explain xkcd - User contributions [en]

3120: Geologic Periods

2025-07-27T15:10:08Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Explanation */ italicized taxonomic scientific names

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|''{{w|Tanystropheus}}'' was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of ''Dracaena'' dragonblood trees
|Zanclean flood
|''{{w|Dracaena draco}}'' and ''{{w|Dracaena cinnabari}}'' trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A table with 3 columns, labelled: "Period", "My favorite part" and "My biggest complaint". There are 13 rows below the labels]
:[Row 1: Period:] ''Precambrian'' [My favorite part:] Life develops [My biggest complaint:] Snowball Earth episodes
:[Row 2: Period:] Cambrian [My favorite part:] Trilobites! [My biggest complaint:] Evolution could stand to calm down a little
:[Row 3: Period:] Ordovician [My favorite part:] Earth might have had rings [My biggest complaint:] Scary volcanic eruption in North America
:[Row 4: Period:] Silurian [My favorite part:] First land animals [My biggest complaint:] Earth's newfound mold problem
:[Row 5: Period:] Devonian [My favorite part:] Big mountains in Boston [My biggest complaint:] Yeah, sure, what those giant killer fish needed was '''''armor'''''
:[Row 6: Period:] Carboniferous [My favorite part:] Cool forests [My biggest complaint:] Bugs too big
:[Row 7: Period:] Permian [My favorite part:] Pangea [My biggest complaint:] Google "The Great Dying"
:[Row 8: Period:] Triassic [My favorite part:] Tanystropheus [accompanying the text in this cell is an image of a ''Tanystropheus'' and its characteristic elongated neck, with Cueball standing next to it for scale] [My biggest complaint:] Damage to Canada still visible from space at Manicouagan
:[Row 9: Period:] Jurassic [My favorite part:] Birds [My biggest complaint:] Parasitoid wasps
:[Row 10: Period:] Cretaceous [My favorite part:] Raptors [My biggest complaint:] Raptors
:[Row 11: Period:] Paleogene [My favorite part:] Pretty horseys!!! [My biggest complaint:] Paleocene-eocene thermal maximum
:[Row 12: Period:] Neogene [My favorite part:] Forests of ''Dracaena'' dragonblood trees [My biggest complaint:] Zanclean flood
:[Row 13: Period:] Quaternary [My favorite part:] Burrito invented [My biggest complaint:] Whoever picked the name for the third period of the Cenozoic

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]

3120: Geologic Periods

2025-07-27T15:06:19Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|{{w|Tanystropheus}} was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of Dracaena dragonblood trees
|Zanclean flood
|{{w|Dracaena draco}} and {{w|Dracaena cinnabari}} trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A table with 3 columns, labelled: "Period", "My favorite part" and "My biggest complaint". There are 13 rows below the labels]
:[Row 1: Period:] ''Precambrian'' [My favorite part:] Life develops [My biggest complaint:] Snowball Earth episodes
:[Row 2: Period:] Cambrian [My favorite part:] Trilobites! [My biggest complaint:] Evolution could stand to calm down a little
:[Row 3: Period:] Ordovician [My favorite part:] Earth might have had rings [My biggest complaint:] Scary volcanic eruption in North America
:[Row 4: Period:] Silurian [My favorite part:] First land animals [My biggest complaint:] Earth's newfound mold problem
:[Row 5: Period:] Devonian [My favorite part:] Big mountains in Boston [My biggest complaint:] Yeah, sure, what those giant killer fish needed was '''''armor'''''
:[Row 6: Period:] Carboniferous [My favorite part:] Cool forests [My biggest complaint:] Bugs too big
:[Row 7: Period:] Permian [My favorite part:] Pangea [My biggest complaint:] Google "The Great Dying"
:[Row 8: Period:] Triassic [My favorite part:] Tanystropheus [accompanying the text in this cell is an image of a ''Tanystropheus'' and its characteristic elongated neck, with Cueball standing next to it for scale] [My biggest complaint:] Damage to Canada still visible from space at Manicouagan
:[Row 9: Period:] Jurassic [My favorite part:] Birds [My biggest complaint:] Parasitoid wasps
:[Row 10: Period:] Cretaceous [My favorite part:] Raptors [My biggest complaint:] Raptors
:[Row 11: Period:] Paleogene [My favorite part:] Pretty horseys!!! [My biggest complaint:] Paleocene-eocene thermal maximum
:[Row 12: Period:] Neogene [My favorite part:] Forests of ''Dracaena'' dragonblood trees [My biggest complaint:] Zanclean flood
:[Row 13: Period:] Quaternary [My favorite part:] Burrito invented [My biggest complaint:] Whoever picked the name for the third period of the Cenozoic

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]

3001: Temperature Scales

2025-07-27T15:05:34Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */ put the labels in quotation marks

{{comic
| number = 3001
| date = October 21, 2024
| title = Temperature Scales
| image = temperature_scales_2x.png
| imagesize = 740x535px
| noexpand = true
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.
}}

==Explanation==

Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same gradations as degrees Celsius but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.

The comic compares these scales, and a number of others, on [[Randall]]'s scale of "cursedness." The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. [[1643: Degrees]] provides helpful tips for choosing whether to use Celsius or Fahrenheit. See also [[1923: Felsius]].

{| class=wikitable
! scope="col" | Unit
! scope="col" | Water freezes
! scope="col" | Water boils
! scope="col" | Notes
! scope="col" | Cursedness
! scope="col" | Explanation
|-
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as "centigrade", was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given "cursedness," it is regarded as one of the least problematic temperature scales.
|-
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius do, but shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)
<center>Celsius = kelvin – 273.15</center>
<center>kelvin = Celsius + 273.15</center>
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.
|-
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 (amount of ''degrees'' in a circle) were favored in science over powers of 10, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose to base 0° on the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.
<center>Celsius = (Fahrenheit – 32) × 5/9</center>
<center>Fahrenheit = Celsius × 9/5 + 32</center>
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, and - as Randall notes - some retroactive justification coined that claims 0°F to 100°F as covering the entire range of temperatures humans would encounter in daily life. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in the U.S., its territories, the Bahamas, Belize, the Cayman Islands, Liberia and Palau.
|-
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.
<center>Celsius = Réaumur / 0.8</center>
<center>Réaumur = Celsius × 0.8</center>
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in the Celsius scale; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.
|-
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.
<center>Celsius = (Rømer – 7.5) × 40/21</center>
<center>Rømer = Celsius × 21/40 + 7.5</center>
The Rømer scale is considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.
|-
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic''; should be 0°Ra] set to absolute zero || 6/10 || The Rankine scale (°R or °Ra), created by {{w|William Rankine}} in 1859, is to Fahrenheit what the Kelvin scale is to Celsius: an absolute temperature scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.
<center>Celsius = (Rankine – 491.67) × 5/9</center>
<center>Rankine = (Celsius + 273.15) × 9/5</center>
<center>Rankine = Fahrenheit + 459.67</center>
[[2292: Thermometer]] expresses disdain for this scale.
|-
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like "the hottest water you can hold your hand in" || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the °N symbol. Unfortunately, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. [https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales His scale] used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, and 34ºN, rapidly boiling water. Therefore:
<center>Celsius = 37 × Newton / 12 if Newton ≤ 12; 63 × (Newton – 12) / 22 + 37 if Newton > 12</center>
<center>Newton = 12 × Celsius / 37 if Celsius ≤ 37; 22 × (Celsius – 37) / 63 + 12 if Celsius > 37</center>
Very few other than Newton ever used this scale, but it [https://www.scienceandsociety.co.uk/results.asp?image=10413117&wwwflag=&imagepos=43 did appear] on commercial thermometers around 1758. The cursedness rating (7-ish/10) jokes about the vagueness of the scale's definition.
|-
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.
<center>Celsius = (Wedgwood + 8) × 100/1.3</center>
<center>Wedgwood = (Celsius × 1.3/100) – 8</center>
The comic has a typo, as the scale is actually called Wedgwood, without the second 'e', but is spelled in the comic as "Wedgewood".
|-
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is "normal"(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a "neutral" temperature [https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml around 180 AD] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:
<center>Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0; 78 × Galen / 4 + 22 if Galen > 0</center>
<center>Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22; 4 × (Celsius – 22) / 78 if Celsius > 22</center>
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.
|-
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×1032K, the [https://doi.org/10.4236/jamp.2024.1210198 maximum attainable physical temperature], will be negative on this scale. The cursedness rating (10/0) is a joke on the scale "flipping" the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.
<center>Celsius = 100 – ''Real'' Celsius</center>
<center>''Real'' Celsius = 100 – Celsius</center>
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.
|-
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match the Celsius scale at 0 and 100:
<center>Celsius = 273.15 × ''e''(Dalton / 320.55) – 273.15</center>
<center>Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )</center>
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differ from Celsius ones by as much as 3.9 degrees between 0 and 100, but diverge much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.
|-
| °X || 42.9 || 151.4 || '''Title text:''' "In my new scale, °X, 0 is Earths' {{asic}} record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed." || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on [https://wmo.asu.edu/content/world-lowest-temperature July 21, 1983]. The average surface temperature as of 2023, [https://climate.copernicus.eu/climate-indicators/temperature the most recent available], is 14.8°C (58.6°F.) The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), [https://wmo.asu.edu/content/world-highest-temperature recorded] on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.

{{cot|Derivation and graph}}
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:

1. Below 14.8°C (from –89.2°C to 14.8°C):
* 0 °X corresponds to –89.2°C
* 50 °X corresponds to 14.8°C

We calculate the slope m₁:

<center>m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48</center>

Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:

<center>50 = 0.48 × 14.8 + b₁</center>

<center>50 = 7.1 + b₁</center>

<center>b₁ = 50 – 7.1 = 42.9</center>

Thus, the equation for temperatures '''below 14.8°C''' is:

<center>'''X = 0.48 × C + 42.9'''</center>

2. Above 14.8°C (from 14.8°C to 56.7°C):
* 50 °X corresponds to 14.8°C
* 100 °X corresponds to 56.7°C

We calculate the slope m₂:

<center>m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19</center>

Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:

<center>50 = 1.19 × 14.8 + b₂</center>

<center>50 = 17.6 + b₂</center>

<center>b₂ = 50 – 17.6 = 32.4</center>

Thus, the equation for temperatures '''above 14.8°C''' is:

<center>'''X = 1.19 × C + 32.4'''</center>

;Freezing and boiling points of water

Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:

<center>X = 0.48 × 0 + 42.9 = 42.9</center>

So, '''the freezing point is 42.9 °X.'''

Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:

<center>X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4</center>

So, '''the boiling point is 151.4 °X.'''

[[File:XvsC.png|400px|center]]

See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.
{{cob}}
<center>Celsius = (°X – 42.9) / 0.48 if °X < 50; or (°X – 32.4) / 1.19 if °X ≥ 50.</center>
<center>°X = 0.48 × Celsius + 42.9 if Celsius < 14.8; or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.</center>

Due to average temperature records [https://www.space.com/last-12-months-broke-temperature-records increasing almost every year] as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While such °X values for everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.

("Surface" temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)
|}

[[File:Temperature Scales.png|center|600px]]

===Examples===

Some temperatures in the above scales:

{| class=wikitable style="text-align: center;"
! Unit scale
! Typical {{w|room temperature}}
! {{w|Properties of water#Melting point|Freezing point of water}}
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}
! Midrange {{w|human body temperature|human body core temperature}}
! [https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature Recommended] {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}
! [https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety Recommended] {{w|Refrigerator#Freezer|freezer temperature}}
! [https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/ Typical] warm bath temperature
! Typical {{w|Coffee#Brewing|hot coffee}} temperature
|-
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C
|-
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K
|-
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F
|-
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré
|-
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø
|-
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra
|-
| Newton || 7.1 °N || 0 °N || 34 °N || 12 °N || 0.8 °N || –5.8 °N || 12.7 °N || 26 °N
|-
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W
|-
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8
|-
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23
|-
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6
|-
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X
|-
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8
|}

Here are the conversion formulas for the [[1923: Felsius|Felsius scale]]:
<center>Celsius = (Felsius − 16) / 1.4.</center>
<center>Felsius = Celsius * 7/5 + 16.</center>

==Transcript==

:Temperature Scales

:[A table with five columns, labelled: "Unit", "Water freezing point", "Water boiling point", "Notes", and "Cursedness". There are eleven rows below the labels.]

:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like "the hottest water you can hold your hand in", 7-ish/10
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is "normal"(?), 4/–4
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50

{{comic discussion}}

[[Category:Charts]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Science]]

3063: Planet Definitions

2025-07-27T15:04:22Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */ removed a repeated "the"

{{comic
| number = 3063
| date = March 14, 2025
| title = Planet Definitions
| image = planet_definitions_2x.png
| imagesize = 653x1435px
| noexpand = true
| titletext = Under the 'has cleared its orbital neighborhood' and 'fuses hydrogen into helium' definitions, thanks to human activities Earth technically no longer qualifies as a planet but DOES count as a star.
}}

==Explanation==
This comic addresses the {{w|IAU definition of planet|controversy of whether of Pluto is a planet}} and explores many definitions, most of them humorous and nonsensical, of what a planet could be.

{| class="wikitable sortable" style="margin:auto"
!colspan="2"|Definition !! # of planets !! Explanation
|-
! Traditionalist
| {{w|Pluto}} is a planet
| align=center | 9
| Until 2006, there was {{w|IAU definition of planet#Background|no official definition of a "planet"}}, but most people considered there to be nine, including Pluto, which was discovered in 1930. As astronomy advanced and larger objects like {{w|Eris (dwarf planet)|Eris}} were found, the {{w|International Astronomical Union}} redefined a planet as something that clears its orbit — disqualifying Pluto and Eris, now called "{{w|dwarf planets}}". This upset many who grew up learning Pluto was the ninth planet. Ironically, scientists are now searching for a new {{w|Planet Nine}}, which could again challenge the current definition. The 2006 redefinition of Pluto as a dwarf planet is a common theme on xkcd, occurring also in [[473: Still Raw]], [[482: Height]], [[1020: Orion Nebula]], [[1093: Forget]], [[1458: Small Moon]], [[1551: Pluto]], and [[1555: Exoplanet Names 2]].
|-
! Modern
| Pluto is not a planet
| align=center | 8
| When the IAU redefined what a planet is in 2006, Pluto no longer qualified as a planet since it wasn't able to clear its neighborhood around its orbit.
Using the modern, and recently official, definition of a planet, only eight celestial objects qualified: {{w|Mercury (planet)|Mercury}}, {{w|Venus (planet)|Venus}}, {{w|Earth (planet)|Earth}}, {{w|Mars (planet)|Mars}}, {{w|Jupiter (planet)|Jupiter}}, {{w|Saturn (planet)|Saturn}}, {{w|Uranus (planet)|Uranus}} and {{w|Neptune (planet)|Neptune}}.
|-
! Expansive
| Dwarf planets are planets
| align=center | 17+
| This category also includes nine other bodies that aren't dominant within their orbits, including the ones that are considered to have compacted into fully solid bodies {{w|Dwarf planet#Most likely dwarf planets|as defined by Grundy ''et al.''}}: {{w|Ceres (dwarf planet)|Ceres}}, Pluto, Eris, {{w|Makemake}}, {{w|Haumea}}, {{w|Gonggong (dwarf planet)|Gonggong}}, {{w|Quaoar}}, {{w|Orcus (dwarf planet)|Orcus}} and {{w|Sedna (dwarf planet)|Sedna}}.
The basis for this viewpoint is the possible alternative re-evaluation that the IAU could have adopted, in that all newly discovered things ''like'' Pluto (being considered a planet at the time) should therefore be considered a planet. Indeed, Ceres had been observed some time before Pluto and had been called a planet (or a "minor planet") within both scientific and public realms.
|-
! Ultratraditionalist
| Only the classical planets are planets
| align=center | 5
| The {{w|classical planets}} are objects found and considered by the Greek astronomers in classical antiquity to be considered planets. Their definition of "planet" considered visible objects that move across the sky relative to the fixed stars, the original word itself being translated as "wanderer".
There are seven classical planets, but this included the Sun and Moon. If one considers only the ones that also fall under either the IAU's definition of a planet (and so ''less'' traditional) or the convention before that, then there would be only five. Being mostly true to the spirit of the historic naming convention, this would be a conservative but 'valid' version of the criterion.

Notably, Earth itself is not considered a planet by these criteria as, from the perspective of anyone who might even consider such things, it is not wandering the heavens. Or even in the night skies at all, but always underfoot.
|-
! Condescending
| Only giant planets are planets; the rest are big {{w|asteroid}}s
| align=center | 4
| This definition may refer to the {{w|giant planets}}, planets much larger than the {{w|Earth}}. Only the four outer (IAU-defined) planets fall under this definition. Relegation of anything smaller, including our own planet, is an extreme attitude.
Incidentally, most of the initial [[:Category:Exoplanets|exoplanets]] discovered were, by practical necessity in their detection, also only of the "giant planet" kind.
|-
! Simplistic
| Anything gravitationally round is a planet
| align=center | 37+
| The Wikipedia {{w|list of gravitationally rounded objects of the Solar System}} has thirty-seven objects. It includes the Sun, eight planets, nine dwarf planets, nineteen {{w|Natural satellite|moon}}s, but falls short of also highlighting all of the smallest visible objects (per Universalist, below).
This definition is essentially ''part'' of the actual current definition of a planet, leaving out the main factor that disqualifies Pluto, orbital dominance.
|-
! Grounded
| Only objects a spaceship has landed on are planets
| align=center | 10
| This list includes objects in the Solar System that a spacecraft has {{w|List of landings on extraterrestrial bodies|performed a soft landing on}}. The list includes {{w|Venus}}, Earth, {{w|Mars}}, the Moon, {{w|Titan (moon)|Titan}}, the comet {{w|Churyumov-Gerasimenko}} plus the asteroids {{w|433 Eros|Eros}}, {{w|25143 Itokawa|Itokawa}}, {{w|162173 Ryugu|Ryugu}}, and {{w|101955 Bennu|Bennu}}.
The justification for this seems to be that we must 'touch' the object before we consider it as worthy of being classified as more than a mere blob (or dot) in space.

It could be argued that Jupiter and Saturn also count, due to the {{w|Galileo (spacecraft)|Galileo}} and {{w|Cassini–Huygens|Cassini}} spacecraft respectively, which plunged into the atmospheres of those planets.
|-
! Regolithic
| Anything covered in dirt and ice and stuff is a planet
| align=center | Infinite
| This list excludes the {{w|gas giant}}s and {{w|ice giant}}s. The list would likely include all other planets, plus all dwarf planets, asteroids, moons, comets and {{w|Oort cloud#Structure and composition|trillions of other objects}} in the {{w|Oort cloud}} that are larger than a few particles in size. (Not strictly infinite, but uncountably many for all practical reasons.)
This is effectively the opposite of the "condescending" definition: every object in the Solar System except the Sun is included in one definition or the other.
This is also an extension on the "Grounded" classification. In this case we ''could'' meaningfully touch the object, with predominantly atmospheric bodies being not considered so.
|-
! Lunar
| You can't be a planet if you don't have a moon
| align=center | 12+
| Only some objects in the solar system have known moons orbiting them. The value given may be {{w|List of natural satellites|the number of planets and dwarf planets}} that have moons, excluding {{w|Haumea}} for not {{w|hydrostatic equilibrium|being spherical}} despite having moons.
Adopting this definition would suggest that a planetary body is not worthy of the name if it doesn't demonstrably dominate its orbit by having at least one satellite of its own.

If this statement were "You can't be a planet if you don't have a Moon", ''only'' the Earth would qualify.
|-
! Solipsistic
| Earth is the only planet
| align=center | 1
| {{w|Solipsism}} is the idea that only one's own mind is sure to exist. Randall extrapolated this idea to mean that only one's own planet that they are standing on is sure to exist.
This relies on a more philosophical and/or semiotic assessment than any scientific one.
|-
! Judgemental
| Only the prettiest ones are planets
| align=center | 6
| This list is likely formulated from Randall's own perception of the prettiest planets in the Solar System. Seven objects are highlighted: Earth, Jupiter, one of Jupiter's moons (likely {{w|Europa (moon)|Europa}}, based on [[1547: Solar System Questions]]), Saturn, one of Saturn's moons (possibly Iapetus or Phoebe), {{w|Triton (moon)|Triton}} and Pluto.
The subjectivity of this version of the definition makes it unlikely that a consensus of this form could be established.
|-
! Empiricist
| Only worlds that I, author of this table, have personally seen are planets
| align=center | 12
| This list may refer to the celestial objects in the Solar System that have been visible at night for the author (or that the author has never seen the Sun), probably going so far as using an optical telescope (which could be a hobbyist one, perhaps Randall's own, or from time granted on a major institutional installation) but not any more indirect method that uses a camera/screen or historic images of any kind. Apparently Randall has seen Uranus, which technically [https://www.skyatnightmagazine.com/advice/skills/how-see-uranus-in-night-sky ''is'' visible to the naked eye] under the very best viewing conditions, but these conditions are rare and it requires knowing exactly where to look. Jupiter's {{w|Galilean moons|four largest moons}} are [https://web.archive.org/web/20201112024151/http://denisdutton.com/jupiter_moons.htm technically visible to the naked eye] but hard to distinguish due to Jupiter's brightness, while Neptune is considered too faint to see even if you know where to look. It appears that Randall has never used a telescope to see Neptune.
As a different form of subjectivity, the value of this grouping's criteria is questionable, but not uncommon in other 'softer' sciences.
|-
! Marine biologist
| Only objects with oceans are planets
| align=center | 6+
| This list includes Earth, {{w|Europa (moon)|Europa}}, {{w|Ganymede (moon)|Ganymede}}, {{w|Callisto (moon)|Callisto}}, Titan and {{w|Enceladus}}. These have had the presence of significant liquid identified from measurements of their magnetic/electric fields, but see the "Maritime" entry.
There is a resemblance, here, to a loose understanding of what a "world" is, i.e., one that possesses various distinct 'terrains' beyond mere dry (and possibly considered featureless) rock. A marine biologist would, of course consider a marine (if not pelagic or bathyspheric) environment to be an essential element of any world.
|-
! Maritime
| Only objects with ''surface'' oceans are planets
| align=center | 2
| In the comic, only Earth and Titan are highlighted. Earth is the only body known in the solar system to have liquid water on the surface significant enough to be called an ocean. Titan's cold and dense atmosphere notably maintains surface 'seas' of methane and nitrogen, while other moons (given as additional in the prior item) seem to have their liquid water beneath either whole-surface ice caps or otherwise deep under the surface.
From the narrower point of view of a sailor, for example, there is no benefit in considering water hidden away far beneath the surface, and it might as well not be there. In contrast, it's possible that a well-prepared mariner could sail the strange seas of Titan, as easily as (or easier than) {{w|Dragonfly (Titan space probe)|an aircraft}} might fly through {{what if|30|its skies}}.
|-
! Universalist
| They're all planets
| align=center | Infinite
| This list claims that all objects are planets, with all drawn items (also presumably all undrawn/undrawable items) being marked as such, including the Sun. Giving up on any thought of exclusivity, this unconventional view willingly inducts all objects into consideration, with an effectively equivalent claim to an infinite count as with the Regolith definition.
|-
! Existentialist
| What if {{w|outer space|space}} ''itself'' is a planet???
| align=center | ''Duude''
| This list is different from the list above as it claims that all of space, rather than only the objects existing in space, are planets. The interjection ''Duude'' expresses one's amazement at this 'revelation' and replaces the number count — and is sometimes used to imply [https://www.urbandictionary.com/define.php?term=duuuude the speaker is high] on marijuana or other mind-altering drugs.
The strange stretch of imagination, as prompted by some narcotic or other, abandons all pretense at sensibly sorting everything into "planet" or "not planet", as not only is everything a planet, but so is the nothing ''between'' these titular planets. However, the more serious subject of {{w|black hole cosmology}} holds the view that the observable universe is the interior of a black hole.
|-
! Spiteful
| ''Only'' Pluto is a planet
| align=center | 1
| This list is a malicious play on the demotion of Pluto by demoting all other planets except Pluto instead, leaving Pluto as the only planet in the solar system.
This is the taxonomic equivalent of refusing to play and taking your ball home to spite those who you think don't deserve to enjoy themselves.
|-
! {{w|Star}} (title text)
| Earth is a star
| align=center | 2 stars
| In May 1934, Mark Oliphant, Paul Harteck and Ernest Rutherford at the Cavendish Laboratory published an intentional deuterium fusion experiment and made the discovery of both tritium and helium-3. This is widely considered the first experimental demonstration of fusion. Randall considers that this and subsequent human-induced fusion makes Earth fall into the category of a star, and hence not a planet. Also, the IAU definition of a planet requires that the planet has cleared its "orbital neighborhood" of other objects — objects must either be captured as moons or have their orbits disrupted such that they are flung away.
Under this definition, one could humorously argue that recent human activities, launching into space ''new'' non-orbiting objects like the James Webb Space Telescope, technically disqualify Earth from being a planet, as the orbital neighborhood is no longer completely clear. By changing not only the definition, but the term being defined, this drifts yet further from any consensus view on the original question and into a typical punchline absurdity.
|}

==Transcript==

:[A table with 3 columns, and 17 rows below the header row, labelled "Definition", "# of planets" and "Solar system".]
:[In each row, the first column has a single word, in bold, then a descriptive sentence. The second column has a digit or other 'value'. The third column is a not-to-scale drawing of the Solar system, featuring the Sun, various 'planetary' bodies and an apparently selective sample of moons and asteroids, as follows: The Sun, Mercury, Venus, Earth with the Moon, Mars with its two moons (Phobos and Deimos), a small selection of some asteroid belt bodies (Ceres in the midst of other, smaller, examples), Jupiter and four of its moons (likely the Galilean moons: Io, Europa, Ganymede and Callisto), a ringed Saturn and usually one of its moons (probably Titan) or two (possibly Enceladus or Iapetus, as required), Uranus and four or five of its moons (likely to be Miranda, Ariel, Umbriel, Titania and Oberon, but one of these (shown upon the face of Uranus) only appears in some iterations of the base image), Neptune and one of its moons (probably Triton), Pluto and one of its moons (Charon, the main companion body possibly considered as fellow twin-dwarf instead), four more plutoid or Kuiper Belt objects (too little context to identify, but possibly Haumea, Makemake, Eris and Sedna, in distance order), the first two of them with distinct moons/companions indicated (the exact identities entirely dependent upon which main objects they are partnering).]
:[Each row's illustrated solar system has individual combinations of green highlights applied to the otherwise repeated diagram.]
:[Row 1: Definition:] Traditionalist: Pluto is a planet [Number:] 9 [Highlighted: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto]
:[Row 2: Definition:] Modern: Pluto is not a planet [Number:] 8 [Highlighted: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune]
:[Row 3: Definition:] Expansive: Dwarf planets are planets [Number:] 17+ [Highlighted: Mercury, Venus, Earth, Mars, Ceres (in Asteroid Belt), Jupiter, Saturn, Uranus, Neptune, Pluto and the further main bodies]
:[Row 4: Definition:] Ultratraditionalist: Only the classical planets are planets [Number:] 5 [Highlighted: Mercury, Venus, Mars, Jupiter, Saturn]
:[Row 5: Definition:] Condescending: Only giant planets are planets; the rest are big asteroids. [Number:] 4 [Highlighted: Jupiter, Saturn, Uranus, Neptune]
:[Row 6: Definition:] Simplistic: Anything gravitationally round is a planet [Number:] 37+ [Highlighted: The Sun, Mercury, Venus, Earth, The Moon, Mars, Ceres (without other asteroids), Jupiter + moons, Saturn with Titan, Uranus and its moons, Neptune with its moon, Pluto and the four further dwarf planets, your mom]
:[Row 7: Definition:] Grounded: Only objects a spaceship has landed on are planets [Number:] 10 [Highlighted: Venus, Earth, The Moon, Mars, five (non-Cererian) asteroids and Titan]
:[Row 8: Definition:] Regolithic: Anything covered in dirt and ice and stuff is a planet [Number:] [infinity symbol] [Highlighted: Mercury, Venus, Earth, The Moon, Mars, Ceres with all other asteroids depicted in the Asteroid Belt, the moons of Jupiter, the sole representative moon of Saturn, the moons of Uranus, the moon of Neptune, Pluto, Charon (Pluto's ’moon’/twin-dwarf companion) and all remaining dwarf planets together with their illustrated moons]
:[Row 9: Definition:] Lunar: You can't be a planet if you don't have a moon [Number:] 12+ [Highlighted: Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto and three of the other dwarf planets in the Kuiper belt, including one with no obviously drawn moon]
:[Row 10: Definition:] Solipsistic: Earth is the only planet [Number:] 1 [Highlighted: The Earth]
:[Row 11: Definition:] Judgemental: Only the prettiest ones are planets [Number:] 6 [Highlighted: The Earth, Jupiter with one of its moons (not identified), Saturn, one of ''two'' Saturnian moons in this image and Pluto]
:[Row 12: Definition:] Empiricist: Only worlds that I, author of this table, have personally seen are planets [Number:] 12 [Highlighted: Mercury, Venus, The Earth, The Moon, Mars, Jupiter with its four moons, Saturn and Uranus]
:[Row 13: Definition:] Marine biologist: Only objects with oceans are planets [Number:] 6+ [Highlighted: The Earth, three Jovian moons, the two illustrated Saturnian moons]
:[Row 14: Definition:] Maritime: Only objects with [next word in italics] surface oceans are planets [Number:] 2 [Highlighted: The Earth and Titan]
:[Row 15: Definition:] Universalist: They're all planets [Number:] [infinity symbol] [Highlighted: All drawn objects, including The Sun and all other objects including all the moons/asteroids]
:[Row 16: Definition:] Existentialist: What if space [next word in italics] itself is a planet??? [Word:] ''Duude'' [Highlighted: The whole third column cell]
:[Row 17: Definition:] Spiteful: [next word in italics] Only Pluto is a planet [Number:] 1 [Highlighted: Pluto]

==Trivia==
*In the [https://www.explainxkcd.com/wiki/images/archive/6/66/20250314195557%21planet_definitions_2x.png original version of the comic], there were two errors that would later be fixed. The "Traditionalist" definition highlighted Neptune's satellite {{w|Triton (moon)|Triton}} instead of Pluto. The images of the Solar System for the "Traditionalist" and "Modern" definitions were swapped, resulting in Pluto being incorrectly highlighted in "Modern" and omitted in "Traditionalist".

*The "Judgemental" definition has seven colored objects instead of the stated six. This mistake has not yet been fixed.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Charts]]
[[Category:Astronomy]]
[[Category:Space]]
[[Category:Philosophy]]
[[Category:Comics edited after their publication]]

3120: Geologic Periods

2025-07-27T15:02:18Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|{{w|Tanystropheus}} was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of Dracaena dragonblood trees
|Zanclean flood
|{{w|Dracaena draco}} and {{w|Dracaena cinnabari}} trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[A table with 3 columns, labelled: "Period", "My favorite part" and "My biggest complaint". There are 13 rows below the labels]
:[Row 1: Period:] ''Precambrian'' [My favorite part:] Life develops [My biggest complaint:] Snowball Earth episodes
:[Row 2: Period:] Cambrian [My favorite part:] Trilobites! [My biggest complaint:] Evolution could stand to calm down a little
:[Row 3: Period:] Ordovician [My favorite part:] Earth might have had rings [My biggest complaint:] Scary volcanic eruption in North America
:[Row 4: Period:] Silurian [My favorite part:] First land animals [My biggest complaint:] Earth's newfound mold problem
:[Row 5: Period:] Devonian [My favorite part:] Big mountains in Boston [My biggest complaint:] Yeah, sure, what those giant killer fish needed was '''''armor'''''
:[Row 6: Period:] Carboniferous [My favorite part:] Cool forests [My biggest complaint:] Bugs too big
:[Row 7: Period:] Permian [My favorite part:] Pangea [My biggest complaint:] Google "The Great Dying"
:[Row 8: Period:] Triassic [My favorite part:] Tanystropheus [accompanying the text is an image of a ''Tanystropheus'' and its characteristic elongated neck, with Cueball standing next to it for scale] [My biggest complaint:] Damage to Canada still visible from space at Manicouagan
:[Row 9: Period:] Jurassic [My favorite part:] Birds [My biggest complaint:] Parasitoid wasps
:[Row 10: Period:] Cretaceous [My favorite part:] Raptors [My biggest complaint:] Raptors
:[Row 11: Period:] Paleogene [My favorite part:] Pretty horseys!!! [My biggest complaint:] Paleocene-eocene thermal maximum
:[Row 12: Period:] Neogene [My favorite part:] Forests of ''Dracaena'' dragonblood trees [My biggest complaint:] Zanclean flood
:[Row 13: Period:] Quaternary [My favorite part:] Burrito invented [My biggest complaint:] Whoever picked the name for the third period of the Cenozoic

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]

3120: Geologic Periods

2025-07-27T15:01:40Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */ converted the table to plain text

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|{{w|Tanystropheus}} was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of Dracaena dragonblood trees
|Zanclean flood
|{{w|Dracaena draco}} and {{w|Dracaena cinnabari}} trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

[A table with 3 columns, labelled: "Period", "My favorite part" and "My biggest complaint". There are 13 rows below the labels]
[Row 1: Period:] ''Precambrian'' [My favorite part:] Life develops [My biggest complaint:] Snowball Earth episodes
[Row 2: Period:] Cambrian [My favorite part:] Trilobites! [My biggest complaint:] Evolution could stand to calm down a little
[Row 3: Period:] Ordovician [My favorite part:] Earth might have had rings [My biggest complaint:] Scary volcanic eruption in North America
[Row 4: Period:] Silurian [My favorite part:] First land animals [My biggest complaint:] Earth's newfound mold problem
[Row 5: Period:] Devonian [My favorite part:] Big mountains in Boston [My biggest complaint:] Yeah, sure, what those giant killer fish needed was '''''armor'''''
[Row 6: Period:] Carboniferous [My favorite part:] Cool forests [My biggest complaint:] Bugs too big
[Row 7: Period:] Permian [My favorite part:] Pangea [My biggest complaint:] Google "The Great Dying"
[Row 8: Period:] Triassic [My favorite part:] Tanystropheus [accompanying the text is an image of a ''Tanystropheus'' and its characteristic elongated neck, with Cueball standing next to it for scale] [My biggest complaint:] Damage to Canada still visible from space at Manicouagan
[Row 9: Period:] Jurassic [My favorite part:] Birds [My biggest complaint:] Parasitoid wasps
[Row 10: Period:] Cretaceous [My favorite part:] Raptors [My biggest complaint:] Raptors
[Row 11: Period:] Paleogene [My favorite part:] Pretty horseys!!! [My biggest complaint:] Paleocene-eocene thermal maximum
[Row 12: Period:] Neogene [My favorite part:] Forests of ''Dracaena'' dragonblood trees [My biggest complaint:] Zanclean flood
[Row 13: Period:] Quaternary [My favorite part:] Burrito invented [My biggest complaint:] Whoever picked the name for the third period of the Cenozoic

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]

3120: Geologic Periods

2025-07-27T13:24:26Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|{{w|Tanystropheus}} was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of Dracaena dragonblood trees
|Zanclean flood
|{{w|Dracaena draco}} and {{w|Dracaena cinnabari}} trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

{| class="wikitable"
!Period
!My favorite part
!My biggest complaint
|-
! ''Precambrian''
|Life develops
|Snowball Earth episodes
|-
! Cambrian
|Trilobites!
|Evolution could stand to calm down a little
|-
! Ordovician
|Earth might have had rings
|Scary volcanic eruption in North America
|-
! Silurian
|First land animals
|Earth's newfound mold problem
|-
! Devonian
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was '''''armor'''''
|-
! Carboniferous
|Cool forests
|Bugs too big
|-
! Permian
|Pangea
|Google "The Great Dying"
|-
! Triassic
|Tanystropheus [image of a ''Tanystropheus'' and its characteristic elongated neck next to Cueball for scale]
|Damage to Canada still visible from space at Manicouagan
|-
! Jurassic
|Birds
|Parasitoid wasps
|-
! Cretaceous
|Raptors
|Raptors
|-
! Paleogene
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|-
! Neogene
|Forests of ''Dracaena'' dragonblood trees
|Zanclean flood
|-
! Quaternary
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|}

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]

3120: Geologic Periods

2025-07-27T13:20:24Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|{{w|Tanystropheus}} was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of Dracaena dragonblood trees
|Zanclean flood
|{{w|Dracaena draco}} and {{w|Dracaena cinnabari}} trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

{| class="wikitable"
!Period
!My favorite part
!My biggest complaint
|-
! ''Precambrian''
|Life develops
|Snowball Earth episodes
|-
! Cambrian
|Trilobites!
|Evolution could stand to calm down a little
|-
! Ordovician
|Earth might have had rings
|Scary volcanic eruption in North America
|-
! Silurian
|First land animals
|Earth's newfound mold problem
|-
! Devonian
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|-
! Carboniferous
|Cool forests
|Bugs too big
|-
! Permian
|Pangea
|Google "The Great Dying"
|-
! Triassic
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|-
! Jurassic
|Birds
|Parasitoid wasps
|-
! Cretaceous
|Raptors
|Raptors
|-
! Paleogene
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|-
! Neogene
|Forests of ''Dracaena'' dragonblood trees
|Zanclean flood
|-
! Quaternary
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|}

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]

3120: Geologic Periods

2025-07-27T13:19:29Z

2A01:CB15:824D:FF00:5C0F:4AC8:B4CA:8C8E: /* Transcript */

{{comic
| number = 3120
| date = July 25, 2025
| title = Geologic Periods
| image = geologic_periods_2x.png
| imagesize = 611x557px
| noexpand = true
| titletext = Geologists claim it's because the earlier Cenozoic used to be called the Tertiary, but that's just a ruse to hide the secret third geologic period, between the Neogene and the Quaternary, that they won't tell us about.
}}

==Explanation==
{{incomplete|
*The article is missing a {{w|lead paragraph}}.

*This page was created by a Cretaceous raptor.

*The title text is missing}}

{| class="wikitable"
!Period
!Date range ({{abbr|{{w|Million years ago|MYA}}|Millions of years ago}})
!Randall's favorite part
!Randall's biggest complaint
!Explanation
|-
! Precambrian
|4500⁠–⁠539
|Life develops
|Snowball Earth episodes
|The {{w|Precambrian}} (italicized in the comic since it's not a {{w|Period (geology)|geologic period}}) is the first 88% of Earth's history, including the time 4.1 to 3.4 billion years ago when life on Earth began. The {{w|Snowball Earth}} hypothesis says that during some time spans in the past, Earth became nearly or entirely frozen, with no liquid water on the surface. It's related to the idea of the {{w|Greenhouse_and_icehouse_Earth#Icehouse_Earth|icehouse Earth}}, times when the planet fluctuates between glacial and interglacial periods (such as now).
|-
! {{w|Cambrian}}
|539⁠–⁠487
|Trilobites!
|Evolution could stand to calm down a little
|The {{w|Cambrian explosion}} was a sudden radiation of complex life forms when nearly all important animal phyla, or precursors to them, appeared. {{w|Trilobite|Trilobites}}, a lineage of {{w|Arthropod|arthropods}} (related to present-day insects and spiders), was one of the groups that appeared during the Cambrian. Fossil trilobite specimens are abundant and charismatic, and attract the attention of amateur and professional enthusiasts.
|-
! {{w|Ordovician}}
|487⁠–⁠443
|Earth might have had rings
|Scary volcanic eruption in North America
|Due to the non-random location of impact of one type of meteorite, {{w|Rings_of_Earth|it is proposed}} that those have formed a planetary ring system around Earth before colliding with it. The volcanic eruption(s) that deposited the {{w|Deicke_and_Millbrig_bentonite_layers|Deicke and Millbrig ashfall layers}} during the Late Ordovician are thought to have been among the largest in the last 600 million years of Earth history. The volcano(es) involved may have been among those formed during the mountain-building event in what is now northeastern North America that is called the {{w|Taconic_orogeny|Taconic orogeny}}.
|-
! {{w|Silurian}}
|443⁠–⁠420
|First land animals
|Earth's newfound mold problem
|Green plants first became established on land during the Ordovician period, after having evolved ways to protect themselves from desiccation and ultraviolet light. During the Silurian, land animals (mostly arthropods resembling {{w|Kampecaris|millipedes}}) followed the plants and mycelial fungi ("mold") evolved to attack them and decompose their remains.
|-
! {{w|Devonian}}
|420⁠–⁠359
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|A series of mountain-building events, during the middle to late Devonian, that are collectively termed the {{w|Acadian orogeny}} resulted in a section of the present-day Appalachian Range from the Canadian maritimes to the Carolinas, including what is now the Boston area of Massachusetts. (At the time, Boston was in the tropics, just south of the equator.) {{w|Placoderm}} fishes, which were common in but did not survive the Devonian, were characterized by plates of {{w|Dermal_bone|dermal bone}} in the head and thoracic portions of the body. Not all placoderms were giants, or apex predators. The best guess as to why placoderm fishes had these bony plates is that they helped protect the fishes from predation by other placoderms.
|-
! {{w|Carboniferous}}
|359⁠–⁠299
|Cool forests
|Bugs too big
|The {{w|Carboniferous#Terrestrial_invertebrates|'bugs' in this period}} included the largest-ever known land invertebrate, a {{w|Arthropleura|2.6 m (8.5 ft) millipede-like animal}}; the largest-ever known flying insect, resembling a {{w|Meganeura|dragonfly with a wingspan of ~75 cm (30 in)}}; and a {{w|Pulmonoscorpius|70 cm (2 ft 4 in) scorpion}}.
|-
! {{w|Permian}}
|299⁠–⁠252
|Pangea
|Google "The Great Dying"
|{{w|Pangaea}} was the most recent supercontinent containing nearly all of Earth's landmass. The Great Dying, more formally known as the {{w|Permian-Triassic extinction event}}, occurred at the end of the Permian and is the most severe of Earth's {{w|Extinction_event#The_"Big_Five"_mass_extinctions|'Big Five' mass extinction events}}. In it, 81% of marine species and 70% of terrestrial vertebrate species were wiped out.
|-
! {{w|Triassic}}
|252⁠–⁠201
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|{{w|Tanystropheus}} was a basal archosaur (not a dinosaur) with a disproportionally long neck. {{w|Manicouagan Reservoir}} is a ring-shaped lake, the remains of the crater caused by a 5 km (3 mi) asteroid hitting {{w|Quebec}}.
|-
! {{w|Jurassic}}
|201⁠–⁠143
|Birds
|Parasitoid wasps
|Birds are cool.{{Citation needed}} Parasitoid wasps are not; their reproduction cycle is such a grisly process that it caused a {{w|Ichneumonidae#Darwin_and_the_Ichneumonidae|crisis of faith}} among 19th-century European scholars.
|-
! {{w|Cretaceous}}
|143⁠–⁠66
|Raptors
|Raptors
|[[:Category:Velociraptors|Raptors]]
|-
! {{w|Paleogene}}
|66⁠–⁠23
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|The {{w|Paleocene–Eocene Thermal Maximum}} was a time where the global average temperature rose by around 5-8 °C in a relatively short period of time.
|-
! {{w|Neogene}}
|23⁠–⁠2.6
|Forests of Dracaena dragonblood trees
|Zanclean flood
|{{w|Dracaena draco}} and {{w|Dracaena cinnabari}} trees are a source of {{w|dragon's blood}}, a naturally occurring bright red resin with uses including as a varnish and a dye.
The {{w|Zanclean flood}} is theorized to be the flood that refilled the Mediterranean Sea.
|-
! {{w|Quaternary}}
|2.6⁠–⁠present
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|Randall jokes that, in the last 2.6 million years, his favorite moment was the invention of the {{w|burrito}}, rather than many other, much more significant discoveries. The precise origin of the burrito is not known, but the {{w|Maya civilization}} used to make food resembling burritos as early as 1500 BC.
The third period of the {{w|Cenozoic}} Era is the Quaternary era, named by Jules Desnoyers in 1829. This naming is controversial; the {{w|International Commission on Stratigraphy}} is proposing to abolish it.
|}

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

{| class="wikitable"
!Period
!My favorite part
!My biggest complaint
|-
! Precambrian
|Life develops
|Snowball Earth episodes
|-
! Cambrian
|Trilobites!
|Evolution could stand to calm down a little
|-
! Ordovician
|Earth might have had rings
|Scary volcanic eruption in North America
|-
! Silurian
|First land animals
|Earth's newfound mold problem
|-
! Devonian
|Big mountains in Boston
|Yeah, sure, what those giant killer fish needed was ''armor''
|-
! Carboniferous
|Cool forests
|Bugs too big
|-
! Permian
|Pangea
|Google "The Great Dying"
|-
! Triassic
|Tanystropheus
|Damage to Canada still visible from space at Manicouagan
|-
! Jurassic
|Birds
|Parasitoid wasps
|-
! Cretaceous
|Raptors
|Raptors
|-
! Paleogene
|Pretty horseys!!!
|Paleocene-eocene thermal maximum
|-
! Neogene
|Forests of Dracaena dragonblood trees
|Zanclean flood
|-
! Quaternary
|Burrito invented
|Whoever picked the name for the third period of the Cenozoic
|}

{{comic discussion}}<noinclude>
[[Category:Charts]]
[[Category:Geology]]
[[Category:Velociraptors]]
[[Category:Animals]]
[[Category:Food]]
[[Category:Comics featuring Cueball]]