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Launchpad
It does come at the cost of some launchpad expansions and increased fuel requirements, but that all comes out of the facility's budget.
Title text: It does come at the cost of some launchpad expansions and increased fuel requirements, but that all comes out of the facility's budget.

    Explanation

    This comic is about launching a spacecraft into space, seen as a problem of separating the spacecraft from the Earth. Traditionally this is done by accelerating the spacecraft away from the Earth using a rocket, but in this comic it's done by accelerating the Earth away from the spacecraft. Instead of the rocket engines being part of the rocket, the engines are mounted upside-down on the launch platform, and by extension, on the planet Earth itself, apparently to accelerate the Earth away from the spacecraft.

    Even from a purely theoretical perspective this is difficult to achieve: the exhaust of the engines would be in Earth's gravitational field and thus be slowly pulled back towards it. According to Newtons's Third Law this would in turn cause the exhaust to pull the Earth backwards too, negating any thrust generated by the engines. To prevent this, the speed of the exhaust would have to exceed Earth's escape velocity (11.2 km/s), but neither solid fuel (2.5 km/s) nor liquid fuel (4.5 km/s) rockets do so. The presence of Earth's atmosphere exacerbates this: The interaction of the exhaust with the stationary atmosphere would dissipate the energy of the exhaust, lowering the speed of the moving gases. Thus the engines would have to exceed the escape velocity by a lot to be able to generate any thrust.

    Ignoring this, there would still be literally massive practical problems. Three main issues come from the same underlying fact: The Earth has a lot more mass than a typical spacecraft.[citation needed] This means that the engines would need to produce gigantic amounts of force, even by rocketry standards, to accelerate the Earth away from the spacecraft. Additionally, the structural integrity of the object experiencing the force (both the rocket engine and the ground) would be concerning, given the amount of force needed. In addition, the spacecraft would be unlikely to actually lift off the Earth if the planet were somehow moved, as the Earth's gravity would keep it in place; the Earth would need to be accelerated at more than one g (one gravity) to separate it from the spacecraft, causing widespread destruction to everything on the planet. In addition to the spacecraft, every other untethered object in approximately the same hemisphere would also separate, including the atmosphere. To what extent the spacecraft would ever be in space is debatable. And in addition to that, the rocket itself would still need some form of propulsion for maneuvering in space, thwarting the purpose of having the engines not attached to the spacecraft. (In multi-stage rocketry, the propulsion for use in space remains attached to the remaining part(s) of the rocket even after the first and heaviest element(s) of the rocket used to get out of the atmosphere are jettisoned to save weight once no longer needed. Nothing in the comic says that maneuvering thrusters and propellant are not present in the capsule, though one could also imagine the xkcd scenario keeping similarly supersized thrusters on Earth, somehow further maneuvering the planet beneath the free-floating capsule.)

    Finally, even if the Earth could be moved away from the spacecraft, the spacecraft would be directly in the exhaust stream of the (extremely powerful) engines, which would immediately incinerate it.

    The title text further ridicules the situation. Costs in an organization are sometimes split between project budgets, one for each project, and a facility budget, which might be shared by all the projects. In a space launch organization, each launch might have its own budget, with a separate budget for the launch facility that's shared by the projects. In this comic, Cueball is saying in effect that one shouldn't worry about the project's budget paying for moving the Earth, since the cost will come out of the facility budget. This assumes, amusingly, that the facility's budget will somehow cover the cost of physically moving the Earth. Of course, not only would it be unlikely anyone would have the budget to deal with this elaborate scheme, but it is also unlikely there would be enough resources, full stop, to generate the power needed to move the Earth. Possibly the facility is linked in with Beret Guy, which would make the venture more probable given his history of making bizarre things work.

    The comic 1366: Train demonstrated a similar Earth-moving principle; with the exception being that this other example could be considered feasible, albeit by adopting an unorthodox frame of reference.

    Transcript

    [Two giant twin engines are sitting on the ground pointing downwards, with a pod in between them. A Megan and a Ponytail are to the left of the first one, with a Cueball carrying something to the right of the thruster. Another Cueball is pointing to the pod from the right, talking to another Ponytail, and there is another Megan on the right side of the right thruster.]
    Second Cueball: To reduce the spacecraft´s weight, we´re mounting the engines on the launchpad and having them push the Earth away from the spacecraft.

    Trivia

    This comic is very similar to a 2016 Buttersafe comic where Jolly Octopus successfully pushes the Earth away from Saddest Turtle in this same manner.


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    This Week's Explanation for Improvement

    As part of the Explanation Improvement Project, each week the community selects one older, neglected, or otherwise stagnant explanation to expand and polish together. This week's pick is 380: Emoticon; please help us improve it! To get involved with the project, you can also nominate an explanation or vote on current nominations!

    Emoticon
    U+FDD0 is actually Unicode for the eye of the basilisk, though for safety reasons no font actually renders it.
    Title text: U+FDD0 is actually Unicode for the eye of the basilisk, though for safety reasons no font actually renders it.

      Explanation

      Welcome to This Week's Explanation for Improvement! Anyone is encouraged to help explain comic 380: Emoticon; click here to get started! If you are new to wiki editing, you can read our editing FAQ for guidance. Here are some suggestions for improving this explanation:

        Improve the existing trivia section, such as by adding that Cueball is not called Rob in this comic.
        Explain the reference in the username and link similar comics that feature chat clients.
        Give an historical background about old chatrooms and requests for A/S/L, which are now uncommon.

      A basilisk, originating in Greco-Roman antiquity, is a legendary creature reputed to have the power to kill any living creature with a single glance, or in other mentions, by turning the victim into stone (Shakespeare, in his Richard III play, uses the basilisk as a metaphor for something that kills). In this comic Cueball doesn't appear to be turned to stone in the comic.

      In this comic, Cueball, who goes by "NICKM" (possibly a reference to Harry Potter, see below), chats online with a user named "BSLSK05" via instant messaging. He quickly learns, much to his dismay, that he is chatting with an actual basilisk, who kills him by texting him a smiley emoticon (a colon and a closing parenthesis: :)), suggesting that the basilisk's power can extend beyond actual physical eye contact and is effective even with a mere visual representation of a pair of "basilisk" eyes as keyboard characters. This is humorous, as this parallels the power of the basilisk. Apparently, Cueball is merely killed rather than being turned to stone.

      The username "BSLSK05" is, of course, the word "basilisk" sans vowels and with appended numbers. Usually, appended numbers in a username denote the last two digits of the year for when the user was born. Years can hint to be at least in the 20th century, but in the case of the basilisk, it could be a lot earlier (although the lifespans of basilisks are unknown/unspecified in myths).

      This comic is possibly a reference to Harry Potter and the Chamber of Secrets of the novel and movie series Harry Potter, in which a basilisk is let loose in the school of Hogwarts. The character in the comic, "NickM", could refer to the character Nicholas de Mimsy-Porpington, also known as Nearly Headless Nick, a ghost who, in the story, becomes a victim of the basilisk's gaze. Since he is a ghost and has already died, he is instead rendered immobile, or in the book, "petrified".

      Another possible reference is the Basilisk monster from the Dungeons & Dragons Monster Manual. Here, the Basilisk is a monster with the special ability "Petrifying Gaze".

      Cueball's question, "A/S/L?", is an Internet shorthand for requesting one's age, sex, and location from another user. This was commonly used when first meeting someone online and was useful for getting some basic information about the user they were chatting with, especially to determine their compatibility with their chat partner in dating-based settings. The term has fallen out of style since the comic, with the introduction of sites such as Tinder and Omegle that showed such information up-front, either via profile descriptions or an image of their face (profile pictures). This allowed for, among other things, the ability to know a bit about the person before chatting with them, making this question almost entirely useless.

      Some more modern chat-only platforms, such as Emerald Chat, have birthed new introductory questions such as 'M or F' to ask a person's gender.

      The type of chat system pictured may likely be Internet Relay Chat (IRC), the earliest popular system used for instant messaging, as most IRC clients share the use of formatting usernames with surrounding angle brackets and prefixing event messages with "-!-".

      The title text refers to the Unicode character code point U+FDD0, which is a non-character — this specific one is permanently reserved for internal application processing rather than regular text, meaning no font sets support the character. If you attempt to render the character in a text field or editor, it would either not show up or would display as an empty box (□) or an invalid/missing character box (�). Unicode does, however, have many characters for representing images and icons/symbols, such as ✉ (Envelope), ☎ (Telephone), ✏ (Pencil), ✂ (Scissors), ⚙ (Gear), ★ (Star), ancient Egyptian glyphs, and (most popularly) emojis. The title text jokes that U+FDD0 is actually the character for the eye of a basilisk (which does not exist), but is not rendered by any fonts because it may kill anybody who looks at the character, i.e., for safety reasons.

      Transcript

      [Cueball sits at computer, typing. The computer screen reads as follows:]
      ~!~ Opening Chat with BSLSK05
      <NICKM> Hi!
      <NICKM> A/S/L?
      [The next panel is unframed, with two smaller frames within it.]
      <BSLSK05> :)
      [Cueball looks stunned, flies backward.]
      [The two smaller frames focus in on BSLSK05's emoticon, implying rotation to show a smile and two open eyes.]
      [Cueball at computer slouches in chair, dead, crossbones above his head.]
      [At the remote computer, a basilisk is looking at its screen, pleased with its endeavours.]

      Trivia

      The unicode character used as the eye of the basilisk, U+FDD0 did in fact kill at least one chat client, Konversation (and presumably any other Qt-based chat clients using QTextDocument). This was because U+FDD0 is one of the 32 non-characters located in the block “Arabic Presentation Forms-A” used "to make additional codes available to programmers to use for internal processing purposes". According to the Unicode FAQ they are reserved for internal (private) use.

      However, QT's UTF-8 encoder let it through anyway. But QT's qtextdocument uses U+FDD0 as text frame delimiter so when it is appended to a QTextDocument, counters run wrong and eventually it crashes.

      D-bus closes the connection and crashes the client when it encounters illegal UTF-8, and KDE's notification system works through d-bus.

      The problem was fixed after the xkcd "report" and Konversation now handles unicode normally.

      In this comic, Cueball is not referred to as Rob.


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