explain xkcd - User contributions [en]

2976: Time Traveler Causes of Death

2024-08-23T19:31:06Z

Afmccune: /* Explanation */ Filled in remaining causes of death

{{comic
| number = 2976
| date = August 23, 2024
| title = Time Traveler Causes of Death
| image = time_traveler_causes_of_death_2x.png
| imagesize = 332x677px
| noexpand = true
| titletext = Many a hungry time traveler has Googled 'trilobites shellfish allergy' only to find their carrier had no coverage in the Ordovician.
}}

==Explanation==
{{incomplete|Created by a GOVERNMENT SUPPORTED SUICIDAL PERSON - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic showcases different causes of death for time travelers through the ages based on the geologic evolution of earth, from its formation over 4 billion years ago to the present.

{| class=wikitable
! scope="col" | Cause of death
! Scope=“col” | Time frame
! scope="col" | Explanation
|-
| Lava || Earth Forms || During the formation of the Earth, the surface was a hellish landscape of lava.
|-
| Asphyxiation || 4 billion years ago || Before Cyanobacteria started photosynthesising and producing oxygen, the atmosphere of the Earth was mainly composed of hydrogen sulphide, methane, and carbon dioxide. Humans need oxygen to breathe.{{Citation needed}}
|-
| Meteors || 3.9 billion years ago || During the {{w|Late Heavy Bombardment}}, the Earth's surface was subjected to a large number of asteroid and comet impacts, destroying much of Earth's early crust.
|-
| Slightly slower Asphyxiation || 2 billion years ago|| Cyanobacteria had started photosynthesising, but the oxygen levels weren’t large enough to support human life.
|-
| Freezing || Less than 1 billion years ago || During the {{w|Cryogenian|Cryogenian Ice Age}}, the Earth’s temperature fell to -12 degrees centigrade, much too cold to support human life.
|-
| Starving || 600 to 450 million years ago || During this time, the temperature was mild and comfortable, however, the only life during this time was single-cell organisms and – especially later – multicellular organisms, which humans cannot eat or would not tolerate.
|-
| Eaten by fish || 530-230 million years ago || During the {{w|Cambrian Explosion}}, there was an abundance of life which included, but was not limited to, giant fish.
|-
| Trampled || ||
|-
| Eaten by mammals || ||
|-
| Time machine door gets stuck || ||
|-
|}

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

:Top causes of death for time travelers by geologic era:

:Earth forms
::Lava
::Asphyxiation
:4 billion years ago
::Meteors
::Asphyxiation
:3 billion years ago
:2 billion years ago
::Slightly slower asphyxiation
:1 billion years ago
::Freezing
::Starving
:500 million years ago
::Eaten by fish
::Trampled
::Eaten by mammals
:Now
::Time machine door gets stuck

{{comic discussion}}

[[Category:Time travel]]

2836: A Halloween Carol

2023-10-02T20:25:42Z

Afmccune: /* Transcript */

{{comic
| number = 2836
| date = October 2, 2023
| title = A Halloween Carol
| image = a_halloween_carol_2x.png
| imagesize = 639x245px
| noexpand = true
| titletext = [after a minute] "Okay, I think I've got it, thanks. Can I--" "oOOOooOOooo!"
}}

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

In the classic Dickensian story {{w|A Christmas Carol}}, the protagonist of the tale is visited by various ghosts, first that of his old business partner and then (successively) the spirits of Christmases Past, Present and Yet To Come, in order to rehabilitate him from his anti-Christmas ways (and generally improve his humanity and spiritual future). In this case, however, three halloween-style ghosts arrive as a spoof of that tale. They represent similar phases of the actual festival of Halloween, but have turned up to pester Cueball in his bed all at the same time. And the 'lesson' they convey to him is far less transformative in nature. Since the ghosts say nothing further besides "oOOOOOOOOo," the lesson may be that Halloween has no "true meaning" or no true meaning different from what is obvious (compare the [[1108:_Cautionary_Ghost|Cautionary Ghost]]), or that the true meaning of Halloween consists of the kind of silly "scariness" represented by the sound "oOOOOOOOOo."

In the title text, in fact, it would appear that the very simple message has been received and taken on board, but the apparitions feel the need to continue their haunting regardless.

Caroling, though these days almost exclusively associated with Christmas, had long been a term for festive songs and dances, and arguably it is largely through Dickens's use as his story title that we associate it so strongly with this particular annual festival.

==Transcript==

{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is half sitting up in bed, his lower body underneath the blankets. He is looking at three ghosts flying above him.]
:Middle ghost: ooOOOOOooOOOoo
:[The "ooooo" of the ghosts is written in wavy letters of varying sizes]
:Middle ghost: We are the ghosts of halloween past, present and future

:[Just the middle ghost]
:Ghost: here to teach you the true meaning of halloween!

:[Back to the full scene]
:Left ghost: ooOOOOOOOooo
:Middle ghost: ooOOOOOooo

:[Again, the full scene]
:Left ghost: ooooooOOOooOooo
:Right ghost: ooOoooOOOoooo

==Trivia==
* '''This trivia section was created by a BOT'''
* The [https://imgs.xkcd.com/comics/a_halloween_carol_2x.png standard size] image was uploaded with a resolution/size larger than the supposed 2x version.
* This may have been an error.

{{comic discussion}}

2836: A Halloween Carol

2023-10-02T20:24:41Z

Afmccune: Suggested lessons being taught

{{comic
| number = 2836
| date = October 2, 2023
| title = A Halloween Carol
| image = a_halloween_carol_2x.png
| imagesize = 639x245px
| noexpand = true
| titletext = [after a minute] "Okay, I think I've got it, thanks. Can I--" "oOOOooOOooo!"
}}

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

In the classic Dickensian story {{w|A Christmas Carol}}, the protagonist of the tale is visited by various ghosts, first that of his old business partner and then (successively) the spirits of Christmases Past, Present and Yet To Come, in order to rehabilitate him from his anti-Christmas ways (and generally improve his humanity and spiritual future). In this case, however, three halloween-style ghosts arrive as a spoof of that tale. They represent similar phases of the actual festival of Halloween, but have turned up to pester Cueball in his bed all at the same time. And the 'lesson' they convey to him is far less transformative in nature. Since the ghosts say nothing further besides "oOOOOOOOOo," the lesson may be that Halloween has no "true meaning" or no true meaning different from what is obvious (compare the [[1108:_Cautionary_Ghost|Cautionary Ghost]]), or that the true meaning of Halloween consists of the kind of silly "scariness" represented by the sound "oOOOOOOOOo."

In the title text, in fact, it would appear that the very simple message has been received and taken on board, but the apparitions feel the need to continue their haunting regardless.

Caroling, though these days almost exclusively associated with Christmas, had long been a term for festive songs and dances, and arguably it is largely through Dickens's use as his story title that we associate it so strongly with this particular annual festival.

==Transcript==

{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is half sitting up in bed, his lower body underneath the blankets. He is looking at three ghost flying above him.]
:Middle ghost: ooOOOOOooOOOoo
:[The "ooooo" of the ghosts is written in wavy letters of varying sizes]
:Middle ghost: We are the ghosts of halloween past, present and future

:[Just the middle ghost]
:Ghost: here to teach you the true meaning of halloween!

:[Back to the full scene]
:Left ghost: ooOOOOOOOooo
:Middle ghost: ooOOOOOooo

:[Again, the full scene]
:Left ghost: ooooooOOOooOooo
:Right ghost: ooOoooOOOoooo

==Trivia==
* '''This trivia section was created by a BOT'''
* The [https://imgs.xkcd.com/comics/a_halloween_carol_2x.png standard size] image was uploaded with a resolution/size larger than the supposed 2x version.
* This may have been an error.

{{comic discussion}}

2780: Physical Quantities

2023-05-25T12:06:44Z

Afmccune: /* Explanation */

{{comic
| number = 2780
| date = May 24, 2023
| title = Physical Quantities
| image = physical_quantities_2x.png
| imagesize = 338x183px
| noexpand = true
| titletext = The Hubble length is about 1.9 meters lying down; Edwin Hubble was a tall guy.
}}

==Explanation==
{{incomplete|Created by a tall scientist - Do NOT delete this tag too soon.}}

This comic plays on the name of various established physical definitions by simply taking them overly literally. Each one is treated as being a bodily measure of the scientist after which they are named, rather than describing/estimating the objective feature within the scientist's field of study.

;Hubble volume
In cosmology, a {{w|Hubble volume}} (named for the astronomer {{w|Edwin Hubble}}) is a spherical region of the observable universe.
The Hubble volume is approximately equal to 1031 cubic light years (or about 1079 cubic meters).
The value given in the comic is the volume of Edwin Hubble's body.

;Schwarzschild radius
The {{w|Schwarzschild radius}} of a black hole refers to the event horizon: the radius beyond which light cannot escape. Curling up in a ball tends to reduce people's radii, so {{w|Karl Schwarzschild}}'s is given as 0.34 m, corresponding to a black hole of about 40 times the mass of Earth.

;Broca's area
{{w|Broca's area}} is part of the brain. It is not a measurement of area in the sense of length times width. The measurement shown here purports to be the area of {{w|Paul Broca}} (which might refer to the {{w|Body surface area|surface area of his body}}, or the area his body takes up), but it is given in cubic meters (a measure of volume) rather than square meters (a measure of area). (The surface area of an adult human is about two square meters.) This area was recently mentioned in the title text of [[2732: Bursa of Fabricius]].

;Fermi temperature
The concept of Fermi Temperature is {{w|Fermi energy#Related quantities|related to the Fermi Energy}}, a quantum value inherent to very cold substances. The {{w|Human body temperature|temperature of an average human}} is about 37 degrees Celsius, so it makes sense that {{w|Enrico Fermi}}’s temperature was 37 degrees Celsius, when he was alive. Today we can no longer test this, as he died in 1954.

;Planck length
{{w|Planck units}} are naturally-derived measurements invented by {{w|Max Planck}}; the Planck length (approximately 1.6×10-35 m) is one of the smallest meaningful distances. However, Randall measures the length of Max Planck, not the units. It is specifically when Planck was lying down (as to not decrease his height from a days exposure to gravity which may shorten a human by a centimeter or so, and also because lying down turns a human’s height into a length).

;Hubble length (title text)
A {{w|Hubble's_law#Hubble_length|Hubble length}} is 14.4 billion light years. This is a joke similar to the above play on the Planck length. The Hubble distance would be the distance between the Earth and the galaxies which are currently receding from us at the speed of light. The joke is that the Hubble length is 14 cm longer than the Planck length because Hubble was a tall man. Another joke by comparing these two are that these two distances are about as far from each other as possible on scales that make sense. The smallest distance to something on the order of the size of the visible universe.

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

:[A centered header appears above a list.]
:Reference Physical Quantities
:Hubble volume: 96L
:Schwarzchild radius: 0.34m (curled up)
:Broca's area: 1.7m3
:Fermi temperature: 37°C
:Planck length: 1.76m (lying down)

{{comic discussion}}
[[Category:Comics featuring real people]]
[[Category:Comics with lowercase text]]
[[Category:Astronomy]]
[[Category:Physics]]
[[Category:Biology]]
[[Category:Science]]

2780: Physical Quantities

2023-05-25T12:05:49Z

Afmccune: /* Explanation */

{{comic
| number = 2780
| date = May 24, 2023
| title = Physical Quantities
| image = physical_quantities_2x.png
| imagesize = 338x183px
| noexpand = true
| titletext = The Hubble length is about 1.9 meters lying down; Edwin Hubble was a tall guy.
}}

==Explanation==
{{incomplete|Created by a tall scientist - Do NOT delete this tag too soon.}}

This comic plays on the name of various established physical definitions by simply taking them overly literally. Each one is treated as being a bodily measure of the scientist after which they are named, rather than describing/estimating the objective feature within the scientist's field of study.

;Hubble volume
In cosmology, a {{w|Hubble volume}} (named for the astronomer {{w|Edwin Hubble}}) is a spherical region of the observable universe.
The Hubble volume is approximately equal to 1031 cubic light years (or about 1079 cubic meters).
The value given in the comic is the volume of Edwin Hubble's body.

;Schwarzschild radius
The {{w|Schwarzschild radius}} of a black hole refers to the event horizon: the radius beyond which light cannot escape. Curling up in a ball tends to reduce people's radii, so {{w|Karl Schwarzschild}}'s is given as 0.34 m, corresponding to a black hole of about 40 times the mass of Earth.

;Broca's area
{{w|Broca's area}} is part of the brain. It is not a measurement of area in the sense of length times width. The measurement shown here purports to be the area of {{w|Paul Broca}} (which might refer to the {{w|Body surface area|surface area of his body}}, or the area his body takes up), but it is given in cubic meters (a measure of volume) rather than square meters (a measure of area). (The surface area of an adult human is about two square meters.) This area was recently mentioned in the title text of [[2732: Bursa of Fabricius]].

;Fermi temperature
The concept of Fermi Temperature is {{w|Fermi energy#Related quantities|related to the Fermi Energy}}, a quantum value inherent to very cold substances. The {{w|Human body temperature|temperature of an average human}} is about 37 degrees Celsius, so it makes sense that {{w|Enrico Fermi}}’s temperature was 37 degrees Celsius, when he was alive. Today we can no longer test this, as he died in 1954.

;Planck length
{{w|Planck units}} are naturally-derived measurements invented by {{w|Max Planck}}; the Planck length (approximately 1.6×10-35 m) is one of the smallest meaningful distances. However, Randall measures the length of Max Planck, not the units. It is specifically when Planck was lying down (as to not decrease his height from a days exposure to gravity which may shorten a human by a centimeter or so, and also because lying down turns a human's height into a length).

;Hubble length (title text)
A {{w|Hubble's_law#Hubble_length|Hubble length}} is 14.4 billion light years. This is a joke similar to the above play on the Planck length. The Hubble distance would be the distance between the Earth and the galaxies which are currently receding from us at the speed of light. The joke is that the Hubble length is 14 cm longer than the Planck length because Hubble was a tall man. Another joke by comparing these two are that these two distances are about as far from each other as possible on scales that make sense. The smallest distance to something on the order of the size of the visible universe.

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

:[A centered header appears above a list.]
:Reference Physical Quantities
:Hubble volume: 96L
:Schwarzchild radius: 0.34m (curled up)
:Broca's area: 1.7m3
:Fermi temperature: 37°C
:Planck length: 1.76m (lying down)

{{comic discussion}}
[[Category:Comics featuring real people]]
[[Category:Comics with lowercase text]]
[[Category:Astronomy]]
[[Category:Physics]]
[[Category:Biology]]
[[Category:Science]]

764: One Two

2018-05-19T12:42:47Z

Afmccune: Added Pirahã language

{{comic
| number = 764
| date = July 9, 2010
| title = One Two
| image = one two.png
| titletext = Cue letters from anthropology majors complaining that this view of numerolinguistic development perpetuates a widespread myth. They get to write letters like that because when you're not getting a real science degree you have a lot of free time. Zing!
}}

==Explanation==
The comic parodies {{w|Sesame Street}}, an American children's TV show. The Count is a character in Sesame Street who teaches counting to viewers. The Count usually laughs after counting numbers, an innocent version of the sinister laugh that is a stereotype of old Hollywood horror films. In the book {{w|One Two Three ... Infinity}}, the writer describes African tribes that only have words for numbers up to three and their inability to distinguish or comprehend larger numbers. The {{w|Pirahã language}} of Brazil was originally thought to only have numerical terms for one, two, and many, although it is now thought these words are relative terms like "few" rather than absolute terms like "one." Similarly, see {{w|Edmund Blackadder}} try to teach {{tvtropes|BumblingSidekick|Baldrick}} [http://www.youtube.com/watch?v=u99LjJ32qOo to count beans].

In the title text Randall predicts that anthropology majors will write to complain that this view of primitive tribes is a myth no longer held true by today's anthropologists. He makes a jab at them saying they would have time to write letters to complain about things because they don't have to spend time doing real science and thus real research.

==Transcript==
:[A television set with The Count from 'Sesame Street'.]
:The Count: One! Ah ah ah... Two! Ah ah ah... ...Many! ah ah ah...
:Primitive cultures develop Sesame Street.

{{comic discussion}}
[[Category:Language]]