieg'' in their dictionaries. [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:03, 4 December 2014 (UTC)

Also, passwords that are 'hard to remember' are themselves a security vulnerability. A password reset scheme (or even a lockout scheme) is a vulnerability. The more it needs to be used, the harder it becomes to police that vulnerability. Relatedly, hard-to-remember passwords leave users uncertain whether their password has been changed by someone else or they've just forgotten it. [[User:Ijkcomputer|Ijkcomputer]] ([[User talk:Ijkcomputer|talk]]) 15:32, 18 December 2014 (UTC)

Talk:936: Password Strength

2014-12-18T15:32:01Z

Ijkcomputer:

You still have to vary the words with a bit of capitalization, punctuation and numbers a bit, or hackers can just run a dictionary attack against your string of four words. '''[[User:Davidy22|{{Color|purple|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 09:12, 9 March 2013 (UTC)

No you don't. Hackers cannot run a dictionary attack against a string of four randomly picked words.
Look at the number of bits displayed in the image: 11 bits for each word.
That means he's assuming a dictionary of 2048 words, from which each word is picked randomly.
The assumption is that the cracker knows your password scheme.
[[Special:Contributions/86.81.151.19|86.81.151.19]] 20:17, 28 April 2013 (UTC)
Willem

:I just wrote a program to bruteforce this password creation method. https://github.com/KrasnayaSecurity/xkcd936/blob/master/listGen936.py Once I get it I'll try coming up with more bruteforcing algorithms such as substituting symbols, numbers, camel case, and the like. Point is, don't rely on this or any one method. I wouldn't be surprised if the crackers are already working on something like this. [[User:Lieutenant S.|Lieutenant S.]] ([[User talk:Lieutenant S.|talk]]) 07:03, 8 September 2014 (UTC)
:It took 1.25 hours to bruteforce "correcthorsebatterystaple" using the 2,000 most common words with one CPU. [[User:Lieutenant S.|Lieutenant S.]] ([[User talk:Lieutenant S.|talk]]) 07:09, 9 September 2014 (UTC)
:: 1) ... as compared to 69 milliseconds for the other method. 2) Since you are able to test 3,9 billion passwords as second (very impressive!) I am guessing that your setup is not performing its attack over a ”weak remote service”, which is breaking the rules of the #936 game. 3) five words and a 20k-wordlist would get you 9400 years (still breaking the weak remote service rule).--[[User:Gnirre|Gnirre]] ([[User talk:Gnirre|talk]]) 09:13, 14 October 2014 (UTC)

Sometimes this is not possible. (I'm looking at you, local banks with 8-12 character passwords and PayPal) If I can, I use a full sentence. A compound sentence for the important stuff. This adds the capitalization, punctuation and possibly the use of numbers while it's even easier to remember then Randall's scheme. I think it might help against the keyloggers too, if your browser/application autofills the username filed, because you password doesn't stand out from the feed with being gibberish. [[Special:Contributions/195.56.58.169|195.56.58.169]] 09:01, 30 August 2013 (UTC)

The basic concept can be adapted to limited-length passwords easily enough: memorize a phrase and use the first letter of each word. It'll require about a dozen words (you're only getting 4.7 bits per letter at best, actually less because first letters of words are not truly random, though they are weakly if at all correlated with their neighbors -- based on the frequencies of first letters of words in English, and assuming no correlation between each first letter and the next, I calculate about 4 bits per character of Shannon entropy). SteveMB 18:35, 30 August 2013 (UTC)

Followup: The results of extracting the first letters of words in sample texts (the {{w|Project_Gutenberg|Project Gutenberg}} texts of ''The Adventures of Huckleberry Finn'', ''The War of the Worlds'', and ''Little Fuzzy'') and applying a {{w|Entropy_(information_theory)|Shannon entropy calculation}} were 4.07 bits per letter (i.e. first letter in word) and 8.08 bits per digraph (i.e. first letters in two consecutive words). These results suggest that first-letter-of-phrase passwords have approximately 4 bits per letter of entropy. --[[User:SteveMB|SteveMB]] ([[User talk:SteveMB|talk]]) 14:21, 4 September 2013 (UTC)

Addendum: The above test was case-insensitive (all letters converted to lowercase before feeding them to the [[http://millikeys.sourceforge.net/freqanalysis.html frequency counter]]). Thus, true-random use of uppercase and lowercase would have 5 bits per letter of entropy, and any variation in case (e.g. preserving the case of the original first letter) would fall between 4 and 5 bits per letter. --[[User:SteveMB|SteveMB]] ([[User talk:SteveMB|talk]]) 14:28, 4 September 2013 (UTC)

I just have RANDOM.ORG print me ten pages of 8-character passwords and tape it to the wall, then highlight some of them and use others (say two down and to the right or similar) for my passwords, maybe a given line a line a little jumbled for more security. [[Special:Contributions/70.24.167.3|70.24.167.3]] 13:27, 30 September 2013 (UTC)
:Remind me to visit your office and secretly replace your wall-lists by a list of very similar looking strings ;) --[[User:Chtz|Chtz]] ([[User talk:Chtz|talk]]) 13:53, 30 September 2013 (UTC)

Simple.com (online banking site) had the following on it’s registration page:

“Passphrase? Yes. Passphrases are easier to remember and more secure than traditional passwords. For example, try a group of words with spaces in between, or a sentence you know you'll remember. "correct horse battery staple" is a better passphrase than r0b0tz26.”

Online security for a banking site has been informed by an online comic. Astounding.
[[Special:Contributions/173.245.54.78|173.245.54.78]] 21:22, 11 November 2013 (UTC)

The Web service Dropbox has an Easter egg related to this comic on their sign-up page. That page has a password strength indicator (powered by JavaScript) which changes as you type your password. This indicator also shows hints when hovering the mouse cursor over it. Entering "Tr0ub4dor&3" or "Tr0ub4dour&3" as the password causes the password strength indicator to fall to zero, with the hint saying, "Guess again." Entering "correcthorsebatterystaple" as the password also causes the strength indicator to fall to zero, but the hint says, "Whoa there, don't take advice from a webcomic too literally ;)." [[Special:Contributions/108.162.218.95|108.162.218.95]] 15:17, 11 February 2014 (UTC)

The explanation said that the comic uses a dictionary[http://www.explainxkcd.com/wiki/index.php?title=936:_Password_Strength&oldid=59309]. In fact it's a word list, which seems similar but it's not. All the words in the word list must be easy to memorize. This means it's better not to have words such as ''than'' or ''if''. Also, it's better not to have homophones (''wood'' and ''would'', for example). The sentence ''dictionary attack'' doesn't apply here. A dictionary attack requires the attacker to use all the words in the dictionary (e.g. 100,000 words). Here we must generate the 17,592,186,044,416 combinations of 4 common words. Those combinations can't be found in any dictionary. At 25 bytes per "word" that dictionary would need 400 {{w|tebi|binary terabytes}} to be stored. [[User:Xhfz|Xhfz]] ([[User talk:Xhfz|talk]]) 21:37, 11 March 2014 (UTC)

This comic was mentioned in a TED talk by Lorrie Faith Cranor on in March 2014. After performing a lot of studies and analysis, she concludes that "pass phrase" passwords are no easier to remember than complex passwords and that the increased length of the password increases the number of errors when typing it. There is a lot of other useful information from her studies that can be gleaned from the talk. [http://www.ted.com/talks/lorrie_faith_cranor_what_s_wrong_with_your_pa_w0rd Link]. What she doesn't mention is the frequency of changing passwords - in most organizations it's ~90 days. I don't know where that standard originated, but (as a sys admin) I suspect it's about as ineffective as most of our other password trickery - that is that it does nothing. Today's password thieves don't bash stolen password hash tables, they bundle keyloggers with game trainers and browser plugins.--[[Special:Contributions/173.245.50.75|173.245.50.75]] 18:14, 2 July 2014 (UTC)
:: Lorrie Faith Cranor gets the random part of #936 word generation correct, which is great. Regarding memorizability, this study (https://cups.cs.cmu.edu/soups/2012/proceedings/a7_Shay.pdf) does not address #936. The study uses no generator for gibberish of length 11. Most comparable are perhaps two classes of five or six randomly assigned characters. None of the study's generators has 44 bits of entropy – its dictionary for the method closest to #936 – noun-instr – contains only 181 nouns. The article contains no discussion of the significance of these differences to #936. In her TED Lorrie Faith Cranor says ”sorry all you xkcd fans” which could be interpreted as judgement of #936, but there is no basis in the above article for that. It does however seem plausible that the report could be reworked to address #936. --[[User:Gnirre|Gnirre]] ([[User talk:Gnirre|talk]]) 10:42, 14 October 2014 (UTC)

:Password-changing frequency isn't about making passwords more ''secure'', but instead it's about ''mitigating the damage'' of a successfully cracked password. If a hacker gets your password (through any means) and your password changes every 90 days, the password the hacker has obtained is only useful for a few months at most. That might be enough, but it might not. If the hacker is brute forcing the passwords to get them, that cuts into the time the password is useful. --[[Special:Contributions/173.245.54.168|173.245.54.168]] 22:22, 13 October 2014 (UTC)
::However, brute-forcing gets much ''easier'' that way.
::Say the average employee is around for 10 years, which is reasonable for some companies , absurdly high for others, and a bit low for a family business. That's 40 password changes.
::Now if you have to remember another password every now and then, you sacrifice complexity, lest you forget it. A factor of 40 is like one character less. But how much shorter will the password be? It's more likely that it's gonna be 3 or 4 characters less. Congrats, you just a factor of 1000's for a perceived "mitigation", which doesn't even work. Pro attackers can vacuum your server in a DAY once they have the PW. [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:03, 4 December 2014 (UTC)

Just because you are required to have a password that has letters and numbers in it doesn't mean you can't make it memorable. When caps are required, use CamelCase. When punctuation is required, make it an ampersand (&) or include a contraction. When numbers are required, pick something that has significance to you (your birthday, the resolution of your television, ect.). Keep in mind that, if your phrase is an actual sentence, the password entropy is 1.1 bits per character (http://what-if.xkcd.com/34), so length is key if you want your password to be secure. (Though no known algorithm can actually exploit the 1.1 bits of entropy to gain time, so it might be more like 11 bits of entropy per word. Even then, my passwords have nonexistent and uncommon words in them, (like doge or trope), which also adds some entropy.) [[Special:Contributions/108.162.246.213|108.162.246.213]] 22:18, 1 September 2014 (UTC)
:Flip side of the story, the "capital plus small plus other char" policy doesn't make your password any safer.
:The German company T-online had an experimental gateway with the password, "internet". Now that sucked. No problem, tho, because that gateway wasn't accessible from outside. When they went live, they "improved" the password to "Internet1". There are still lots of these passwords around: first letter is a Cap, and the only non-alphabetic char is a 1 at the end. This doesn't add any entropy. [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:03, 4 December 2014 (UTC)
::[http://ask.metafilter.com/193052/Oh-Randall-you-do-confound-me-so#2779020 This] shows that about one third of all digits in a sample of passwords was "1" . [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:14, 4 December 2014 (UTC)
You can also troll the brute-force engine by using words from other languages, fictional books and video games.--[[User:Horsebattery|Horsebattery]] ([[User talk:Horsebattery|talk]]) 03:04, 3 November 2014 (UTC)
:That's a good idea; it adds to the entropy bits per word. If you really want to throw them off, mix different languages. Just don't use very well-known words; I'm sure the hackers have ''cojones'' and ''Blitzkrieg'' in their dictionaries. [[Special:Contributions/141.101.104.53|141.101.104.53]] 13:03, 4 December 2014 (UTC)
:Also, passwords that are 'hard to remember' are themselves a security vulnerability. A password reset scheme (or even a lockout scheme) is a vulnerability. The more it needs to be used, the harder it becomes to police that vulnerability. Relatedly, hard-to-remember passwords leave users uncertain whether their password has been changed by someone else or they've just forgotten it.