explain xkcd - User contributions [en]

3038: Uncanceled Units

2025-01-15T15:09:45Z

108.162.216.113: /* Explanation */ added note

{{comic
| number = 3038
| date = January 15, 2025
| title = Uncanceled Units
| image = uncanceled_units_2x.png
| imagesize = 323x355px
| noexpand = true
| titletext = Speed limit c arcminutes^2 per steradian
}}

==Explanation==
{{incomplete|Created by THE PLANCK CONSTANT, WHICH IS TECHNICALLY A FREQUENCY AND CAN THUS BE EXPRESSED IN HERTZ - Please continue to explain the joke and possible interpretations. Do NOT delete this tag too soon.}}
Another of [[Randall]]'s [[:Category:Pet Peeves|pet peeves]], this comic expresses disapproval of units that could be mathematically simplified.

In this comic, [[White Hat]] is presenting a refrigerator to [[Cueball]], claiming it only uses 3 kWh per day. This is a commonly used, but uncancelled unit: kiloWatts x hour / day contains two units of time, which can be cancelled (24h = 1d), yielding 1/8 kW or 125 W. White Hat is expressing the refrigerator's power consumption as a unit of energy divided by time, but his choice of energy unit, kilowatt hour, is itself a unit of power times time (as opposed to the standard unit for energy, the Joule). Whilst this way of expressing energy consumption may be jarring to a scientific purist, it may well be preferred by an ordinary consumer as electricity is generally priced in kWh, allowing an easy conversion into currency to understand how much the refrigerator will cost to run each day.

Cueball (possibly representing Randall) answers by asking whether the refrigerator would fit in his kitchen, since the ceiling is only 50 gallons per square foot high, which is also an uncancelled unit, as gallons can be transformed to cubic feet (1 US gal ≈ 0.1337 ft<sup>3</sup>), which can be divided by the square feet, yielding a ceiling height of around 203.7 cm, or around 6 feet 8 inches. (Using imperial gallons [1 UK gal ≈ 0.1605 ft<sup>3</sup>], the height is approximately 244.7 cm, roughly 8 feet.) Cueball's unit is much less common and was likely deliberately chosen to be harder to understand, which shows how Randall feels about people using other uncancelled units like "kWh per day".

''[[what if? (blog)|what if?]]'': [https://what-if.xkcd.com/11/ Droppings] also covers strange instances of unit cancellation, including a measure of volume per distance converted to area; similar to Cueball's measure of volume per area representing a distance (the height of his ceiling).

In the title text, a speed limit is given as c arcminutes^2 per steradian, where c is presumably the speed of light in vacuum, 2.998×10^8 m/s (meters per second) or 186282 mi/s (miles per second). A steradian (sr) is the SI unit for solid angle, subtending a section of a sphere, like a radian is a unit of angle subtending a section of a circle. A square arcminute is also a unit of solid angle, equivalent to a section of a sphere of 1/60 of a degree by 1/60 of a degree. There are ((1/60)*(pi/180))^2 = 8.462×10^-8 sr in a square arcminute. Then multiplying by c gives a speed of 56.75 mph (probably 55 mph, based upon the {{w|National Maximum Speed Law|'traditional' US speed limit}}, before rounding errors in the reverse direction), or 91.33 km/h, showing that you can combine an outrageously high speed with two unnecessary units that cancel each other to form a normal road speed.

It is worth noting that although some of these examples are ridiculous, uncancelled units can be helpful to better understand the concept, the Hubble Constant (or Parameter) can be expressed as 2.17132212e-18 hertz, 67 km/sec/Mpc is directly related to how it is measured and gives a better understanding of what it means. Another example would be fuel efficiency in cars, as mi/gal and km/l technically simplify to ares, but by expressing it in volume and distance it allows easy estimations of range and travel cost, while mm^2 or in^2 would require significant unit conversions.

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

:[White Hat and Cueball are standing to either side of a refrigerator. The fridge has two top compartments and one bottom compartment. The top left compartment has a tall handle on its right, the top right compartment has a tall handle on its left, and the bottom compartment has a long handle on its top. The top left compartment has a paper attached to it with unreadable text, possibly an advertisement.]
:White Hat: This fridge uses only 3 kWh per day!
:Cueball: But will it fit in my kitchen? The ceiling there is only 50 gallons per square foot.

:[Caption below the panel:]
:Pet peeve: Uncanceled units

{{comic discussion}}

[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Math]]
[[Category:Pet Peeves]]

2604: Frankenstein Captcha

2022-04-09T03:34:52Z

108.162.216.113: /* Transcript */

{{comic
| number = 2604
| date = April 8, 2022
| title = Frankenstein Captcha
| image = frankenstein_captcha.png
| titletext = The distinction between a ship and a boat is a line drawn in water.
}}

==Explanation==
{{incomplete|Created by Rated Argh -Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic strip is a play on the meanings (and misunderstanding) of the name "Frankenstein". ''{{w|Frankenstein; or, the Modern Prometheus}}'' is an 1818 novel by Mary Shelley about a medical student named Victor Frankenstein who creates an artificial life-form. The man he creates once describes himself as "the Adam of your [Frankenstein's] labour" in the book, and strictly speaking is properly known as "Frankenstein's ''monster''" (or perhaps "creation" or "son"), but is often erroneously called "Frankenstein" himself.

The Captcha shown in the comic instructs the user to select all tiles containing Frankenstein. The tiles include both a reanimated corpse resembling Frankenstein's monster and a scientist yelling, "It's alive!” who is clearly intended to be Victor Frankenstein. The problem arises from the contrast between various definitions of the term Frankenstein. Going just off the book's text, the monster has no name, so the correct answer to the Captcha is just the left square of the third row. However, modern people often call the monster Frankenstein out of mistake or indifference, and some even argue that the monster should inherit its creator's surname. And in comic [[1589]], Randall created a version of the story where Frankenstein was the monster's name, and the doctor was unnamed. Also, if the images in the squares are scenes from the famous {{w|Frankenstein (1931 film)|1931 film}} starring {{w|Boris Karloff}} as The Monster, then they could be correctly said to be "containing ''Frankenstein''”—that is, the work. Because of the ambiguity regarding what Frankenstein refers to, this would not be a good CAPTCHA because many people solving it would use an incorrect definition of Frankenstein and therefore get it wrong. (However, it would be effective in screening for people who know that Frankenstein technically refers to the scientist, not the monster—or, if one also had to mark the boxes depicted Frankenstein's monster, screening for people who don't know.)

This comic strip could also reference [[1897]], which would imply that someone had actually created a Frankenstein's monster which needs to be located.

Many of the other tiles appear to be pictures of entities that inspire similar pedantry. For example, there is a picture of a turtle (or possibly a tortoise, or a reference to the Voight-Kampff test used in a manner analogous to CAPTCHA), a ship (or possibly a boat), Link (the name given to each of several protagonists that appear across generations and timelines, throughout the {{w|Legend of Zelda}} video games, who many erroneously refer to as Zelda), a pond (or possibly a lake, or a {{w|mirage}}), a squash or pumpkin (often subject to the ''fruit or vegetable'' debate), an erupting volcano (with lava, or is it magma?), and an asteroid or planet (or is it a dwarf planet?). Other tiles seem to be inspired by images that commonly occur in actual captchas, like the STOP sign or the traffic light. However, at least some of these may also be meant to fall into the category of entities that inspire pedantry, for example: because traffic lights can also be called traffic signals or stoplights; many people thinking that the shape of a stop sign is a hexagon, not an octagon; and the definition of a sandwich (previously discussed as a “random semi-ironic obsession” in [[1835]]).

The title text refers to the fact that if you draw a picture of a boat/ship on calm water (a straight line), it is usually assumed to be on a lake or pond and is thus a boat, but if it is on wavy water (as in the comic), it's assumed to be on the sea and is thus a ship{{citation needed}}. The phrase "a line drawn in water" is an idiom for something ephemeral. Ironically, it has persisted for a long time and dates back at least to the early Buddhists. (e.g. [https://suttacentral.net/an3.132/en/sujato?layout=plain&reference=none&notes=asterisk&highlight=false&script=latin| AN 3.132] & [https://suttacentral.net/an7.74/en/sujato?layout=plain&reference=none&notes=asterisk&highlight=false&script=latin| AN 7.74]). The title text is also a pun on the common idiom "drawing a line in the sand."

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

:[A captcha design, with a header and four rows of four pictures each below it. The header, in white lettering on a blue background, reads:]
:TO CONTINUE, PLEASE CLICK
:ALL SQUARES CONTAINING
:FRANKENSTEIN

:[The pictures, all with gray backgrounds, are as follows, from left to right in each row:]

Row 1
* Tortoise (or turtle)
* Ship (or boat)
* Frankenstein's monster (often mistaken as Frankenstein) waking up from a slab, while lightning strikes.
::Monster: GRRR
* Link from Legend of Zelda series (often mistaken as Zelda, aka Toon Link in SSB)

Row 2
* Lake (or pond), possibly a mirage, in the Egyptian desert
* Megan (or Science Girl, or Danish--possibly a direct joke about this wiki)
* Lava (or magma)
* Squash or pumpkin (fruit vs vegetable)

Row 3
* A mad scientist (Victor Frankenstein) throwing a switch while lightning strikes outside
::Frankenstein: It's alive!
* Sandwich
* Stop sign
* Girl running away from Frankenstein's monster
::Girl: Monster!

Row 4
* Rocket (spaceship) flying by an asteroid or Pluto (dwarf planet)
* Cueball and Ponytail standing next to each other
* Traffic light (also called a stoplight, possibly mistaken as stop sign?)
* Frankenstein's monster

:[Caption below the panel]:
:Oh no.

{{comic discussion}}
[[Category:CAPTCHA]]
[[Category:Fiction]]
[[Category:Animals]]
[[Category:Food]]

Talk:493: Actuarial

2015-06-22T01:24:38Z

108.162.216.113: c-c-c-comment

I have no time for searching right now, but I'm sure there is a graph comic related to this sentence: "2038: Last of the original Star Wars cast dies." BTW: please create only pages with an proper explanation. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:45, 6 June 2013 (UTC)

While I'm not the guy/gal who created the page, I thought I'd supply a short explanation, to be refined as necessary. BTW, the linkies at the bottom suggest that this is a "Comic with colour", but I only see monochrome. Is this a human error, or is it an automated response to the supplied image (while being black on white, or maybe greyscale) 'officially' having a colour palette or something in its header? [[Special:Contributions/178.107.63.150|178.107.63.150]] 23:35, 6 June 2013 (UTC)

His choice of year 2038 could be related to the year 2038 problem. If we assume that C3PO and R2D2 run Unix, then the year 2038 would be the end of Unix time, and they would therefore die. [[Special:Contributions/141.101.80.212|141.101.80.212]] 11:18, 14 July 2014 (UTC)

No, Randall wrote an actual Python script to calculate these. I'd give a link, but he's since removed them from the site. He made a blog post, though.[[Special:Contributions/108.162.216.113|108.162.216.113]] 01:24, 22 June 2015 (UTC)

Talk:493: Actuarial

2015-06-22T01:23:59Z

108.162.216.113:

Talk:1524: Dimensions

2015-05-15T03:20:01Z

108.162.216.113: comment

This almost seems to be making fun of the frivolity with which people discuss the existence of multiple dimensions without realizing what that actually means. Anyone else get that feeling?

Reminds me of http://xkcd.com/417/ and http://en.wikipedia.org/wiki/Patema_Inverted which make fun of dimensions too. {{unsigned ip|108.162.230.59}}
:Great - I will add 417. please sign you comment with <nowiki>--~~~~</nowiki> ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:57, 13 May 2015 (UTC)

My first thought about Title Text was that moving sideways (standard x or y axis) would be bad, but not as bad as moving upwards (standard z axis). Z direction would be my least favourite! --[[Special:Contributions/141.101.104.57|141.101.104.57]] 08:20, 13 May 2015 (UTC)

The explanation looks more and more like a discussion. Four dimensions or eleven? I see that string theory "predicts 10 or 26 dimensions" (http://en.wikipedia.org/wiki/Spacetime). I think someone (but not me) should rewrite the discussion in a more comprehensive way.[[User:Jkrstrt|Jkrstrt]] ([[User talk:Jkrstrt|talk]]) 08:35, 13 May 2015 (UTC)

We might had a link to the 2 what-if related to move steadlily in one direction : http://what-if.xkcd.com/135/ and http://what-if.xkcd.com/64/ {{unsigned ip|188.114.101.12}}

Isn't the alt text a reference to the fact that a cartoon only has two physical dimensions? That's how time can be in his top three. [[Special:Contributions/141.101.99.113|141.101.99.113]] 09:09, 13 May 2015 (UTC)

"Being pushed in one of the other directions could be lethal, if you where pushed hard enough against a rock, over a cliff or in front of a truck..."
Being pushed in the dimension of time is also ultimately fatal though. Push someone through time for long enough and they'll certainly die. [[Special:Contributions/141.101.92.8|141.101.92.8]] 09:20, 13 May 2015 (UTC)

Why the hang up on fixed coordinate systems even though there isn't even a practical way to establish one. (To the best of my knowledge distance can only be measured relative to some object.) it's more likely that the top three dimensions would be along the lines of North/South, East/West and time which is a much more practical point of view.--[[Special:Contributions/108.162.237.183|108.162.237.183]] 11:32, 13 May 2015 (UTC)

''So if it is in the top three out of four, it must be number one...''.
I don't agree. What if Randall would hate going to Zazane galaxy or Ottzello galaxy (X axis), but wouldn't mind going to Xanthrus spiral or Rizoku galazy (Y axis) [http://vignette4.wikia.nocookie.net/spore/images/6/61/INTERGALACTIC_MAP-2.png/revision/latest?cb=20100616044044]. [[Special:Contributions/108.162.238.144|108.162.238.144]] 13:50, 13 May 2015 (UTC)
:The argument would be that this is an arbitrary/anthropocentric classification of X, Y and Z that the universe neither confirms nor denies as the 'true' direction of the three dimensions (which can be in any direction, so long as each is perpendicular to the two others, in a Euclidean sense).
:(And personally. as opposed to the current description. I tend to think of x/y as the horizontal plane and z as vertical motion (up or down, depending on utility), in everyday use, although I'm flexible and will subscribe to one or other standard (and handedness of unit directions!) when dealing with other modelling systems. It's all easily convertible-between.) [[Special:Contributions/141.101.99.79|141.101.99.79]] 17:31, 13 May 2015 (UTC)

I was going to say that if we think of three dimensions simplistically as length-width-height, it might make sense for someone to have a least-favorite spatial dimension--maybe width, since we're always fighting increases in that one. But, I REALLY like the idea above that time would be in the "top three" dimensions for a TWO-dimensional comic-strip character! (Note that Randall plays with this in the Wired comic series linked above, noting that in a comic strip, a small movemement indicates movement through space, but a large one--like between panels--indicates time: see panel #15 in the series) Clever and Randall-esque idea!! I suggest adding this idea to the main text and taking out some of the other discussion around this point.[[User:Jv|Jv]] ([[User talk:Jv|talk]]) 16:32, 13 May 2015 (UTC)

Could it be that the title text is purely playing with words, as in any list of length n (4 dimensions in the world of the comic), one can only have n-1 favourites, so Cueball can only have a top / favourite 3? [[User:Mb|Mb]] ([[User talk:Mb|talk]]) 20:06, 13 May 2015 (UTC)

"Moving forward in time will also eventually be lethal by causing old age, ... But it is only possible to avoid these dangers by sidestepping them in one of the three spatial dimensions." - Wait! I can sidestep '''death'''? AWESOME! [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 20:09, 13 May 2015 (UTC)

The explanation says his favourite co-ords could still be x,y and z. Shouldn't that really by r, phi, theta since that's the best system for a spherical Earth? Also, I don't think you need to mention special relativity, even in classical physics you consider time to be the fourth dimension, you just lack a co-ordinate transformation between space and time. [[Special:Contributions/141.101.98.193|141.101.98.193]] 15:22, 13 May 2015 (UTC)

Does the statement: “pushed inexorably forward through time” not strike anyone as important to discuss and explain? A book by Dan Falk describes the ramifications were one able to move volitionally through time: http://tinyurl.com/l2btjfd.

The Greeks held that time flowed like a river through the present from the past. Others (?) suggest that time flowed from the future into the present. Randall poses that we are pushed forward through time. Who or what does the pushing? With what purpose? To what end?

Pushing suggests we’re unwilling to go forward. But so does pulling. Pulling, by the way, might imply gravitational forces at work. However, those almost never end well. [[User:Run, you clever boy|Run, you clever boy]] ([[User talk:Run, you clever boy|talk]]) 14:30, 14 May 2015 (UTC)

== time ==

I was surprised nobody mentioned Randall's most famous comic about [[Time]] (which this comic reminded me of a little bit). [[User:WhiteDragon|WhiteDragon]] ([[User talk:WhiteDragon|talk]]) 23:30, 14 May 2015 (UTC)

I love how the title text seems to imply that Randall has a least favorite space-dimension. The three space dimensions are arbitrarily assigned (they are orthogonal to each other but not absolute in relation to anything) so it's like he has a grudge against a completely arbitrary direction.[[Special:Contributions/108.162.216.113|108.162.216.113]] 03:20, 15 May 2015 (UTC)

1454: Done

2014-12-03T14:49:46Z

108.162.216.113:

{{comic
| number = 1454
| date = December 1, 2014
| title = Done
| image = done.png
| titletext = I'm sorry, but the author of this Facebook comment clearly believes you were.
}}

==Explanation==
{{incomplete|Check for grammar and improve readability of title text.}}

This comic is a joke about the rhetorical device ''shut it down'' being taken literally. If someone thinks that a device has achieved its goal they shut it down. After an idea or product that people think is well made is created people will joke that the process that created it should be shut down, as it has achieved its ultimate purpose. This rhetorical device is most often used sarcastically for an inferior product or idea. Taking things literally is a common theme in the xkcd comics.

Curly-hair sits at a computer anxiously and nervously writing a message to someone she cares about deeply (possibly a child to be adopted or a romantic intrest). Curly-hair plans on saving enough money to have the person flown to her location from "half a world away." Curly-hair ends the message with a promise to communicate daily until the two are able to meet. When attempting to send the message, however, Curly-hair discovers that their internet connection is down and the message goes unsent.

[[Ponytail]] explains there was a "ridiculous video", and someone had commented, "That's it. Shut down the Internet. We're done." This was taken literally, and because of this the internet was shut down, and Curly-hair was left unable to communicate with their love.

The joke is that what the internet was creating between Curly-hair and her love was far better than any ridiculous video. The comic highlights the beautiful and far reaching potential impact of the internet.

In the final panel Curly-hair states longingly that she was not done with the internet. The title text is Ponytail's response, which asserts Ponytail's belief that the Facebook commenter decided that Curly-hair's message wasn't important.

==Transcript==
:Writer (typing): I had started to think I was asking too much, that I needed to settle. And then I found you half a world away.

:Writer (typing): I've been saving money. Six months from now, I'll be able to fly you here and support us for a while.

:Writer (typing): It's a long wait, but we'll talk every day until then. Maybe this won't work out, but I want to try. What do you think?

:Computer: '''ERROR''': Your message could not be sent.
:''[Refresh]''
:Computer: '''ERROR''': No connection.
:Writer: ??

:Writer: Why can't I connect?
:Ponytail: Someone saw a ridiculous video and said "That's it. Shut down the Internet. We're done." So they did.

:Writer: ...But... I wasn't done.

{{comic discussion}}
[[Category:Comics featuring Ponytail]]

1454: Done

2014-12-01T05:20:04Z

108.162.216.113: /* Transcript */ initial transcript, sorry I don't know the character names

{{comic
| number = 1454
| date = December 1, 2014
| title = Done
| image = done.png
| titletext = I'm sorry, but the author of this Facebook comment clearly believes you were.
}}

==Explanation==
The comic pokes fun at an internet meme in which users will post comments like "That's it. We're done. We can shut down the internet now." in response to content found humorous or clever. The comic contrasts the legitimate, intimate impact the internet can have with the simple entertainment value that some people can see as its only or primary use.

==Transcript==
Girl 1 (typing): I had started to think I was asking too much, that I needed to settle. And then I found you half a world away.

Girl 1 (typing): I've been saving money. Six months from now, I'll be able to fly you here and support us for a while.

Girl 1 (typing): It's a long wait, but we'll talk every day until then. Maybe this won't work out, but I want to try. What do you think?

Computer: '''ERROR''': Your message could not be sent.

''[Refresh]''

Computer: '''ERROR''': No connection.

Girl 1: ??

Girl 1: Why can't I connect?

Girl 2: Someone saw a ridiculous video and said "That's it. Shut down the internet. We're done." So they did.

Girl 1: ... But... I wasn't done...

{{comic discussion}}

1454: Done

2014-12-01T05:10:52Z

108.162.216.113: Adding initial explanation - sorry it's not eloquent

{{comic
| number = 1454
| date = December 1, 2014
| title = Done
| image = done.png
| titletext = I'm sorry, but the author of this Facebook comment clearly believes you were.
}}

==Explanation==
The comic pokes fun at an internet meme in which users will post comments like "That's it. We're done. We can shut down the internet now." in response to content found humorous or clever. The comic contrasts the legitimate, intimate impact the internet can have with the simple entertainment value that some people can see as its only or primary use.

==Transcript==
{{incomplete transcript}}

{{comic discussion}}

Talk:417: The Man Who Fell Sideways

2014-12-01T03:24:11Z

108.162.216.113: Just a couple of opinions on the comic

I feel like the child should fall at a shallower angle from horizontal. There must be some way to do a punnet square for these things...
[[User:BruceJohnJennerLawso|BruceJohnJennerLawso]] ([[User talk:BruceJohnJennerLawso|talk]]) 22:47, 8 November 2013 (UTC)
: But then he/she would actually hit the ground at some point. It would make for a pretty boring sequel. [[Special:Contributions/108.162.216.113|108.162.216.113]] 03:24, 1 December 2014 (UTC)

The "when he was restrained, it grew erratic" seems to imply that gravity always pulls him horizontally to the surface he's on. Otherwise, he would be able to stand on a wall, instead of bouncing around. This is one weird kind of gravity.[[Special:Contributions/108.162.219.7|108.162.219.7]] 20:10, 26 February 2014 (UTC)

Any thoughts pertaining to Megan being the victim of rape in this strip? [[Special:Contributions/108.162.250.210|108.162.250.210]] 01:10, 28 June 2014 (UTC)
:If it was unintentional rape, does that make it ok? Answer: probably not, but maybe we should not read too much into the comic...[[Special:Contributions/108.162.254.66|108.162.254.66]] 16:24, 14 July 2014 (UTC)
::"He found, where he could, food and love" - that sounds entirely intentional. Also, considering this entire website is set up to discuss and analyse XKCD comics, saying "we should not read too much into the comic" when the subject of rape arises is pretty shocking.[[Special:Contributions/108.162.250.210|108.162.250.210]] 11:52, 2 August 2014 (UTC)

The transcript of this comic says that Cueball is under the water for three of the four "water" panels. However, based on the wave visible in the first two panels, the splashes caused by his feet in the third panel, and the lack of a wake in the fourth panel, I believe that Cueball is sliding across the water on his feet, instead of being submerged most of the time.[[User:Codefreak5|Codefreak5]] ([[User talk:Codefreak5|talk]]) 16:57, 15 July 2014 (UTC)

This sounds more like a parody of the general plot of The Time Traveler's Wife (by Audrey Niffenegger) than anything. Or perhaps the book is more like this... [[Special:Contributions/108.162.216.113|108.162.216.113]] 03:24, 1 December 2014 (UTC)