explain xkcd - User contributions [en]

3204: Dinosaurs And Non-Dinosaurs

2026-03-05T01:41:25Z

The Shard Insanity: /* Explanation */

{{comic
| number = 3204
| date = February 6, 2026
| title = Dinosaurs And Non-Dinosaurs
| image = dinosaurs_and_non_dinosaurs_2x.png
| imagesize = 370x283px
| noexpand = true
| titletext = Staplers are actually in Pseudosuchia, making them more closely related to crocodiles than to dinosaurs.
}}

==Explanation==
{{incomplete|This page was created by a CHROME DINOSAUR; however, it is definitely not. Don't remove this notice too soon.}}

This comic explores the seeming paradox that certain extinct prehistoric species which are popularly thought of as being "dinosaurs" are, from a strict {{w|taxonomy|taxonomic}} viewpoint, not. It also takes into account the fact that all {{w|bird}} species are descended from {{w|dinosaur}}s and thus - again, from a strict taxonomic viewpoint - are themselves dinosaurs as well (see [[1211: Birds and Dinosaurs]]). To illustrate this, [[Randall]] provides silhouettes of
* dinosaurs
* entities that are widely thought of as dinosaurs but are not
* entities that are ''not'' widely thought of as dinosaurs but ''are'' (i.e. birds)
* and, lastly, entities that are neither dinosaurs nor thought of as dinosaurs (which is funny because it's so all-encompassing as to be practically meaningless, just like it would be if you replaced the word "dinosaurs" by any other plural noun or adjective).

=== Creatures that seem like dinosaurs and are dinosaurs ===
* {{w|Stegosaurus}}
* {{w|Triceratops}}
* {{w|Tyrannosaurus}} Rex, whose name literally translates to ''Tyrant-Lizard King'', was a {{w|Late Cretaceous}} dinosaur, living during the {{w|Maastrichtian}} Age at the very end of the period. It was a contemporary of Triceratops and Mosasaurs, also listed in this comic. T-Rex is arguably the most well-known dinosaur, due to the recovery of intact skeletons, as well as successful marketing and pop-culture influences, such as ''{{w|Jurassic Park}}'', one of Randall's favorite films.
* {{w|Diplodocus}}
* {{w|Velociraptor}}

=== Creatures that seem like dinosaurs, but are not ===
Dinosaur is a {{w|paleontology}} term which refers to a specific group of reptiles, based upon evolutionary lines, bone structure and living domain. However, non-experts may have difficulty distinguishing these from other extinct large reptiles/creatures and apply the term somewhat indiscriminately, hence the confusion between what is scientifically included and what is culturally assumed to be included.

The creatures listed are:
* {{w|Mosasaur}}s were aquatic reptiles that existed during the Cretaceous. Although mosasaurs appeared in ''{{w|Jurassic World}}'', they are not closely related to dinosaurs. They actually evolved from lizards and are most closely related to either snakes or varanoids (such as the Komodo dragon).
* {{w|Plesiosaur}}s were another group of Mesozoic aquatic reptiles. Their place in the reptile family tree is debated, as they are not closely related to dinosaurs or any extant reptile.
* {{w|Pteranodon}} belonged to the group of flying reptiles known as pterosaurs. While dinosaurs and pterosaurs are both archosaurs and are more closely related to each other than other archosaurs (such as crocodilians; see title text explanation below), they diverged around 250 MYA, and are distinct enough to be entirely separate lineages.
* {{w|Dimetrodon}} lived in the {{w|Paleozoic}}, well before dinosaurs first evolved. They are synapsids, which makes them more closely related to {{w|mammal}}s than to any living reptiles.
* {{w|Quetzalcoatlus}} was a genus of flying pterosaurs, like ''Pteranodon'', that lived in the Maastrichtian Age (the end of the Cretaceous) alongside mosasaurs, T-Rex and many others. They were some of the largest flying animals in history, with wingspans up to 36 feet (11m). They were not, however, dinosaurs, as they had pterosaur ancestry.

=== Creatures that don't seem like dinosaurs, but are ===
Due to the popular depiction of dinosaurs as prehistoric large reptiles, many people don't view modern birds as dinosaurs. However, as Randall [[1211: Birds and Dinosaurs|loves to remind people]], dinosaurs such as ''T-rex'' are more closely related (temporally, anatomically and phylogenetically) to birds than to some other dinosaurs such as ''Stegosaurus'', and therefore, birds '''are''' dinosaurs in their own right.
* {{w|Penguin}}
* {{w|Heron}}
* {{w|Ostrich}}
* {{w|Pigeon}}
* {{w|Falcon}} or {{w|Petrel}} (both of them qualify)

=== Creatures that don't seem like dinosaurs, and are not ===
* {{w|Squirrel}}: Squirrels are mammals, and dinosaurs are reptiles. Most people also think of dinosaurs as large and dangerous, while squirrels tend to be small, cute and relatively harmless (although their bites can transmit infection). Could also be made of [[2186: Dark Matter|dark matter]].
* {{w|Stapler}}: Staplers are inanimate objects, and dinosaurs are living creatures.
* {{w|Flowerpot|Potted plant}} or {{w|pineapple}}: Dinosaurs are animals, and plants are not.
* {{w|Human}} ([[Cueball]]): Humans are mammals, and dinosaurs are reptiles. In fact, the {{w|Jurassic Park (franchise)|''Jurassic Park''}} series often pits the two against each other.
* {{w|Bicycle}}: While they tend to be more mobile than staplers, and have {{w|Dandy horse|some relation}} to horses, bicycles are also not living creatures.

The title text is a further joke about taxonomy, seemingly predicated on the assumption that staplers are biological organisms (which they are not),{{Citation needed}} and can thus be sorted into taxa. ''{{w|Pseudosuchia}}'' is in fact the clade of archosaurs that includes crocodilians, and staplers bear a certain resemblance to the open mouth of a crocodilian. Also, "suchia" sounds a little like "suture," and in some sense staples are pseudo {{w|Surgical suture|sutures}}.

The original {{w|Linnaean taxonomy}} ''did'' at first have a top-level classification for "mineral" taxonomy, in addition to those for animal and plant, which {{w|Twenty questions#Popular variants|in its broadest sense}} might allow one to assign a stapler a taxonomic relationship with dinosaurs.

==Transcript==
:[A 2x2 chart where each of the four quadrants contains five silhouettes. These depict various animals, a few objects, and a human. Above each column and to the left of each row there are a label:]
:[Left column:] Are dinosaurs
:[Right column:] Are not dinosaurs
:[Upper row:] Seem like dinosaurs
:[Lower row:] Don't seem like dinosaurs

:[Here follows a list of what are in each of the four quadrants:]

:[Top left (seem like dinosaurs, are dinosaurs):]
:[Stegosaurus, triceratops, tyrannosaurus, diplodocus, and velociraptor.]

:[Top right (seem like dinosaurs, are not dinosaurs):]
:[Mosasaur, quetzalcoatlus, dimetrodon, plesiosaur, and pteranodon.]

:[Bottom left (don't seem like dinosaurs, are dinosaurs):]
:[Penguin, egret, falcon, pigeon, and ostrich.]

:[Bottom right (don't seem like dinosaurs, are not dinosaurs):]
:[Squirrel, stapler, bicycle, human (here depicted as Cueball), and potted plant.]

{{comic discussion}}<noinclude>
[[Category:Confusion matrices]]
[[Category:Biology]]
[[Category:Dinosaurs]]
[[Category:Velociraptors]]
[[Category:Squirrels]]
[[Category:Animals]]
[[Category:Comics featuring Cueball]]

2537: Painbow Award

2026-03-05T01:39:59Z

The Shard Insanity: /* Explanation */

{{comic
| number = 2537
| date = November 3, 2021
| title = Painbow Award
| image = painbow_award.png
| titletext = This year, our team took home the dark blue ribbon, better than the midnight blue we got last year but still short of the winning navy blue.
}}

==Explanation==
[[File:WeatherBow.png|500px|thumb|left|An example of a color scaled weather report.]]

This comic makes fun of the badly selected color scales used in the figures for scientific papers by suggesting that the scientists picking them are in competition to use the most problematic scale. The title of the comic is a portmanteau of "pain" and "rainbow" suggesting a humorous name for terrible color scales.

The color scale here showcases a collection of unintuitive and unhelpful decisions. Starting from the top, white fades down into green, which then fades into red (passing through brown in the middle instead of yellow, indicating {{w|subtractive color}} mixing instead of {{w|additive color}} mixing, for no obvious reason). The red then turns ''back'' into green as the intensity decreases further. Red and green in close proximity make the energy levels hard or impossible to distinguish for those with {{w|Color_vision_deficiency#Protanopia|protanopic color vision deficiency}}. This confusion is repeated at lower energy levels, where blue transitions to black and then back into white via a gray with a tiny tinge of blue. The highest and lowest recorded energy levels have the same color value, which is less than ideal. That [[Randall]] is aware of color blindness and the problems this causes has been revealed in other comics like this one [[1213: Combination Vision Test]].

Although it's possible (for someone with full color vision) to interpret data from this graph from context clues - the white that fades to green is high-energy white, while the white that fades to blue is low-energy white - there's no benefit to doing things this way, and a lot of downsides. Additionally, there are regions in the color scale where the color changes very rapidly, which creates the false appearance of an edge in what is likely a smooth function.

Real-world analogues to the Painbow Award include radar meteorology charts, where different types of precipitation have different color schemes that can overlap and blend in confusing transition zones. In the field of data visualization, the {{w|CIELAB color space}}, [https://bids.github.io/colormap/ perceptually uniform color spaces], or even more [https://ai.googleblog.com/2019/08/turbo-improved-rainbow-colormap-for.html specialized] [http://www.kennethmoreland.com/color-maps/ scales] have been developed to replace simple algebraic interpolation of red, green, and blue values.

The title text takes the concept of bad color combinations further, suggesting the use of navy blue (    ), dark blue (    ), and midnight blue (    ) for first, second, and third respectively. These are the names of three similar {{xkcd|color/rgb|xkcd colors}}, and, as [[315: Braille|sighted readers]] will be able to see, there is very little difference between them. However, the choice of blue(s) may be a direct play upon the association of the {{w|Blue Riband}} (a.k.a. "Blue Ribbon") and/or {{w|Le Cordon Bleu|Cordon Bleu}} (likewise, but this time direct from the French) awards, extended in common use for excellence across a much wider range of competitive fields.

For rosette-rewarded competitions (e.g. livestock parades, dog-shows, etc) the {{w|Blue ribbon|first prize ones are commonly blue}} (red for 2nd and either yellow or white for 3rd), though it may not be logically obvious to someone unfamiliar with this, perhaps more used to yellow depicting the 'gold standard, first place' indicator or red as the most alerting hue in some other ranking situations. Where a depicted award schema ''is'' directly gold/silver/bronze-influenced, however, the gold and bronze 'metallic off-yellows' can sometimes be more confused with each other than with the mid-level desaturated 'silver'

==Transcript==
:[A figure of a graph is shown, the figure has a number as if used in a paper. The graph has two labeled axis, however they have no units. The Y-Axis has 15 ticks of equal length, the X-axis has 21 ticks, with every fifth double the height of the other. The graph displays a messy shape with color gradients, with a bright spot to the right of the shape around the middle right part of the graph. This bright spot is surrounded by mainly green and red, with darker colors at the edge, and the rest of the graph white. On the right side of the graph there is a labeled bar with the color scale. To the right of this are numbers indicating what the color represents. The color scale begins at the bottom with white, then goes to gray/blue, to black, back to blue, to gray, to green, to dark red, to red which fades via brown in to green, from where it fades slowly from darker green to lighter green ending up as yellow before going back to white again at the top.]
:Label: Figure 2
:Y-Axis: λ
:X-Axis: θ (phase)
:Scale label: Peak Energy
:120 (White)
:100 (Green)
:80 (Darker green)
:60 (Red)
:40 (Green)
:20 (Black)
:0 (White)

:[Caption under the panel:]
:Every year, disgruntled scientists compete for the Painbow Award for worst color scale.

==Trivia==
*When [https://www.explainxkcd.com/wiki/images/archive/e/ef/20211103203044%21painbow_award.png originally uploaded], the caption used the phrase "color gradient" rather than "color scale"

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Charts]]