explain xkcd - User contributions [en]

Talk:3149: Measure Twice, Cut Once

2025-10-03T11:37:02Z

Fomalhaut:

FIRST!!!11 [[Special:Contributions/2001:67C:89C:702:1CE:1CE:BABE:3|2001:67C:89C:702:1CE:1CE:BABE:3]] 00:38, 2 October 2025 (UTC) a
:TH1RD! [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 00:57, 2 October 2025 (UTC)
::F1FT3EN7H!! [[User:Logalex8369|Logalex8369]] ([[User talk:Logalex8369|talk]]) 16:09, 2 October 2025 (UTC)

Measure once, shame on you. Cut twice, shame on me!
[[User:StapleFreeBatteries|StapleFreeBatteries]] ([[User talk:StapleFreeBatteries|talk]]) 00:57, 2 October 2025 (UTC)
:You know, that's not a bad proverb! [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 00:58, 2 October 2025 (UTC)
:: I will cut you! Shame on me. [[Special:Contributions/82.13.184.33|82.13.184.33]] 08:49, 2 October 2025 (UTC)

This is my first XKCD explained! [[Special:Contributions/108.254.160.57|108.254.160.57]] 00:59, 2 October 2025 (UTC)
:Hip hip hooray for you! You did a great job. [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 01:02, 2 October 2025 (UTC)
: OK - but how many times did you check it before saving? [[Special:Contributions/82.13.184.33|82.13.184.33]] 08:49, 2 October 2025 (UTC)

A fundamental problem with this comic is that a "good carpenter" really means "an efficient carpenter" (true of any craftsman, really). Economy of motion, skilled enough to know when to be really precise and to know when precision doesn't matter and is a waste of time. The efficient carpenter doesn't need to measure twice, he or she gets it right on the first try. Or, consistent with the above, knows their capabilities well enough so they can only measure twice when it's truly necessary. And, of course, some of the best efficiencies come from not "measuring" at all — using an end stop or a jig so the cut is easy and repeatable without measurement. Drawing a line (or cutting without a line) against the actual reference point rather than against an intermediate measurement tool (some might call this "scribing," but that suggests a level of precision that isn't what I mean). Effectively, "measure zero times, cut once." And in the opposite, sometimes the most efficient approach is not to measure at all (whether numerically or against a reference object), but to make a rough cut and then a finish cut — effectively, "measure zero times, cut twice." Also possible is if you are gang cutting a stack of N boards, you measure 0 times or once and then make 1 cut, so on a per-board basis it's measure once, cut 1/N. I don't know that all of these things are obvious, per se, but I can't help feel surprised that they don't seem to have been considered. [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 06:38, 2 October 2025 (UTC)
: That seems to be more of an issue with the proverb, rather than the comic. [[Special:Contributions/82.13.184.33|82.13.184.33]] 08:49, 2 October 2025 (UTC)
:Are you saying my wall with studs just butt ended atop one another isn't good enough? Oh, fine then, I'll go add some bracing and maybe nails. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 11:07, 2 October 2025 (UTC)
::PLEASE STOP, YOU'RE KILLING ME!!!! --'''''[[User:DollarStoreBa'al|DollarStoreBa'al]][[User_talk:DollarStoreBa'al|converse]] 13:08, 2 October 2025 (UTC)
: I do not concur. (At least not fully...) When cutting timber, there are usually two dimensions to measure, and to make the perfect cut you must somehow have measured those to dimensions. A surgeon, on the other hand, must also use the third dimension, knowing how deep into the body they cut.
: Then, obviously, there are situations that differ. Say you want to half something, cutting along the diagonal. Or if you amputate a leg. But ''usually''! :) [[User:Fomalhaut|Fomalhaut]] ([[User talk:Fomalhaut|talk]]) 11:37, 3 October 2025 (UTC)

Somewhat disappointed there's no joke about quantum mechanics, even in the title text. I guess figuring out how to fit the uncertainty principle here is left as exercise to the reader? [[Special:Contributions/164.90.218.225|164.90.218.225]] 10:44, 2 October 2025 (UTC)

The title text seems to reference the Taoist concept of the uncarved block - https://en.wikipedia.org/wiki/Pu_(Taoism) {{unsigned ip|70.124.160.162|13:18, 2 October 2025}}

Possible reference to the real-life use of the reverse proverb (measure once cut twice) which is used by many makers. I am familiar with the concept from Adam Savage, but I don’t know if he’s the originator. The idea is that measurement is actually too imprecise of a tool and should only be used as an approximation. The final size of a piece will be based on something like a pressure fit. {{unsigned ip|98.36.13.95|14:24, 2 October 2025}}

About the title text, would the carpenter have to look or otherwise measure the wood to assume it's fine? Measure once, cut 0 times. {{unsigned|L0L0Z1993|15:19, 2 October 2025}}

[https://xkcd.com/467/ two measures one cut] [[Special:Contributions/2A0E:1D47:9098:3800:1126:180F:44A0:E826|2A0E:1D47:9098:3800:1126:180F:44A0:E826]] 18:07, 2 October 2025 (UTC)

Isn't this the 20th anniversary of XKCD? Strange that Randall wouldn't make a special comic! [[Special:Contributions/92.92.106.219|92.92.106.219]] 18:27, 2 October 2025 (UTC)
:Depends upon [[:Category:First day on xkcd.com|what you count the start as]].
:Also, is 20 years special enough to mark..? Maybe 0x20 years! Or 0x2A... [[Special:Contributions/82.132.215.216|82.132.215.216]] 19:26, 2 October 2025 (UTC)

My favorite option: "Measure never, cut forever!" Heard Bec Hill say this on the podcast A Problem Squared (don't ask me which episode). Couldn't find much about it online so for all I know she came up with it. It's catchy! --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 20:06, 2 October 2025 (UTC)

3063: Planet Definitions

2025-03-18T07:47:41Z

Fomalhaut: /* Explanation */ The pretty moon of Saturn probably isn't Titan

{{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==
{{incomplete|A table might be better to format the 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.

;Traditionalist: {{w|Pluto}} is a planet (9 planets)
:In modern times, there was {{w|IAU definition of planet#Background|no formal definition of a "planet"}} prior to 2006. However, it was generally accepted as a colloquialism that there were nine planets around the {{w|Sun}}, Pluto included. This view started primarily with Pluto's discovery in 1930, based upon that time's scientific consensus that there ought to be another planet to account for peculiarities in the the orbits of the other outer planets. As more sophisticated methods of mapping the {{w|Solar System}} were developed and {{w|Eris (dwarf planet)|Eris}} was discovered and found to be even more massive than Pluto (which may not have been as significant as the theories that led to its discovery suggested), it became clear to astronomers that a more standardized definition was needed. In 2006 the International Astronomical Union (IAU) published their formal redefinition of a "planet" to require a planet to be gravitationally dominant within its orbit, clearing other objects that aren't moons. This disqualified Pluto and Eris, which are now considered "{{w|dwarf planets}}". This has been subject to pushback from nostalgic laypeople dissatisfied with Pluto being "demoted" or otherwise relegated, when schoolchildren and adults alike have 'known' that there are nine planets for the most part of the last century.
:Ironically, some of the latest study of the outer Solar System includes the possibility of yet ''another'' {{w|Planet Nine}}, but only time will tell if such an object exists and whether it would cross the IAU's current threshold or even require the threshold itself to be reassessed once more.

;Modern: Pluto is not a planet (8 planets)
: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 (17+ planets)
: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 (5 planets)
: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, and if one considers only the ones that fall under the IAU's definition of a planet (and so ''less'' traditional), 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 prospective 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 (4 planets)
: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 (37+ planets)
: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 (10 planets)
: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}}, and 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 (infinite)
:This list excludes the {{w|gas giant}}s and {{w|ice giant}}s. The list would likely include dwarf planets, asteroids, moons, and the comets and {{w|Oort_cloud#Structure_and_composition|trillions of other objects}} in the {{w|Oort cloud}}. 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 prior 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 (12+ objects)
: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.

;Solipsistic: Earth is the only planet (1 planet)
:{{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 (6 planets)
: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 (12 planets)
:This list may refer to the celestial objects in the Solar System that have been made visible at night, probably using an optical telescope (a hobbyist one, perhaps Randall's, or from time borrowed on a major institutional installation). 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 (6+ planets)
: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 following item.
: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 (2 planets)
: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 (infinity)
: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.

;Existentialist: What if {{w|outer space|space}} ''itself'' is a planet??? (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 (1 planet)
: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. Because after all, what did Pluto do to deserve this? It's a planet, dammit! Let's remove the other eight and see how you like it!
:This is the taxonomic equivalent of refusing to play and taking your ball home to spite those who you think don't deserve it.

;(title text) {{w|Star}}: Earth is a star (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.

The paper "[https://arxiv.org/abs/2110.15285 Moons are planets: Scientific usefulness versus cultural teleology in the taxonomy of planetary science]" reviews the historical (and astrological) history of what is considered to be a planet within the folk taxonomy, lambasts the IAU definition as "rushed" before sorting out vital issues, recognises the history of science recognising moons as planets and suggests a definition of planets of any orbital state based on their unique complexity between a pile of rubble and an undifferentiated orb of fusing hydrogen and helium.

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]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A table with 3 columns, and 17 rows below the 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), four more plutoid or Kuiper Belt objects (too little context to identify, but possibly Haumea, Makemake, Eris, and maybe Sedna in distance order), the first two of them with distinct moons indicated (entirely dependent upon which main objects they are).]
:[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 moon! of Saturn, the moons of Uranus, the moon of Neptune, Pluto with Charon, and all remaining dwarf planets with their 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 labelled six. This mistake has never been fixed.

{{comic discussion}}

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

482: Height

2025-03-18T07:30:15Z

Fomalhaut: /* Objects */ 240 km rather than 100, according to the source linked in this table

{{comic
| number = 482
| date = September 29, 2008
| title = Height
| before = [[#Explanation|↓ Skip to explanation ↓]]
| image = height.png
| titletext = Interestingly, on a true vertical log plot, I think the Eiffel Tower's sides would really be straight lines.
}}
{{TOC}}

==Explanation==
''Height'' uses a {{w|logarithmic scale}} to depict the contents of the {{w|universe}} at progressively smaller distances from Earth (less high above the Earth), starting at the highest possible "point," the edge of the {{w|observable universe}}, going all the way down to the grass beneath our feet. The comic is a direct companion piece to [[485: Depth]], also released on a Monday the week after this one. ''Depth'' similarly uses the logarithmic scale to depict the Earth at progressively greater magnification (going "deeper" down), from Earth's surface (the grass) to the interior of a single proton.

The very top (edge) of the observable universe is described as being 46 billion {{w|light years}} above the Earth. The universe is "only" about {{w|Age of the universe|13.8 billion years old}}, so the {{w|cosmic background radiation}} that reaches the Earth today has also only traveled 13.8 billion light years. However, during that time, {{w|Metric expansion of space|the universe has expanded}}, so the galaxies that formed from that spot where this background radiation was emitted 13.8 billion years ago would now be 46 billion light years away. This has led to many {{w|Observable_universe#Misconceptions_on_its_size|misconceptions regarding the size}}, the most typical being that the radius of the observable universe is "only" 13.8 billion light years. See this video, ''[https://www.youtube.com/watch?v=QXfhGxZFcVE How Do You Measure the Size of the Universe?]'', for a great explanation of the 46 billion light years.

To the right of the text, [[Black Hat]] stands atop the comic, having just dropped a cat off the edge head first; he is clearly going to test if the cat will land on its feet, being a jerk per his usual character. It will take some time, though, before the cat reaches Earth....

As one scrolls down, the depicted distances become less compressed, until arriving at the surface of Earth, all the while approaching a 1:1 scale with real-life distances. As shown in [[1162: Log Scale]], if [[Randall]] didn't do this, the comic would be much, MUCH longer.

In this comic, most objects that are grounded on Earth are scaled logarithmically on the vertical axes and linearly on the horizontal axes (some are scaled linearly on both axes). Displaying objects in this manner noticeably distorts their shape; the Great Pyramid, for instance, looks not like a pyramid but like a bullet.

Outside of the Earth's atmosphere, the objects are placed at their actual distances from Earth on the log scale, but their shapes are not subjected to the logarithmic scaling of Earth objects, instead appearing as they would be seen (otherwise, round objects like the sun would appear more egg shaped, with the flatter side facing upward). However, objects are still much larger or much smaller than they would be in real life, in order to allow them to be properly seen.

In the title text, Randall muses on how the inwardly-curved sides of the {{w|Eiffel Tower}} might actually become perfectly straightened when subjected to this logarithmic distortion. Although it is shown to bulge in the comic proper, this may be a consequence of Randall's rough art style rather than any reflection of his beliefs. The actual shape of the Tower approximates an {{w|Exponential function|exponential curve}}, which would indeed give a straight line on a log scale, although it was actually designed by {{w|Gustave Eiffel}} to minimize wind resistance rather than to be mathematically exact (the design is so perfect that the amount the Tower sways in the wind is less than the amount it is distorted due to thermal expansion of the sunlit side).

===Objects===
All objects are sorted from bottom to top by their maximum distance from earth for objects in a solar orbit, and their current distance for others.

{| class="wikitable"
|-
! Distance
! Object
! Description
|-
| 435 ×1024m
| Black Hat and cat
| Black Hat dropping a cat off the top of the comic, presumably to determine whether it will land on its feet.
|-
| 435 ×1024m
| colspan="2" align="center" style="background: #ffdead;" | Top of {{w|observable universe}}
|-
| 11.3 ×1024m
| {{w|Hubble Deep Field}} objects
| Objects of extremely distant galaxies found in a long-exposure photograph by of the Hubble telescope, 12 billion light-years away. The rightmost object is probably intended to be a quasar, schematically shown from the side.
|-
| 9.46 ×1024m
| colspan="2" align="center" style="background: #ffdead;" | One billion light years
|-
| 3.1 ×1024m
| {{w|Quasar}}
| A supermassive black hole at the center of some young, distant galaxies, the energy released by stuff as it falls into them makes them the brightest known objects, the black hole eventually gets too big so the huge amounts of energy can't escape, but while they're active, they outshine entire clusters of galaxies.
|-
| 2.36 ×1024m
| {{w|Great Attractor}}
| An unusual concentration of intergalactic mass. (It could also just be [[502: Dark Flow|Your Mom]]).
|-
| 425 ×1021m
| {{w|Antennae Galaxies}} (colliding)
| A pair of colliding galaxies.
|-
| 23.6 ×1021m
| {{w|Andromeda Galaxy}}
| A sibling to our Milky Way. It is the nearest spiral galaxy to ours.
|-
| 23.6 ×1021m
| Holy crap lots of space
| There is a lot of {{w|Void (astronomy)|nearly empty space between galaxies}}.
|-
| 9.46 ×1021m
| colspan="2" align="center" style="background: #ffdead;" | One million light years
|-
| 2.38 ×1021m
| [http://knowyourmeme.com/memes/cat-on-a-keyboard-in-space Cat on a keyboard in space]
| An internet meme featuring a picture of a cat sitting on a musical keyboard, superimposed on an image of space.
|-
| 1.56 ×1021m
| {{w|Magellanic Clouds}}
| These clouds are a pair of nearby dwarf galaxies.
|-
| 263 ×1018m
| Edge of Galaxy
| The edge of the {{w|Milky Way}} galaxy, the galaxy in which we reside.
|-
| 245 ×1018m
| {{w|Galactic Center}}
| The center of the Milky Way galaxy.
|-
| 61.5 ×1018m
| {{w|Crab Nebula}}
| Nebula are supernova remnants.
|-
| 14.2 ×1018m
| {{w|Horsehead Nebula}}
| A dark nebula that is part of the Orion Constellation.
|-
| 12.7 ×1018m
| {{w|Orion Nebula}}
| A nebula that is part of the Orion Constellation, just south of Orion's Belt.
|-
| 8.14 ×1018m
| {{w|Rigel}}
| The brightest star in the Orion Constellation, it is actually a triple star system known alternatively as Beta Orionis.
|-
| 6.08 ×1018m
| {{w|Betelgeuse}}
| The star Betelgeuse is displayed along with the location of {{w|Ford_Prefect (character)|Ford Prefect}} on his home planet, which orbits Betelgeuse. Ford Prefect is a fictional character from the science fiction parody {{w|The Hitchhiker's Guide to the Galaxy}}.
|-
| 4.20 ×1018m
| {{w|Pleiades}}
| The Pleiades also have a derogatory remark (for those who do not know how to recognize them), as per [[66: Abusive Astronomy]]. This is probably because they are Randall's favorite astronomical entity as is stated at the very bottom of the [http://www.xkcd.com/about/ about] page on xkcd.
|-
| 2.90 ×1018m
| The [http://en.memory-alpha.org/wiki/Romulan_Neutral_Zone Romulan Neutral Zone]
| This marks the edge of the {{w|Star Trek}} Federation.
|-
| 931 ×1015m
| colspan="2" align="center" style="background: #ffdead;" | The first radio broadcast was in January 1910. Since radio waves travel at the speed of light, and this was published in September 2008, the radio waves traveled about 98.5 light years. See {{w|Contact (1997 film)}} for a depiction of this. This is also referenced in [[1212: Interstellar Memes]].
|-
| 350 ×1015m
| {{w|Arcturus}}
| An orange giant star that is part of the Boötes constellation.
|-
| 320 ×1015m
| {{w|Pollux}}
| One of the most distinct stars in the Gemini Constellation, it is large Orange Giant with an apparent visual magnitude of 1.1
|-
| 242 ×1015m
| The edge of {{w|Federation Sector 0-0-1}}
| The sector of space assigned to Earth in {{w|Star Trek}}.
|-
| 224 ×1015m
| {{w|Iraq and weapons of mass destruction|"missing WMDs"}}
| A reference to the alleged weapons of mass destruction that were used as a pretense to mobilize the world population against Iraq and start the Iraq war.
|-
| 81.3 ×1015m
| {{w|Sirius}}
|Also known as Alpha Canis Majoris or the Dog Star, it is actually a binary system of stars consisting of a main sequence white star and a small white dwarf.
|-
| 56.6 ×1015m
| {{w|Barnard's Star}}
| Barnard's Star is a very small red dwarf that is of great interest to astronomers as an achievement in the SIM ({{w|Space Interferometry Mission}}) to find a celestial object out of solar system that is as small as 3 earth masses.
|-
| 41.3 ×1015m
| {{w|Alpha Centauri}}
| Alpha Centauri is the closest star system to our planet.
|-
| 30.9 ×1015m
| colspan="2" align="center" style="background: #ffdead;" | One {{w|parsec}} (= 3.26 light-years).
|-
| 9.46 ×1015m
| colspan="2" align="center" style="background: #ffdead;" | One {{w|light-year}}.
|-
| 15.0 ×1015m
| {{w|Oort cloud}}
| A halo of ice balls surrounding our solar system, but missing the {{w|Kuiper belt}} between Neptune and the Oort cloud. The Oort cloud is only theorized to exist, with no confirmed direct observations, so Randall has written a question mark (?) next to this region of the graph.
|-
| 350 ×1012m
| {{w|Bupkis}}
| Yiddish for "nothing." Only a handful of objects are known to orbit between the Kuiper Belt and the Oort Cloud.
|-
| 55.0 ×1012m
| A comet that will destroy the Earth in late 2063.
| To coincide with the latest biblically-based prophesy for the [http://www.askelm.com/prophecy/p971105.htm end of the world].
|-
| 19.5 ×1012m
| {{w|Voyager 1}}
| An early space probe. Distance correct as of 20th Nov 2014, click [http://voyager.jpl.nasa.gov/where/ here] to see NASA's live distance counter.
|-
| 16.7 ×1012m
| {{w|Pioneer 10}}
| Listed distance is an estimate based on {{w|Pioneer_10#Current_status|this information}}.
|-
| 17.7 ×1012m
| {{w|Pioneer 11}}
| By the similarity in appearance to Pioneer 10, this unlabeled probe must be Pioneer 11. Listed distance is an estimate based on {{w|Pioneer_11#Current_status|this information}}.
|-
| 14.5 ×1012m
| {{w|Eris (dwarf planet)|Eris}}
| One of a pair of {{w|Trans-Neptunian object}}s now classified as {{w|dwarf planet}}s. The "All hail Discordia!" after Eris is a reference to {{w|Discordianism}}, a somewhat tongue-in-cheek religion based around the goddess Eris. The distance is the maximum distance from Earth.
|-
| 7.50 ×1012m
| {{w|Pluto}}
| One of a pair of {{w|Trans-Neptunian object}}s now classified as {{w|dwarf planet}}s. Pluto was originally classified as the 9th planet of the Solar system. Many people were appalled when it was suddenly degraded to dwarf planet. Obviously Randall does not think much of these people, thus the comment: ''Not a planet. Neener neener''. The distance is the maximum distance of Pluto from Earth.
|-
| 4.70 ×1012m
| {{w|Neptune}}
| Neptune is displayed here with its moons. Neptune is the eighth and final planet in our solar system.
|-
| 3.20 ×1012m
| {{w|Uranus}}
| Uranus is displayed here with its moons. Uranus is the seventh planet in our solar system.
|-
| 1.67 ×1012m
| {{w|Saturn}}
| Saturn is displayed along with its moons. One of Saturn's moons, most likely {{w|Enceladus}}, is labeled as a potential location to find life. Enceladus was known in 2008 to have a possible subsurface ocean and active geysers, and a paper co-authored by well-known planetary scientist Caroline Porco in Astrobiology during that year (when the comic was published) spelt out the case for searching for life there (McKay et al. 2008 "The Possible Origin and Persistence of Life on Enceladus and Detection of Biomarkers in the Plume," Astrobiology 8(5):909-919). In 2015, the {{w|Cassini probe}} sampled material thought to be from Enceladus' geysers, and scientists have found evidence that its subsurface ocean closely resembles a particular kind of deep sea hydrothermal environment on Earth known to harbor life.

A more distant possibility is that Randall is referencing Saturn's largest (and much more well known moons) {{w|Titan (moon)|Titan}}, the only known moon to have an atmosphere and lakes. It was long predicted that there may be bodies of liquid on the surface filled with liquid methane and ethane (Titan is too cold for liquid water and life as we know it, but ethane and methane remain a liquid at those temperatures). There is some speculation that exotic forms of life based on extremely cold exotic chemistries may form in such conditions, with liquid hydrocarbons playing the role of the solvent (the role water plays in terrestrial life).
|-
| 928 ×109m
| {{w|Jupiter}}
| Jupiter is displayed along with its moons. One of Jupiter's moons, {{w|Europa (moon)|Europa}}, is labeled as a potential location to find life. Europa may be covered by a deep ocean of water found under a layer of ice many kilometers thick. Some hypothesize that life could have formed in such oceans.
|-
| 222 ×109m
| Asteroids
| The {{w|Asteroid|Asteroid belt}} contains a spaceship from {{w|Asteroids (video game)}}
|-
| 133 ×109m
| {{w|Mars}}
| Note the path, reflecting the fact that their distances from Earth vary as the planets move in their orbits with a maximum distance of 401 million km and a minimum of 54.6 million km.
|-
| 114 ×109m
| {{w|Venus}}
| Note the path, reflecting the fact that their distances from Earth vary as the planets move in their orbits with a maximum distance of 261 million km and a minimum of 37.7 million km.
|-
| 138 ×109m
| {{w|Mercury}}
| Mercury is the innermost planet in our solar system. The distance shown is the maximum distance from Earth.
|-
| 149 ×109m
| {{w|Sun}}
| The Sun is the star at the center of our solar system, around which the Earth and the other planets orbit.
|-
| 16.3 ×109m
| {{w|Discovery One}}
| The Discovery One from {{w|2001: A Space Odyssey}}, referring to the quote "open the pod bay door, HAL." Also may be a reference to [[375: Pod Bay Doors]].
|-
| 9.43 ×109m
| Planet Express
| The spaceplane is most likely the Planet Express from {{w|Futurama}}, where Fry once discussed "a big heaping bowl of salt."
|-
| 400 ×106m
| {{w|Apollo_13#cite_ref-130|Human Altitude Record}}
| Achieved by the team of {{w|Apollo 13}} approximately 240 km higher than the remaining Apollo missions.
|-
| 384 ×106m
| {{w|Moon}}
| The Moon is the Earth's only natural satellite.
|-
| 90.4 ×106m
| {{w|Snoop Dogg}}
| A tongue-in-cheek reference to a rapper notorious for smoking marijuana, shown as having the second-highest altitude record. Someone who is taking drugs is said to be getting high.
|-
| 60.5 ×106m
| {{w|Space elevator}}
| A proposed method of transporting cargo or people into orbit, consisting of a large mass beyond geosynchronous orbit, a station at the geosynchronous point, a cable connecting it to the Earth, and a climber that can scale the cable. Space elevators are also seen in [[697: Tensile vs. Shear Strength]] and [[536: Space Elevators]].
|-
| 42.1 ×106m
| colspan="2" align="center" style="background: #ffdead;" | {{w|Geosynchronous orbit|Geosynchronous Orbit}}
|-
| 20.2 ×106m
| {{w|GPS (satellite)|GPS Satellites}}
| GPS satellites are used for global positioning.
|-
| 3.94 ×106m
| {{w|Lunar Lander}}
| The quote is a reference to {{w|Contact (1997 film)}}, where the main character Ellie Arroway after witnessing a celestial light show up close says "Poetry! They should've sent a poet."
|-
| 800 ×103m
| {{w|Space debris|Space Junk}}
| There is a large quantity of defunct objects in orbit around the Earth. Amongst other things, this includes old satellites, rocket stages, and fragments from collisions or disintegration. Space junk is also referenced in [[1242: Scary Names]] under the title {{w|Kessler syndrome}}.
|-
| 422.5 ×103m
| {{w|International Space Station}}
| The ISS (International Space Station) is a multinational effort to put a research vessel in space. It is currently the largest artificial object in Earth's orbit, as well as the location of the longest continuous human presence in space.
|-
| 100 ×103m
| colspan="2" align="center" style="background: #ffdead;" | The {{w|Edge of space|official edge of space}} as defined by the {{w|Kármán line}}.
|-
| 76.0 ×103m
| {{w|Meteors}}
| Meteors are chunks of rock (usually asteroids) that burn up in the atmosphere, producing the bright light associated with them. If they are large enough to hit the ground, they become meteorites, which is why Munroe labeled them only in the upper atmosphere.
|-
| 25.0 ×103m
| {{w|High-altitude balloon|High-altitude balloons}}
| Unmanned balloons, typically filled with helium or hydrogen. The current altitude record was set in 2002 by a balloon named BU60-1 that reached 53,000m.
|-
| 16.1 ×103m
| colspan="2" align="center" style="background: #ffdead;" | 1/10 ATM = 0.1 {{w|Atmospheric pressure|atmosphere of pressure}}
|-
| 12.0 ×103m
| {{w|Airliner|Airliners}}
| This is a typical cruising altitude of jet aircraft, equating to roughly 40,000 feet. (Aircraft altitude tends to be specified in feet rather than metres (yay!?))
|-
| 8.84 ×103m
| {{w|Mount Everest}}
| The Earth's highest mountain, located in the {{w|Himalayas|Himalayan mountain range}} in South Asia.
|-
| 8.00 ×103m
| [[Cory Doctorow]]
| Cory Doctorow is a [[:Category:Comics featuring Cory Doctorow|recurring theme]] in xkcd. He was first seen in a balloon in [[239: Blagofaire]].
|-
| 6.34 ×103m
| {{w|Space Shuttle Columbia disaster}}
| The {{w|Space Shuttle Columbia}} and its seven-member crew were lost when it disintegrated at [http://books.google.co.uk/books?id=6v16AgAAQBAJ&lpg=PA7&ots=LDKQ3nsNHs&dq=shuttle%20columbia%20altitude&pg=PA7#v=onepage&q=shuttle%20columbia%20altitude&f=false approximately 63,400m] in 2003. This number is inconsistent with the height of the graph by a factor of 10 (probably a mistype by Randall).
|-
| 6.00 ×103m
| {{w|Helicopter}}
| Though the record for helicopter altitude (without payload) is 12,442m, normal flying is usually performed much lower. In the US, 6000m is into {{w|Class A airspace}}, which is restricted and requires flight under {{w|Instrument Flight Rules}}.
|-
| 6.00 ×103m
| {{w|Cloud}}
| Though not actually labeled, there are a couple of clouds shown. While different cloud types vary in height, 6000m is roughly in the middle of the height range for [http://weatherfaqs.org.uk/node/21 clouds in temperate regions].
|-
| 5.49 ×103m
| colspan="2" align="center" style="background: #ffdead;" | 1/2 ATM = 0.5 {{w|Atmospheric pressure|atmosphere of pressure}}
|-
| 1.78 ×103m
| [[Cueball]]
| Apparently still using Python as shown in comic [[353: Python]].
|-
| 800 ×100m
| colspan="2" align="center" style="background: #ffdead;" | 800 meters
|-
| 800 ×100m
| {{w|Burj Khalifa|Burj Dubai}}
| Now known as the Burj Khalifa, it is the tallest building in the world. This was also a main feature in [[1110: Click and Drag]].
|-
| 500 ×100m
| colspan="2" align="center" style="background: #ffdead;" | 500 meters
|-
| 400 ×100m
| colspan="2" align="center" style="background: #ffdead;" | 400 meters
|-
| 325 ×100m
| {{w|Eiffel Tower}}
| A famous landmark in Paris, France.
|-
| 300 ×100m
| colspan="2" align="center" style="background: #ffdead;" | 300 meters
|-
| 200 ×100m
| colspan="2" align="center" style="background: #ffdead;" | 200 meters
|-
| 150 ×100m
| Kite
| Kite string is commonly sold in large spools; a nice thick spool will probably hold 150 meters. Kites are a [[:Category:Kites|recurring theme]] in xkcd; for instance, see [[235: Kite]].
|-
| 140 ×100m
| {{w|Great Pyramid of Giza}}
| One of the Seven Wonders of the Ancient World. It is located in Egypt.
|-
| 120 ×100m
| {{w|Pop fly}}
| In {{w|Baseball}}, a 'Pop Fly' is when the batter mis-hits the baseball, which then follows a tall arc deep into the infield where it's easy picking for the other team to catch on its way down. The highest recorded pop fly, not including those that landed in foul territory, was 172 meters.
|-
| 115 ×100m
| {{w|Redwood Tree|Redwood trees}}
| The tallest trees in the world. At 115.61 m (379.3 ft), {{w|Hyperion (tree)|Hyperion}}, a Coast Redwood, holds the record for the tallest tree in the world.
|-
| 100 ×100m
| colspan="2" align="center" style="background: #ffdead;" | 100 meters
|-
| 20.0 ×100m
| {{w|Oak}}
| While oaks may grow to be in excess of 40m in height, heights of around 20m are more typical. The person in the tree saying, "Hey, squirrels!" is a reference to [[167: Nihilism]].
|-
| 16.4 ×100m
| Tallest stilts
| The tallest {{w|stilts}} recorded by the Guinness Book of World Records (as of November 2006) were 16.4 meters, or nearly 54 feet. See also [http://www.explainxkcd.com/wiki/images/8/89/1608_1038x1095y_Hamsterball_and_stilts_room.png these tall stilts] from [[1608: Hoverboard]].
|-
| 13.0 ×100m
| {{w|Brachiosaurus|Brachiosaur}}
| A large genus of dinosaur.
|-
| 8.00 ×100m
| {{w|Giraffe}}
| The tallest living terrestrial animal, with fully grown adults reaching in excess of 5 m. While labeled 8m in the comic, the [http://www.big-animals.com/the-giraffe-the-worlds-tallest-animal/ record] for height is reported at 5.8m. Giraffes have been used by Randall for measuring heights, most prominently in the ''[[what if? (blog)|what if?]]'' ''{{what if|44|High Throw}}''.
|-
| 1.70 ×100m
| {{w|Human height|Folks}}
| Determining an average height of the world population is fraught with complications, but as a ballpark figure, 1.7m is fairly accurate.
|}

==Transcript==
:'''Top of observable universe'''
:[Black Hat is standing on top, throwing a black kitty down.]
:Black Cat: Mrowl!
:[Map of the universe from observable universe to Earth. Each area of item is labeled. Labels left to right, up to down:]
:(46 billion light years up)
::Hubble Deep Field Objects
:-One billion light years-
::Great Attractor
::Antennae Galaxies (colliding)
::Andromeda
::Holy crap lots of space
:-One million light years-
::Magellanic Clouds
::Edge of galaxy
::Galactic center
::Crab Nebula
::Orion Nebula
::Horsehead Nebula
::Romulan neutral zone
::The Pleiades, duh!
::Rigel
::Betelgeuse
::Ford Prefect
:[Three arrows are pointing up above three lines with the following label:]
:-Expanding shell of radio transmissions-
::[Above a dotted line:]
::Edge of federation sector 0-0-1
::Pollux
::Arcturus
::Missing WMDs
::Sirius
::Barnard's Star
::Alpha Centauri
:-One parsec-
:-One light year-
::Oort Cloud (?)
::Bupkis
::Comet which will destroy Earth in late 2063
::Pioneer 10
::Voyager I
::Eris (All hail Discordia!)
::Pluto (Not a planet. Neener neener.)
::Neptune
::Uranus
::Saturn
::[Two arrows point to two moons, one next to each of the planets above and below.]
::<-- Life -->
::Jupiter
::Asteroids
::Mars
::Venus
::Sun
::Mercury
::Spaceship Planet Express: Hey, a heaping bowl of salt!
::Spaceship Discovery One: Open the fridge door, Hal.
::Moon
::Human altitude record (Apollo 13)
::2nd place: Snoop Dogg
::Space elevator - One of these days, promise!
::Geosynchronous Orbit
::GPS satellites
::Lunar lander: In retrospect, they shouldn't have sent a poet. I have no idea how to land.
::International Space Station
::Space junk
:-Official edge of space (100 km)-
::Meteors
:-1/10 ATM-
::High altitude balloons
::Airliners
::Shuttle Columbia lost
:-1/2 ATM-
::Cory Doctrow
::Everest
::Helicopters (6000 m)
::Cueball: Woo Python!
::[A vertical scale is drawn along the right side of the picture, starting at 1 km and getting progressivly smaller and smaller.]
:1 km
:-800 m-
::Burj Dubai (~800 m)
:500
:400
::Eiffel Tower (325 m)
:200
::Kites
::Great Pyramid (140 m)
::Pop fly
::Redwood (115 m)
:100m
::Oak (20 m)
::A person in the oak: Hey squirrels!
::Tallest stilts
::Brachiosaur (13 m)
::Giraffe (8 m)
::[Megan and Cueball holding the kite are labeled:]
::Folks
:'''The observable universe, from top to bottom'''
::~On a log scale~
::Sizes are not to scale, but heights above the Earth's surface are accurate on a log scale. (That is, each step up is double the height.)

==Trivia==
This comic used to be [https://web.archive.org/web/20211215032218/https://store.xkcd.com/products/height-poster available as a poster] in the xkcd store before it was [[Store|shut down]].

{{comic discussion}}

[[Category:Charts]]
[[Category:Large drawings]]
[[Category:Illustrations of scale]]
[[Category:Comics with inverted brightness]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Cory Doctorow]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Space probes]]
[[Category:Astronomy]]
[[Category:Space]]
[[Category:Elevators]] 
[[Category:Baseball]]
[[Category:Animals]]
[[Category:Dinosaurs]]
[[Category:Giraffes]]
[[Category:Squirrels]] 
[[Category:Programming]] 
[[Category:Kites]]
[[Category:Star Trek]]
[[Category:Comics with xkcd store products]]
[[Category:Stilts]]

Talk:2825: Autumn and Fall

2023-09-11T14:24:49Z

Fomalhaut: 5 seasons in Swedish.

:Who calls it the "fall equinox"? I thought the equinoctes were always described as "vernal" and "autumnal"? [[User:Mathmannix|Mathmannix]] ([[User talk:Mathmannix|talk]]) 19:11, 6 September 2023 (UTC)

:: Americans sometimes call it the fall equinox casually [[Special:Contributions/172.71.158.100|172.71.158.100]] 19:56, 6 September 2023 (UTC)

:: In American English, "fall equinox" contrasts with "spring equinox" in the same way "summer solstice" contrasts with "winter solstice." The Latinate names are "autumnal equinox," "hibernal solstice," "vernal equinox," and "estival solstice," but since British English lost its non-Latinate name for the fall, the term "autumnal equinox" has to do double duty. The Latinate names are rather more common for equinoxes than solstices, but all four names are used. Also used are "September equinox," "December solstice," "March equinox," and "June solstice" if the context doesn't let you commit to one hemisphere or the other. [[Special:Contributions/108.162.216.74|108.162.216.74]] 09:20, 7 September 2023 (UTC)

:: Most people? It is the equinox that falls in Fall. So the Fall equinox. Like the summer and winter solstice. Which also invalidates anybody claiming the summer soltice being the last day of spring.[[Special:Contributions/172.69.150.102|172.69.150.102]] 16:08, 7 September 2023 (UTC)

:WRT the alt text, perhaps this is a woosh moment, but "fall" isn't at all common in British parlance. We know it, but only as an Americanism of what we would just call "Autumn". [[Special:Contributions/172.68.19.103|172.68.19.103]] 20:55, 6 September 2023 (UTC)
:: That's the joke. Just as Americans don't typically use "autumn", the UK does not use "fall". [[Special:Contributions/172.69.34.12|172.69.34.12]] 21:45, 6 September 2023 (UTC)

What "type of five-season system shown in the comic"? The comic doesn't show five-season system. It shows EIGHT season system. We just only know names of five of them. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:17, 6 September 2023 (UTC)

: That's the point, though: if the English language had an 8-season system, we'd have 8 names for them — but we only have 5. [[Special:Contributions/162.158.110.225|162.158.110.225]] 07:05, 7 September 2023 (UTC)

: Canada has 11 seasons with names for all of them: https://twitter.com/mathewi/status/1234532208423178241?lang=en (one of many variations on this meme, but rings very true if you live up north)

:Actually, I find there's no indication that Randall has any similar ideas about the other 3 seasons. It's quite possibly and even likely that he sees no such vagueness of feeling about Summer & Winter, and not really Spring either. Also, Autumn has "Fall" as a synonym for Randall to split up, I know no such synonyms for the other 3 seasons. [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:31, 10 September 2023 (UTC)

I think the statement "nowhere uses the type of five-season system shown in the comic." deserves an actual "citation needed" and not the joke one. Personally I didn't know about the six season thing in South Asia so it's not obvious that noone uses 5 seasons. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 11:07, 7 September 2023 (UTC)
::I definitely agree. I was going to comment the same thing.[[Special:Contributions/172.70.178.11|172.70.178.11]] 12:51, 7 September 2023 (UTC)
::The Hebrew bible, in the Book of Genesis (Gen. 8:22), establishes six seasons (consistent with the west-Asian origin story of the progenitors of the Hebrew race) of Sowing, Reaping, Cold, Heat, Summer, and Winter. {{unsigned ip|162.158.155.159|03:52, 8 September 2023}}
::Not really, I disagree, it's the typical "Can't prove a negative", what website/source is going to SAY "Nobody has 5 seasons"? It's something we just generally feel, even know, but I think it can only be DISproven, if someone finds a place that recognizes 5. It seems wrong to put "Citation Needed" for something which cannot be cited. [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:31, 10 September 2023 (UTC)

Can you believe it guys? First day of fall. Just a week away! First day of fall is in a week! Woohoo! I am so happy about this information. first day of fall, just a week away. Oh wow. Can you believe it? First day of fall! Just in a week! It got here so fast. First day of fall! [[Special:Contributions/172.71.22.39|172.71.22.39]] 11:51, 7 September 2023 (UTC)Bumpf

I'm surprised he didn't find a way to work in the "unofficial" seasons, which are based on holidays that straddle the periods of summer weather. In the US, Memorial Day is the unofficial start of summer, and Labor Day the unofficial end. They also coincide approximately with school summer breaks. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 14:20, 7 September 2023 (UTC)
: I just saw this comment, but that's exactly what I just added. :-) [[Special:Contributions/162.158.79.161|162.158.79.161]] 23:40, 7 September 2023 (UTC)

I'm just unreasonably pleased that someone of note is acknowledging that calling the equinoxes & solstices, the "start" of a season, is absurd from the standpoint of tracking the weather: The shortest day, occurring near the meteorological ''middle'' of winter even in the most delayed climates, is ''obviously not'' the "start" of winter, & likewise the weather shifts noticeably about a month before the vernal & autumnal equinoxes. The seemingly obligatory "first day of summer!" proclamations in the middle of June feel ''really'' disingenuous & annoying when much of the continent has already been seeing 90°F\32°C for weeks. '''By what means can we collectively petition to abolish this obviously incorrect practice''' & start ''properly'' referring to the solstices & equinoxes as the ''middle'' of their respective seasons, instead?
[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 16:30, 7 September 2023 (UTC)

:It's actually a classic trick question, "Do days get longer or shorter in winter?". Days are shorter (than in summer), yes, but given that winter quite famously can be said to {{w|Winter#Astronomical and other calendar-based reckoning|start on the shortest day}}, means that the answer is actually "longer", as the season heads towards the equinox and nights shorten from their maximum. (Either that or "neither, they're ''all'' 24 hours long" ...well, give or take the occasional leap second...)
:So, anyway, it's astronomical seasons. [[Special:Contributions/172.70.85.230|172.70.85.230]] 17:06, 7 September 2023 (UTC)
:As a science teacher, I feel this a lot. {{unsigned ip|162.158.155.159|03:52, 8 September 2023}}
::By the way, if you take a look at the difference between Gregorian and Julian calendars, the Gregorian calendar was designed to correct for the 0.25% imprecision of the Julian calendar, so Julian dates for the equinoxes and solstices are actually ~16 days later than Gregorian dates for the same. Hence why Orthodox religions observe different dates for Xmas and Easter. (Interestingly, the Jewish calendar was codified before the Gregorian calendar was proposed, and the Jewish calendar tries to unite lunar and solar cycles [according to the 19-year Metonic cycle], so Jewish dates having to do with the solar revolution are only accurate in the Julian calendar.) {{unsigned ip|162.158.155.160|04:00, 8 September 2023}}
:Speaking from the UK, starting summer in June seems entirely reasonable. What's idiotic is assuming that all the seasons are the same length - typically we have about three weeks of summer, a week and a half of winter, and the rest is spring/autumn.[[Special:Contributions/172.71.178.171|172.71.178.171]] 09:21, 11 September 2023 (UTC)

Interestingly, assuming that the September 1st is marked as the midnight (00:00hrs, otherwise identifiable as 24:00hrs of August 31st), the tick-marks being day-boundaries and the whole-bar mark being month-boundary, the position marked for the equinox appears to be ''very'' close to the time of 06:50 on the 23rd, which makes it agree with the ''UTC/UT1'' timing for this year's actual moment of south-bound equinox. Translated to Randall's presumed TZ at the time (-5, and +1 back for DST) surely it should happen to him significantly closer to the midnight marker, however. Not sure if he's being very clever or slightly sloppy. [[Special:Contributions/141.101.99.141|141.101.99.141]] 05:10, 8 September 2023 (UTC)

Regarding a five-season system, I immediately come to think of the situation in Sweden. There are the four standard seasons, but it's often mentioned that the Sami people has eight seasons. The only one of the four "intermediate" seasons used but the majority people (to some extent), is the "spring-winter". So, in the Swedish language it ''might'' be possible to talk about five seasons. :) [[User:Fomalhaut|Fomalhaut]] ([[User talk:Fomalhaut|talk]]) 14:24, 11 September 2023 (UTC)