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We have an explanation for all 3319 xkcd comics, the 21 extra comics, and everything xkcd-related.Only 64 explanations (1.9%) are incomplete. Help us finish them!
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Latest comic
- Not to be confused with 288: Elevator.
| Elevators |
 Title text: "A reusable elevator would also be great because we'd save so much on the bulky and expensive shields that people currently use to avoid bruises and rug burns when sliding down the stairs." |
Explanation
This comic imagines what would happen if elevators were named literally, and hence could only go up (elevate themselves), resulting in them being single use, like a rocket going to space. It shows the elevators that have reached the end of their upward journey being ejected out of the top of the building, and then crashing into a heap on the ground. This means that an elevator must be repaired or purchased and (re-)installed every time someone in the building wants to go up. In a typical modern elevator, the cars go up and down for the entire life of the elevator system, which can be decades. Re-use is not an issue because a real-world elevator car is normally suspended from cables attached to its top or a hydraulic cylinder at the bottom.
Some early lift designs did come somewhat closer to the concept of the disposable car elevator. A paternoster lift uses a continuous chain of elevator cars moving at a slow fixed speed as an alternative to the single car design. A paternoster avoids the need for any form of floor alignment or the car calling and control system, which required either an expensive (for the time) relay-based responsive system or an attendant riding in the elevator. Paternoster lifts were popular when the cost of single-car control systems outweighed those of a chain of cars and the accessibility/safety issues of passengers boarding them in motion.
One concept for a disposable lift elevator could be conceptually similar to a single direction paternoster, where a car is lifted a fixed height (i.e. one 'floor') and then held in place while a new car is installed below it. When that car is raised to the same height it pushes the first car up another floor. This creates a single upwardly-moving stack of cars with the topmost car being ejected out of the chute when it reaches the top floor. This could be justified under certain demand scenarios where there will always be a load ready for the next car and a one-floor lift mechanism is the only option available. This system would work in asimilar way to the self-assembly of construction cranes or the construction technique of climbing formwork. Under this highly optimistic scenario, the simple cars could probably be returned for reuse via an out-of-band process like a slide or zipline.
The comic is probably a parodic commentary on the difference between expendable spacecraft which, for a long time, were the only real means to access space, and reusable spacecraft, which have only fairly recently been developed in earnest, and have significant or (potentially) full reusability, aside from the fuel load and any cargo. A space elevator would be even more like the 'non-disposable' travel system that this comic's characters apparently hope for, but the comic does not reference these directly.
The title text notes that another advantage of elevators that go down as well as up is that people don't need to find another means to descend from the upper floors of the building. Apparently, rather than make the lengthy walk down the stairs, people had been sliding down them, which was presumably faster and less tiring. However, it necessitated the use of shields (which they presumably had to take up with them in the elevator) to prevent injuries from friction burns and blows due to the uncontrolled descent. This parodies the use of shields in space travel to protect against heating during re-entry and impacts on landing.
Transcript
- [Cueball and Megan, both shown very small and barely recognizable, are standing at the bottom of a skyscraper which has eight rows of windows above the ground floor. On the roof of the building is a chute ejecting an elevator, as a dotted line shows the path of the elevator falling from the chute towards the ground. On the ground is a pile of crumpled elevators.]
- Cueball: It's such a waste.
- Megan: If only there were a way to bring them back down intact.
- [Text below the panel:]
- Skyscrapers were a lot less economical before the development of the reusable elevator.
Trivia
This is the first comic about elevators since 897: Elevator Inspection.
This Week's Explanation for Improvement
As part of the Explanation Improvement Project, each week the community selects one older, stagnant, or otherwise neglected explanation to expand and polish together. This week's pick is comic 301: Limerick, you can help us by editing its explanation!
To get involved with the project, you can also nominate an explanation that you think should be improved, or vote on current nominations!
| Limerick |
 Title text: Fun game: try to post a YouTube comment so stupid that people realize you must be joking. (Hint: this is impossible) |
Explanation
|
Welcome to This Week's Explanation for Improvement! Anyone is encouraged to help explain comic 301: Limerick; 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: .svg){kind=icon} Explain the title text about idiotic YouTube comments. This was also covered in comic 202: YouTube.
.svg){kind=icon} Why do the upvoted sarcastic comments make Cueball spiteful?
.svg){kind=icon} This comic's number (#301) is a reference to YouTube views getting stuck at 301. Learn what caused this bug and help explain it!
.svg){kind=icon} Make the explanation of a limerick more understandable.
.svg){kind=icon} The reference to Poe's law is interesting, expand on it.
.svg){kind=icon} Slashdot is no longer relevant after almost 20 years. Explain what it was and its eventual downfall (see Slashdot on Wikipedia)
|
A limerick is a well-known type of poem that is usually humorous or bawdy. A limerick is five lines long and has the rhyme scheme AABBA; the first, second, and fifth lines share one rhyme, while the third and fourth lines share another rhyme. Also, the third and fourth lines are usually shorter. Limericks primarily feature anapestic (◡◡–) and/or amphibrachic (◡–◡) trimeters. Almost anyone can instantly recognize a limerick after hearing the first line.[citation needed]
In poetry, a foot is a pattern unit of stressed (–) and unstressed (◡) syllables in a line. A meter measures the amount of feet per line. In this case, an 'anapestic trimeter' is a line of three anapests, where an 'anapest' is a foot that consists of two unstressed syllables followed by a stressed syllable.
Slashdot is a venerable techie site. On many sites, the user base can vote comments 'up' or 'down', but at Slashdot only moderators (randomly drawn from the pool of registered users) may up- or downvote comments, and the moderator may select a reason for their up- or downvote. Instead of a simple +1, a comment may be voted +1 (Funny). Similarly, instead of -1, a comment may be voted -1 (Off-topic). +5 is the maximum positive score. A comment rated +5 (Insightful) has been upvoted at least five times, and has a plurality of 'Insightful' votes.
Cueball's limerick says that he does not like Slashdot any more, because his sarcastic comments are being treated as 'insightful' by the very people he's being sarcastic to. A scansion for this poem (in the macron and breve notation) is as follows:
| Line (w/ highlighted stress) | Scansion | Term |
|---|---|---|
| I used to find Slashdot delightful | ◡–◡◡–◡◡–◡ | amphibrachic trimeter |
| but my feelings of late are more spiteful; | ◡◡–◡◡–◡◡–◡ | brachycatalectic amphibrachic trimeter or amphibrachic trimeter with a "pickup" |
| my comments sarcastic | ◡–◡◡–◡ | amphibrachic dimeter |
| the iconoclastic | ◡–◡◡–◡ | amphibrachic dimeter |
| keep modding to plus five (Insightful) | ◡–◡◡–◡◡–◡ | amphibrachic trimeter |
The title text refers to the notoriously awful comments on YouTube, many of which are so idiotic that they're interpreted as jokes.
In both cases, the comic is invoking Poe's Law. Both sites have become so full of extremes that you can no longer mock the extremists without looking like a sincere extremist yourself.
301, the number of this comic, is also a number often associated with YouTube. At the time this comic was published, view counts on YouTube videos would often freeze at 301, as YouTube would switch between view-counting algorithms when the number of views exceeded 300. Therefore, the comic number itself may be a reference to the title text.
Transcript
- [Cueball sits at a computer, typing.]
- Cueball (typing): I used to find Slashdot delightful,
- Cueball (typing): but my feelings of late are more spiteful;
- Cueball (typing): my comments sarcastic
- Cueball (typing): the iconoclastic
- Cueball (typing): keep modding to plus five (Insightful).
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