explain xkcd - User contributions [en]

Talk:2783: Ruling Out

2023-05-31T20:52:49Z

172.71.166.249:

Wow. the amount of citation needed tags is excessive. Here's a fun idea, do like that SMBC comic and actually find and give citations. [[Special:Contributions/172.69.70.72|172.69.70.72]] 19:41, 31 May 2023 (UTC)Bumpf
:Definitely. I fixed one (it should have been ''after'' the comma), during some other edits, but was sorely tempted to remove maybe two of them to just keep the funniest one(s). Whichever that(/they) might be. I expect they'll almost all evaporate in a future edit, though, as there's plenty of editting bound to be done. [[Special:Contributions/172.70.90.219|172.70.90.219]] 19:47, 31 May 2023 (UTC)

I'm pretty sure there has been serious scholarship about the habitable zone of some quasars. Let's see.... Here: https://iopscience.iop.org/article/10.1088/1742-6596/2364/1/012057/pdf Not absolutely certain, but absolutely '''not''' ruled out. [[Special:Contributions/172.69.134.24|172.69.134.24]] 20:02, 31 May 2023 (UTC)

:I think that Cueball's scientific team did a study to discount the possibilities of quasars in the habitable zone of a star, not of a habitable zone around a quasar.[[Special:Contributions/172.71.166.249|172.71.166.249]] 20:52, 31 May 2023 (UTC)

2754: Relative Terms

2023-04-29T23:17:28Z

172.71.166.249: It is literally in the name, was this original description written by an AI?

{{comic
| number = 2754
| date = March 24, 2023
| title = Relative Terms
| image = relative_terms_2x.png
| imagesize = 425x442px
| noexpand = true
| titletext = Small sewing machines are sewing machines that are smaller than a sewing machine. A sewing machine is larger than a small sewing machine, but quieter than a loud sewing machine.
}}

==Explanation==
The terms "small" and "big" are used to refer to size; the terms "loud" and "quiet" are used to refer to (audial) volume. While these terms are relative, they are often used even when there is nothing obvious being compared against (e.g. "A windmill is a big thing" or "An ant is a small thing").

This comic humorously suggests that the item defined to be in the middle of all four terms ("neither small nor big; neither quiet nor loud") is a sewing machine, as a sewing machine seems (at least in comparison to the other items on the graph) to be neither particularly big nor particularly small; neither particularly quiet nor particularly loud. A standard sewing machine is roughly 60dB in volume and approximately 42” X 21”, although this is for industrial machines, and those in the home (table-top electric models) would be both smaller and quieter. More antique treadle-powered sewing machines might include the treadle-table, as an integral part of its size, but could be even quieter if kept well-maintained.

As the reference point, the sewing machine is placed in the center of the chart, while a selection of other example objects are located in the four quadrants around it, based on whether they are considered to be small or big, and loud or quiet. Many of the items might appear to have been placed in the wrong quadrant for their actual attributes; locations may reflect more how Randall generally thinks of these things, as opposed to others' subjective ideas of their real-life relationship to a sewing machine.

Other references from everyday life that could be placed in the center include the average adult human (the perspective from which people might measure other things), a bread-bin/box (a popular comparison for size {{w|breadbox#As a saying|in certain situations}}, but doesn't fit the bill in terms of loudness), or even something like "the size of a large/small/medium-sized dog" (which highly depends upon a shared reference of which breeds are commonly encountered, and dogs might be considered too loud to be in the middle of the volume range), all things that are often encountered. A sewing machine may once have been found in many homes, but some of the comic's comedic value may arise from the relative rarity in modern times.

The title text is humorously tautological because it compares the standard against those things that are themselves defined against the standard.

{| class="wikitable"
|+ Small and quiet (upper left)
|-
! Item !! Description
|-
| Ant || Randall has used ants as a small comparator in [[2733:_Size_Comparisons|a previous comic]] on the topic of comparisons.
|-
| Balloon || A party balloon is quite loud when it pops, or if someone 'squeaks' it by rubbing; a hot-air balloon is big enough to carry a few humans, and the burner can be surprisingly loud.
|-
| Book || Books are typically sized to be handheld, and thus smaller than a sewing machine, though some very large books do exist.[https://www.smithsonianmag.com/smart-news/longest-book-in-the-world-impossible-to-read-180980814/#:~:text=At%2021%2C450%20Pages%2C%20the%20Longest,World%20Is%20Impossible%20to%20Read&text=Artist%20Ilan%20Manouach%20bound%20together,the%20commodification%20of%20comic%20books.] Similarly, books are associated with quiet activity, making no more sound than a quiet turning of a page in typical use, but could make a very loud bang if slammed shut on thrown forcefully on to a hard surface.
|-
| Bun (rabbit or pastry) || "Bun" is an informal term for a rabbit and a loaf of bread; a comparison between the two was made in [[1871: Bun Alert]]. While {{w|Flemish_Giant_rabbit|some rabbits}} may reach the size of a small dog or a child, and specially baked items for promotional activity or record attempts may exceed the size of a sewing machine, both would typically be smaller. However, while bread, even when being eaten, is usually very quiet, rabbits can make a large amount of noise that is at odds with their common image.
|-
| Butterfly || Butterflies are used as an exemplar of something small, unnoticeable and seemingly insignificant in the metaphor of the Butterfly Effect.
|-
| Hat || A hat, being a non-living item of clothing, is very quiet. They also come in a range of sizes, hence their position in the middle of the Big/Small axis.
|-
| Mouse || A mouse is a very small, quiet animal. This might also be a reference to the expression "quiet as a mouse", meaning very quietly.
|-
| Newt || A newt is a semi-aquatic salamander. Being fairly small and living in water most of the time, they are very quiet.
|-
| Pin drop || The expression "hear a pin drop" is used to indicate that an area is exceptionally quiet; the idea is that the space is so silent that even something as insubstantial and tiny as a pin can be heard hitting the ground.
|-
| Snow globe || A {{w|snow globe}} is much smaller than a sewing machine. Some snow globes have a small music box that can be wound up to play a melody. Snow globes without a music box are silent.
|}

{| class="wikitable"
|+ Small and loud (upper right)
|-
! Item !! Description
|-
| Baby || Babies are usually considered small, and can be quite loud when they cry.
|-
| Blender || Blenders make a lot of noise when in use. Most household blenders are smaller than a sewing machine.
|-
| Cricket || Given that it is in the small/loud quadrant, this would refer to the insect, which is pretty small and can be quite loud; the sport of cricket or a cricket game would be much larger (though potentially much louder).
|-
| Fire alarm || The primary purpose of a fire alarm is to notify people of fire, so fire alarms are usually very loud, but ideally take up little space.
|-
| Firecracker || A {{w|Firecracker}} is a small explosive firework that makes a very loud bang when lit.
|-
| Flute || An example of a small musical instrument that can nevertheless be audibly quite dominant.
|-
| Harmonica || See Flute.
|-
| Popcorn || A snack that, as the name implies, is known for a popping sound when cooked, owing to moisture inside the kernels being heated and creating pressure. May also be annoyingly loud in a cinema setting. However, this is largely due to the otherwise low volume environment, and arguably a sewing machine might be equally or more annoying. Individual kernels, popped or unpopped, are generally smaller than a sewing machine{{fact}}. Actual servings of popcorn in some cinemas may however be larger than a sewing machine.
|-
| Songbird || {{w|Songbirds}}, despite being very small, are well known for their songs that can be heard over a large area.
|-
| Whistle || This is of course a device known as a whistle, as these are small. The human act of whistling, or a whistle produced by, for example, a kettle, has no size (other than that of the whistler or whistling object). A whistle is used as an alert or signal, or could be another musical instrument (see Flute). The loudest human whistle ever recorded was 8372 Hz and roughly 110 DB, which is a C9 in the standard musical scale and is roughly as loud as a jackhammer[https://www.vnews.com/West-Lebanon-man-sets-a-world-record-for-whistling-24480844#:~:text=Guinness'%20website%20says%20Stanford%20reached,in%20the%20standard%20musical%20notation.]. Since a whistle should be able to beat this it must be seen as loud.
|}

{| class="wikitable"
|+ Big and quiet (lower left)
|-
|-
! Item !! Description
|-
| Anaconda || Snakes typically aren’t that loud, especially constrictors like anacondas.
|-
| Giraffe || Giraffes can be quite loud, but they usually vocalise using frequencies well below the range of human hearing. So, to a human, giraffes are quiet.
|-
| Northern lights || "In 2016, a Finnish study confirmed that the Aurora Borealis does produce a sound that can be heard" [https://www.techexplorist.com/listen-sound-aurora-borealis/47421/]
|-
| Shark || When people think of sharks, they typically envisage something large and dangerous, yet eerily silent as they swim (up until entering a feeding frenzy), like a {{w|Great_white_shark|great white}}. However, sharks come in a large variety of sizes, often {{w|Dwarf_lanternshark|considerably smaller}} than a sewing machine.
|-
| Statue || A stereotypical statue is a large piece of public art, intended to be viewed from afar, which would be larger than a sewing machine – even discounting the plinth or {{w|Statue of Abraham Lincoln (Lincoln Memorial)|other}} {{w|Nelson's Column|bases}}; however, there is no easily agreed lower size limit for when a statue becomes a statuette, figurine, bust or merely a carved/cast ornament, as any smaller examples of figurative art could be considered statues in a given situation. Famous and major examples do tend to be life-sized (or larger-than-life-sized) depictions of people, sometimes even depicted atop horses, making them significantly larger; even fractional-scale depictions could be easily of greater size than this comic's reference item.
Most statues are silent, but some may be plumbed in as fountains. Or occasionally equipped with other devices that make sound. There is also "musical statues" being a {{w|party game}}, that can be intermittently loud and quite large.
|-
| The Moon || The Moon is very, very big{{fact}}, but it is also completely silent{{fact}} from the perspective of most humans, since sound cannot travel through the vacuum of space.
|-
| Tree || A tree can be small and big, but generally aren't noisy outside the rustling of leaves and like. This might be a reference to the philosophical question "If a tree falls in a forest and no one is around to hear it, does it make a sound?". According to Randall, a tree falling like this would be fairly quiet.
|-
| Windmill || Windmills need to have significant height in order to catch enough air movement to drive them. They are thought of as quiet, relative to other forms of power generation; in reality, though, the passage of the blades through the air can cause considerable noise, as can [https://www.youtube.com/watch?v=dzwqBgWKalI the machinery that they drive].
|}

{| class="wikitable"
|+ Big and loud (lower right)
|-
! Item !! Description
|-
| Airplane || An airplane produces a loud sound from its engines, while also being between 40 and 50 meters in length.
|-
| Cannon || A cannon produces a loud sound when fired, and is on average 2.5 meters in length.
|-
| Riding mower || Riding mowers are big in order to accommodate a person, and are known for being very loud, with a loudness of 85-90 decibels on average.
|-
| [[wikipedia:Calliope_(music)|Steam calliope]] || A large musical device which functions by sending steam (or more recently compressed air) through attached whistles.
|-
| Train || A form of public or cargo transport with carriages, variable size and noise production.
|-
| Tuba || A musical brass instrument that creates a musical note by air blown through its mouthpiece.
|-
| Volcano || Lower right corner. Volcanic eruptions can be extremely loud. The {{w|1883 eruption of Krakatoa}} made a pressure wave of 180 dB, the loudest sound ever recorded.
|-
| Waterfall || A waterfall makes noise as it crashes over rocks. However, the sound of a waterfall is a relaxing sound to many.
|-
| Whale || Whales are the largest mammals currently living on earth, and are extremely loud in their underwater 'songs' and vocalisations, often reaching over 140 decibels. However, the frequency of these sounds is well outside the range of human hearing, which is why they're placed close to the center on the Quiet/Loud axis.
|}

==Transcript==
:[A chart, with "Quiet" to "Loud" on the X-axis, and "Small" to "Big" on the Y-axis. It is split into four quarters, with "Sewing machine" in the center.]

:[Upper left quadrant (Small & Quiet items):] Butterfly, Pin drop, Mouse, Ant, Bun (rabbit or pastry), Snow globe, Newt, Balloon, Book, Hat

:[Upper right quadrant (Small & Loud items):] Popcorn, Cricket, Songbird, Whistle, Baby, Harmonica, Flute, Fire alarm, Blender, Firecracker

:[Lower left quadrant (Big & Quiet items):] Shark, Tree, Anaconda, Giraffe, Statue, Windmill, Northern lights, The Moon

:[Lower right quadrant (Big & Loud items):] Tuba, Riding mower, Cannon, Airplane, Train, Waterfall, Steam calliope, Whale, Volcano

:[Caption below the panel:]
:''Big'', ''Small'', ''Loud'', and ''Quiet'' are relative terms. The thing they're relative to is a sewing machine.

{{comic discussion}}

[[Category:Charts]]
[[Category:Aviation]]
[[Category:Animals]]
[[Category:Buns]]
[[Category:Sharks]]
[[Category:Music]]
[[Category:Volcanoes]]
[[Category:Food]]

2749: Lymphocytes

2023-03-15T01:31:56Z

172.71.166.249: /* Explanation */

{{comic
| number = 2749
| date = March 13, 2023
| title = Lymphocytes
| image = lymphocytes_2x.png
| imagesize = 651x733px
| noexpand = true
| titletext = It's very hard to detect, but recent studies have determined that when plasma B cells are producing antibodies, they go 'pew pew pew'
}}

==Explanation==
{{incomplete|Created by the WORLD'S SECOND COOLEST IMMUNOLOGIST - Table is cool, but some entries miss mention or explanation of the text in the comic, when it may have relation to the real life cell etc. (Perhaps ensure each description covers the real description for the name and then the explanation for the rogue text. Except for the D Cell, obviously, where it is both at once.) Do NOT delete this tag too soon.}}

The human body contains many different types of immune cells. This comic is a list of {{w|lymphocyte}}s, a specific type of immune cell that is found in blood and lymph. As the comic goes on, in the style of many "informative" xkcd comics, the descriptions of the names of the cells get more and more removed from reality. Though many of the cells are real, only two descriptions are accurate, those for the plasma B cell and that of the out of context D cell. The diagrams are either uninformingly similar to each other, as an extremely generic diagram of a biological cell, or made to look somewhat like the item spoofed by the description.

The title text is possibly a reference to this recent study: https://pubs.acs.org/doi/10.1021/acsnano.3c00638

{| class="wikitable"
! Name !! Real Lymphocyte? !! Randall's description !! Comment
|-
| Plasma B cells || Yes || Churn out antibodies || {{w|Plasma B cell}}; churns out antibodies as the comic says.
|-
| Naïve B cells || Yes || Try to stop pathogens by asking nicely || {{w|B cell}}s that have not yet been exposed to an antigen. Can only "ask nicely" for pathogens to stop because they cannot yet contribute to the immune system.
|-
| {{w|Memory B cell}}s || Yes || Very quietly sing {{w|Memory_(Cats_song)|"Memory" from ''Cats''}} at all times || Long-lived B cells that "remember" an antigen they have previously encountered, allowing them to quickly respond to a reappearance of the same antigen. "Memory" is one of the most famous songs from the 1981 Andrew Lloyd Webber ''{{w|Cats (musical)|Cats}}'' musical.
|-
| {{w|Regulatory B cell}}s || Yes || Required by local ordinance || Suppress certain immune responses, or in other words, regulates the immune response, which is their actual namesake, as opposed to the made-up namesake of only being in the body because some regulation requires it. Though cells do follow instructions from DNA, which might be considered to be local ordinances.
|-
| CD8+ T cells || Yes || Melee combat || {{w|Cytotoxic T cell}}, responsible for killing cells which are cancerous or infected. Named after the surface protein "CD8" ("Cluster of Differentiation") it uses when searching for targets. Possibly also reference to the tabletop gaming terminology where "d8" means 8-sided dice, "d4" means 4-sided dice, etc. D&D and many of its derivatives use d8s primarily for damage, particularly for some of the most common weapons like rapiers, longswords, and longbows, and also for several spells like Chill Touch or Ray of Frost.
|-
| CD4+ T cells || Yes || Scream at other cells || {{w|T helper cell}}, releasing cytokines as a signal that prompts the immune system into action, thus "screaming" at other cells. Named after the surface protein "CD4" (see above), that is used for binding to other cells while "screaming".
|-
| {{w|Gamma delta T cell|Gamma-Delta T cell}}s || Yes || Unknown / classified || T cells found largely in mucous membranes of the gut, with different T-cell receptors than normal. Effectively the immune system's first line of defense.
|-
| CDRW+ T cells || No || Rewritable, 700MB || Here, the meaning of "CD" is switched from {{w|Cluster of Differentiation}} to {{w|Compact Disc}}, as in the {{w|CD-RW}} re-writable media format. 700 megabytes is a common size format for CDs.
|-
| DVD+R T cells || No || Different from DVD-R, though no one is sure how || {{w|DVD+R}} is a DVD format designed by {{w|HP Labs}}, while DVD-R (pronounced "dash R") came originally from {{w|Pioneer Corporation}} and was the earlier accepted system. The two formats are not trivially compatible, but many (re)writing DVD drives were made multiformat to automatically handle both of these, {{w|DVD-RAM}}, read/write versions and CD-density media, as necessary, under the general label of "DVD±RW". The user then ends up not usually needing, or bothering, to know the technical differences.
|-
| {{w|Natural killer cell}}s || Yes || Named by the world's coolest immunologist || Kills cells infected by intracellular pathogens and other malfunctioning (e.g. cancerous) cells, similar to CD8+ cells but part of the {{w|innate immune system}}. Randall likes the name of these cells more than the next item, making Rolf Kiessling and Hugh Pross "the world's coolest immunologist(s)."
|-
| ILC1, ILC2, and ILC3 cells || Yes || Named by a significantly less cool immunologist || {{w|Innate lymphoid cell}}s, regulating the innate immune system through signaling molecules. Named in [[https://www.nature.com/articles/nri3365 this paper in Nature]] by Hergen Spits, David Artis, Marco Colonna, Andreas Diefenbach, James P. Di Santo, Gerard Eberl, Shigeo Koyasu, Richard M. Locksley, Andrew N. J. McKenzie, Reina E. Mebius, Fiona Powrie and Eric Vivier, making them collectively much less cool than Kiessling and Pross above.
|-
| D cells || No || Larger than C and AA cells, used in old flashlights || This is not a blood cell, but a {{w|D battery|"D cell" battery}}. Confusingly, biological cells called "D cells" or {{w|delta cell}}s do exist, but they are not lymphocytes.
|}

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

[A 4 by 3 grid, each containing (from top to bottom) the name of the lymphocyte, a depiction of the cell and a description]
{| class="wikitable"
! Panel !! Title !! Shape !! Description
|-
|1 || Plasma B cells || Egg-like shaped cell with the nucleus right from the middle || Churn out antibodies
|-
|2 || Naïve B cells || Almost circular cell with the nucleus in the middle || Try to stop pathogens by asking nicely
|-
|3 || Memory B cells || Like panel 2, but with some music notes next to it, as if it produces sound || Very quietly sing "memory" from Cats at all times
|-
|4 || Regulatory B cells || Like panel 2 || Required by local ordinance
|-
|5 || CD8+ T cells || Also oblong, but with the nucleus left from the middle || Melee combat
|-
|6 || CD4+ T cells || Circular, with a large nucleus, saying ‘AAAAAAAAA!’ || Scream at other cells
|-
|7 || Gamma-Delta T cells || Dashed circle with a question mark in the middle || Unknown / classified
|-
|8 || CDRW+ T cells || Shaped like a CD, with a large hole in the middle || Rewritable, 700MB
|-
|9 || DVD+R T cells || Shaped like a DVD, with a bit smaller hole in the middle || Different from DVD-R, though no one is sure how
|-
|10 || Natural killer cells || Irregularly shaped oblong cell with nucleus in the middle || Named by the world's coolest immunologist
|-
|11 || ILC1, ILC2, and ILC3 cells || Three cells || Named by a significantly less cool immunologist
|-
|12 || D cells || Cylindrical shaped ‘cell’, with a smaller cylindrical ‘nucleus’ inside it at the right, roughly shaped like a D battery || Larger than C and AA cells, used in old flashlights
|}

{{comic discussion}}

[[Category:Biology]]
[[Category:Science]]