explain xkcd - User contributions [en]

1815: Flag

2017-03-24T16:42:30Z

Hello71:

{{comic
| number = 1815
| date = March 24, 2017
| title = Flag
| image = flag.png
| titletext = There's a compromise bill to keep the notification bar but at least charge the battery.
}}

==Explanation==
{{incomplete|Needs more detail on how flags and images in general are designed/edited using computers, and why what Randall did was wrong.}}

Randall was hired to propose a new flag for an unspecified new country. The process of him editing the flag into its final draft was done on a laptop or mobile device, and involved taking a screenshot of the product (possibly a shortcut to avoid actually exporting it) which produced the notification bar at the top of the flag. He did not catch his error, and sent it to the committee with the notification bar intact. The design committee could have fired Randall either for making the specific mistake, or because the mistake shed some light into the unprofessional way Randall is doing his job in general. The elements of the flag's intended design, the colors red white and blue, the stripes, and the stars, are present in several existing flags for real countries (America, the UK, North Korea, etc.) Flags are often minimalist and involve geometric shapes and solid colors. A notification bar at the top of the flag would clash with these design elements as well as looking unprofessional.

The title text mentions a compromise bill that will change the flag, not removing the notification bar at the top to create the originally intended flag, but instead keeping the notification bar and changing the amount of battery displayed (39%) to 100%. The low battery status might imply that the country is low on resources. Randall has mentioned before that he cannot take screenshots seriously if the battery of the device is low in [[1373: Screenshot]].

This comic is a joke on "vexillology".

==Transcript==

:[A picture is shown of a flag for a currently nonexistent country. The left and rightmost parts of the flag are dark blue, and the center is red. These parts of the flag are separated by white vertical stripes. In the center of each colored section of the flag is a large, white star. At the top of the flag, there is a conspicuous off-white notification bar like one you would find at the top of a laptop or phone. On the left it is displaying the strength of a 3G connection (3/5 dots), in the center it is displaying the time (5:43 PM) and on the right, it is displaying battery charge (39%)]
:The design committee fired me once they realized that my editing process involved a screenshot, but it was too late.
:Until they change it, our new country has the only national flag to include a phone notification bar.

{{comic discussion}}

1603: Flashlights

2015-11-13T15:23:16Z

Hello71: /* Transcript */

{{comic
| number = 1603
| date = November 13, 2015
| title = Flashlights
| image = flashlights.png
| titletext = Due to a typo, I initially found a forum for serious Fleshlight enthusiasts, and it turns out their highest-end models are ALSO capable of setting trees on fire. They're impossible to use without severe burns, but some of them swear it's worth it.
}}

==Explanation==
In this comic, [[Cueball]] has acquired or built a new high powered flashlight, which he wants to demonstrate to [[Megan]]. When Cueball refers to classic {{w|flashlights}} (battery torches) as dim and finnicky, this gives reason to assume that the flashlight he is holding is going to be ridiculously overengineered.

Indeed, when he switches it on outside the house, the intense light beam completely drowns out the scene. Only the reflected light from the forest lights up the part of Cueball and Megan's faces that are turned towards it.

Cueball comments that the flashlight lights up the entire forest, but Megan observes that it is the trees that are on fire, indicating that Cueball's flashlight is so overpowered that the energy of its beam is sufficient to cause the organic matter of trees to combust.

Of course, a flashlight that cannot safely be pointed at things is fairly useless for the traditional purpose of a flashlight, which would be to find things in the dark by directing light over them. This mundane and practical reasoning does not seem to matter to Cueball of course, who appears only interested in the intensity and brightness the device is capable of achieving.

The title text refers to {{w|Fleshlight}} a brand of male masturbation toys modeled after various female or male orifices. Cueball (or [[Randall]]) claims that he only arrived on a forum for Fleshlight enthusiasts due to a typo. An apart from the "e" vs. "a" in Fleshlight they are also fashioned to look like oversized flashlights. On that forum here he found out that the highest-end models of their product lines was also capable of setting trees on fire. This would probably happen due to violent vibrations inside the orifice. If you use one of these you should expect to obtain severe burns in a very unpleasant area. But some of the enthusiasts swears that it is still worth it, in the same manner as Cueball only cares about the intensity of the flashlight regardless of the consequences. Maybe they are just trying to trick you into doing something stupid!

Alternatively the wood they can set on fire is the male organ, and it is not real fire we are talking about. so it is actually a good commercial for the product. Of course if you use it too long you might gets burns...

One might wonder if Randall was first looking into Fleshlights and then found an interesting flashlight enthusiast page due to his typo the other way...

==Transcript==
:[Four panels are laid out horizontally.]

:[Panel 1: Cueball carries a flashlight walking towards Megan who is sitting on a couch]
:Cueball: Remember how flashlights sucked when we were kids? Always dim and finnicky?
:Megan: I guess?

:[Panel 2: Cueball and Megan walking to the left]
:Cueball: Well, I discovered there are now internet flashlight enthusiasts.
:Cueball: And the technology has... improved.
:Megan: OK, Let's see.

:[Panel 3: It is dark outside where Cueball turns on the flashlight. The beam is very bright and very visible even seen from the side. Backscattered light reflects off Cueball and Megan's faces, turning them into bright white beings in the dark. The facade of the house and the stairs are also visible in the same manner, with deep dark shadows where anything is in the shadow. Megan averts her face from the light holds up a hand to cover her eyes. When the flashlight turns on it even makes a sound, written in white above the beam:]
:Flashlight: '''''FWOOSH'''''

:[Panel 4: Cueball and Megan look at what the beam falls on (outside the frame). Megan has taken her hand down. Both their faces are only lit up like a crescent moon. Cueball is holding the flashlight with both hands as if it is pushing back on him. The text is written in white on the dark sky above them.]
:Cueball: See how it lights up the whole forest?
:Megan: ... The trees are on fire.
:Cueball: Real bright, though.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics with inverted brightness]]
[[Category:Sex]]

1546: Tamagotchi Hive

2015-07-03T14:00:04Z

Hello71: copy explanations of Tamagotchi and Distributed computing from wikipedia

{{comic
| number = 1546
| date = July 3, 2015
| title = Tamagotchi Hive
| image = tamagotchi_hive.png
| titletext = The Singularity happened, but not to us.
}}

==Explanation==
A Tamagotchi is a keychain-sized virtual pet simulation game for people of all ages. The characters are colorful and simplistically designed creatures based on animals, objects, or people. Beginning with the 2004 Tamagotchi Plus/Connection, a second wave of Tamagotchi toys emerged, featuring a different graphic design by JINCO and gameplay which elaborated upon the first generations. However, the story behind the games remained the same: Tamagotchis are a small alien species that deposited an egg on Earth to see what life was like, and it is up to the player to raise the egg into an adult creature. The creature goes through several stages of growth, and will develop differently depending on the care the player provides, with better care resulting in an adult creature that is smarter, happier, and requires less attention. Gameplay can vary widely between models, and some models, such as TamagoChu, require little to no care from the player. Tamagotchi has a large fan base. [https://en.wikipedia.org/wiki/Tamagotchi]

Distributed computing is a field of computer science that studies distributed systems. A distributed system is a software system in which components located on networked computers communicate and coordinate their actions by passing messages. The components interact with each other in order to achieve a common goal. Examples of distributed systems vary from SOA-based systems to massively multiplayer online games to peer-to-peer applications. [https://en.wikipedia.org/wiki/Distributed_computing]

==Transcript==
My Hobby

[Tree graph of Tamagotchis, representing connected users' systems]

Running a massive distributed computing project that simulates trillions and trillions of Tamagotchis and keeps them all constantly fed and happy

{{comic discussion}}

1181: PGP

2015-06-04T02:33:15Z

Hello71: /* Explanation */

{{comic
| number = 1181
| date = March 4, 2013
| title = PGP
| image = pgp.png
| titletext = If you want to be extra safe, check that there's a big block of jumbled characters at the bottom.
}}

==Explanation==
{{w|Pretty Good Privacy|PGP}} (Pretty Good Privacy) is a program which can be used to encrypt and/or sign data, including messages sent as emails. Encrypting means encoding data in a way that requires a secret key to decrypt and read; signing means that there is a code included in the data which can be used to verify the identify of the sender and that the data has not been altered in transit.

In the case of the email in this comic, it has only been signed; not encrypted (hence, the top of the first line of text can be seen and is legible in normal English). This is more common than encryption, as reading an encrypted message would require the recipient to already be a PGP user. In fact, the use of PGP even to sign email messages is so rare that most people have probably never seen a signed message. Because a signed email is so rare, and because it is already legible and unencrypted, [[Randall]] is making the tongue-in-cheek observation that few users, technical or otherwise, actually know how to use the signature to verify the authenticity of the sender using the PGP signature, and that such users can safely assume that since there ''is'' a signature, that is good enough evidence that the message is authentic. Further, because PGP signatures are so rare and probably ignored by most recipients, he suggests one would not expect anyone to even bother creating a false PGP signature; therefore the mere existence of a PGP header would suggest authenticity.

The title text extends the joke by suggesting you confirm there's a bunch of random characters in the footer (this is the actual signature that PGP generates which can be used to verify the authenticity of the email). Again, Randall is humorously suggesting that the existence of the block is itself sure evidence of authenticity.

==Transcript==
:How to use PGP to verify that an email is authentic:
:Look for this text at the top
:[In mail header, light grey.] Reply
:[Highlighted, with arrow pointing to it from the text "Look for this text at the top" above.]
:-----BEGIN PGP SIGNED MESSAGE-----
:[In mail message, light grey.]
:HASH: SHA256
:Hey,
:First of all, thanks for taking care of

:[After mail message.]
:If it's there, the email is probably fine

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Computers]]
[[Category:Cryptography]]

1523: Microdrones

2015-05-11T13:23:33Z

Hello71:

{{comic
| number = 1523
| date = May 11, 2015
| title = Microdrones
| image = microdrones.png
| titletext = Oh, weird, Amazon is out of butterfly nets.
}}

==Explanation==
{{incomplete|New page}}

[[File:AmazonPrimeAir.jpeg|200px|thumb|right|A drone from Amazon]]

{{w|Amazon Prime Air}} is a conceptual drone-based delivery system currently in development by Amazon.com. Later on, [[Cueball]] worries about living in an sci-fi dystopia, with those drones flying all around him, tracking his actions, etc. In the second panel, [[Megan]] suggests to send a message to Congress, suggesting a law for making the stealing of drones legal. This would alleviate the problem of drones flying around everywhere because people would catch them to use for themselves.

This tactic may not work as well as planned; drones will likely simply fly higher or employ other security measures since there are no regulations on drone behavior.

The title text suggests that Amazon is out of stock of butterfly nets due to everyone purchasing them to catch drones with.

==Transcript==
:[Cueball is standing behind Megan who sits at a desk typing on her laptop.]
:Cueball: So how do we regulate all these micro drones?
:Cueball: I mean, Amazon delivery bots sound cool...

:[Cueball stands alone surrounded by three micro drones.]
:Cueball: But I worry that overnight we'll realize we're surrounded by these things, no one will know who's controlling them, and then ''bam'', sci-fi dystopia.

:[Megan turns in her chair towards Cueball.]
:Megan: If you wanna slow it down, why not just remove all regulations, but then make drone theft legal?

:[Cueball takes his hand to his chin and Megan turns back to type on the laptop.]
:Cueball: ...I ''like'' that.
:Megan: You write to congress.
:Megan: I'll stock up on butterfly nets.

{{comic discussion}}


[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]

371: Compiler Complaint

2013-10-22T00:47:44Z

Hello71: Undo revision 46735 by Dgbrt (talk)

{{comic
| number = 371
| date = January 16, 2008
| title = Compiler Complaint
| image = compiler_complaint.png‎
| titletext = Checking whether build environment is sane... build environment is grinning and holding a spatula. Guess not.
}}

==Explanation==
A {{w|Compiler|compiler}} is a program that converts code into machine instructions that a computer can run. A {{w|Pointer (computer programming)|Pointer}} is a {{w|Variable (computer science)|variable}} within a computer program that is used to reference a memory location. A {{w|Segmentation Fault|Segmentation Fault (segfault)}} is an error that occurs when a program attempts to access an invalid section of memory. Segfaults usually cause a program to crash in an ungraceful fashion and fixing them can be difficult.

In the comic, the computer starts talking to [[Cueball]] and compares a segfault with the unpleasant feeling one gets when they experience a {{w|Hypnic jerk|hypnic jerk}}. The computer then tells the programmer to "double-check your damn pointers," as segfaults usually arise from a program attempting to access memory that is referenced by an invalid pointer.

The title-text references GNU-style {{w|autoconf}} configuration scripts. These scripts check certain features of the system they're running on in order to build a program correctly; for example, certain systems expect system calls to occur in a specific way, and the autoconf script will detect this and alter the program to match the expectation. Invariably (and memetically), these scripts include a check to determine "whether the build environment is sane." This actually checks whether a newly created file is older than the script itself, which could indicate a very esoteric filesystem, a corrupted source archive, or just a system clock that's set incorrectly; however, since these file modification dates are an important part of how the autoconf script does its work, it can't go any further in an "insane" environment. In any case, the joke is that an insane build environment is nothing like an insane person, yet Randall is equating the two.

==Transcript==
:[Cueball sits at a computer, hand over the keyboard.]
:Computer: Okay, human.
:Cueball: Huh?
:Computer: Before you hit "compile," listen up.

:Computer: You know when you're falling asleep, and you imagine yourself walking or something, and suddenly you misstep, stumble, and jolt awake?
:Cueball: Yeah!

:Computer: Well, that's what a segfault feels like.
:Computer: Double-check your damn pointers, okay?

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Programming]]
[[Category:Computers]]

File:sopa hidden message.png

2013-07-24T02:43:55Z

Hello71: /* Summary */

== Summary ==
Image from comic [[1005: SOPA]] (source: http://imgs.xkcd.com/comics/sopa.png), with a luminosity level change (0-4 expanded to 0-255) to reveal the message hidden inside it.

== Licensing ==
{{XKCD file derived}}

[[Category:Helper comic images]]

File:sopa hidden message.png

2013-07-24T02:43:37Z

Hello71: Hello71 uploaded a new version of "File:sopa hidden message.png": For the hell of it, let's run it through OptiPNG.

== Summary ==
Image from comic [[1005: SOPA]] (source: http://imgs.xkcd.com/comics/sopa.png), with a luminosity level change (0-10 expanded to 0-255) to reveal the message hidden inside it.
== Licensing ==
{{XKCD file derived}}

[[Category:Helper comic images]]

File:sopa hidden message.png

2013-07-24T02:42:17Z

Hello71: Hello71 uploaded a new version of "File:sopa hidden message.png": Use 0-4 instead of 0-10 to improve readability. (heh)