explain xkcd - User contributions [en]

3058: Tall Structures

2025-03-04T07:24:25Z

UkulelesRule:

{{comic
| number = 3058
| date = March 3, 2025
| title = Tall Structures
| image = tall_structures_2x.png
| imagesize = 740x430px
| noexpand = true
| titletext = Briefly set a new record for tallest human-made structure by getting my knit sweater snagged on the skydiving plane door as I jumped and not noticing until I'd landed.
}}

==Explanation==
{{incomplete|Created by a BOT ON TOP OF A SPACE ELEVATOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This is a comparison of various tall buildings and structures, ranging from a pyramid of Giza to the Burj Khalifa. [[Randall]]'s definition of a structure apparently takes from amongst those artificial objects that have continuous extent from the ground to some height.

The buildings are sorted by height. The tallest structure (under Randall's terms) is an {{w|aerostat}} balloon, which significantly exceeds the height of the Burj Khalifa.

{| class="wikitable" style="margin:auto"
|-
! Name !! Height !! {{w|List_of_tallest_buildings_and_structures#History|Tallest structure}} !! Explanation
|-
| {{w|Great Pyramid of Giza|The Great Pyramid}} (Giza) || 137 m (449.5 ft) || style="text-align:center" | 2570 BC–1311 AD || A famous pyramid built c. 2570 BC
|-
| {{w|The Shard}} (London) || 309.6 m (1,016 ft) || style="text-align:center" | – || A skyscraper with steeply angled sides, the tallest 'habitable freestanding structure' in the UK.
|-
| The {{w|Eiffel Tower}} (Paris) || 330 m (1,083 ft) || style="text-align:center" | 1889–1930 || A wrought-iron lattice tower named after its designer, Gustave Eiffel
|-
| The {{w|Empire State Building}} (New York) || 443.2 m (1,454 ft) || style="text-align:center" | 1931–1967 || An art-deco office tower often seen in media
|-
| The {{w|CN Tower}} (Toronto) || 553.3 m (1,815 ft) || style="text-align:center" | – || A communication and observation tower in Canada
|-
| {{w|The Clock Towers}} (Mecca) || 601 m (1,972 ft) || style="text-align:center" | – || A hotel complex featuring the largest clock in the world
|-
| {{w|KRDK-TV mast}} (North Dakota) || 630 m (2,060 ft) || style="text-align:center" | – || Current tallest structure in the United States ({{w|KVLY-TV mast
}} was previously taller)
|-
| {{w|Shanghai Tower}} (Shanghai) || 632 m (2,073 ft) || style="text-align:center" | – || Tallest skyscraper in China
|-
| {{w|Tokyo Skytree}} (Tokyo) || 634.0 m (2,080 ft) || style="text-align:center" | – || Tallest tower in the world
|-
| {{w|Merdeka 118}} (Kuala Lumpur) || 678.9 m (2,227 ft) || style="text-align:center" | – || A skyscraper with diamond-shaped facades
|-
| {{w|Burj Khalifa}} (Dubai) || 828 m (2,717 ft) || style="text-align:center" | 2007–present || Tallest structure in the world
|-
| Some random {{w|aerostat}} that happens to be operating today || ~1,280 m (4,200 ft) (Depicted)<br>{{w|Tethered Aerostat Radar System#System|~4,600 m (15,000 ft)}} (Actual) || style="text-align:center" | Varies || An aerostat is a lighter-than-air aircraft that can be tethered to the ground. This is the main joke of the comic, as as long as it is tethered to the ground and is higher than the Burj Khalifa, it could be considered the tallest man-made "building". However, the comic underestimates how high tethered aerostats can actually fly.
|}

The joke in the title text is that Randall once skydived out of an airplane wearing a knit sweater. The sweater caught on the airplane door, and presumably unravelled as he descended. When he reached the ground, the long thread that extended up to the plane (typically 8,000 to 14,000 feet above the ground) set a temporary record for the tallest structure. This is not realistically feasible, since knit tops usually only use around 1000 m (3280 ft) of yarn if knit using thin fingerling weight yarn. However, a sweater knit at a T-shirt density could in fact use over 2000 m (6561 ft) of yarn, which (assuming it hasn't started felting) is enough to extend to skydiving height.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Labels below structures shown in a black silhouette, from left to right, shortest to tallest:]
:The Great Pyramid (Giza)
:The Shard (London)
:The Eiffel Tower (Paris)
:The Empire State Building (New York)
:The CN Tower (Toronto)
:The Clock Towers (Mecca)
:KRDK-TV Mast (North Dakota)
:Shanghai Tower
:Tokyo Skytree
:Merdeka 118 (Kuala Lumpur)
:Burj Khalifa (Dubai)
:Some random aerostat that happens to be operating today

:[Caption below the panel:]
:The Burj Khalifa is the world's tallest artificial structure, but only on days when no one is flying a high-altitude balloon aerostat.

{{comic discussion}}

2801: Contact Merge

2023-07-13T09:19:06Z

UkulelesRule: /* Explanation */ one sentence!

{{comic
| number = 2801
| date = July 12, 2023
| title = Contact Merge
| image = contact_merge_2x.png
| imagesize = 353x429px
| noexpand = true
| titletext = I actually kind of feel like John and Surf King wouldn't like each other, which is a lot to unpack.
}}

==Explanation==
{{incomplete|Created by YOUR OTHER FRIEND WHO EDITS EXPLAINXKCD - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Cueball knows a friend by both a nickname in a group chat, and their real name, but hasn't realised that they are the same person until his smartphone, more astute than him, notices the details are the same and attempts to merge them in his phone's contacts.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

[Cueball chatting in DMs]

Cueball: @Surf_king Weird my phone keeps trying to merge your contact with John's

Surf_king: ...

Cueball: Hey you two should meet up-He's into surfing too

Surf_king: Oh my God

Surf_king: Are you serious

Surf_king: You've been in this chat with me for '''four years!'''

[Caption below the panel:]

I wonder who holds the record for accidentally doing this the longest

{{comic discussion}}

2786: UFO Evidence

2023-06-07T18:20:53Z

UkulelesRule: Added a bit more explanation, a citation needed joke would probably work here

{{comic
| number = 2786
| date = June 7, 2023
| title = UFO Evidence
| image = ufo_evidence_2x.png
| imagesize = 340x422px
| noexpand = true
| titletext = [Decades in the future] "Well, the good news is that we've received definitive communication from aliens. The bad news is that they're asking about Cats (2019)."
}}

==Explanation==
{{incomplete|Created by a ANATOMICALLY INCORRECT CAT WITH A NEED THAT WILL NOT BE SATISFIED. Do NOT delete this tag too soon.}}

A [[wikipedia:Ufology|UFOlogist]] accuses [[Cueball]] of being unwilling to listen to his claims for extraterrestrial life. UFO stands for "unidentified flying object" but is used in common parlance to mean a spaceship carrying beings from another planet. Cueball counters by admitting he once spent an entire afternoon trying to confirm the existence of a version of [[wikipedia:Cats_(2019_film)|Cats]] which allegedly gave the eponymous anthropomorphic felines anatomically-correct rear ends. The implication is that he's able to take any vaguely plausible claim at least a ''little'' seriously, but UFO claims don't even reach that bar.

Cueball's response suggests that he is keen to analyse even the most frivolous claim, such as the claim that there was an edit of the movie version of the musical Cats where the characters had visible anuses. He is suggesting to White Hat that if his "evidence" were at all compelling, Cueball would change his mind immediately, because the thought of viewers wanting to watch CGI cats played by human actors with the "uncanny valley" realism of an anatomically correct anus seems so absurd that it would be hard to imagine that filmmakers choose to animate them that way. Other animated movies with animal characters typically do not feature parts of an animal that would be considered unacceptable for a human to show.

The fact that Cueball was willing to believe this absurdity on presentation of good evidence suggests that even the thought of visitors from other planets - something that has been often reported but never officially confirmed - would be something he could believe if he felt that White Hat had genuine evidence.

The comic probably pertains to U.S. Air Force veteran and former {{w|National Geospatial-Intelligence Agency}} member [https://www.newsnationnow.com/space/ufo/lawmakers-react-to-whistleblowers-ufo-claims/ David Grusch], who is seeking whistleblower status for his claims that the U.S. government is hiding crashed alien spacecraft and corpses.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:White Hat: You scientists aren't willing to take my UFO evidence seriously!
:Cueball: I once spent a whole day trying to confirm the existence of a director's cut of ''Cats'' (2019) where the cats had anatomically correct CGI butts.
:Cueball: It's honestly embarrassing how fast I'd do a 180 if your evidence seemed promising.

{{comic discussion}}