Editing 1389: Surface Area
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| title = Surface Area | | title = Surface Area | ||
| image = surface_area.png | | image = surface_area.png | ||
− | | titletext = This isn't an informational illustration; this is a thing I think we should do. First, we'll need a gigantic spool of thread. Next, we'll need some kind of... hmm, time to head to Seattle. | + | | titletext = This isn't an informational illustration; this is a thing I think we should do. First, we'll need a gigantic spool of thread. Next, we'll need some kind of ... hmm, time to head to Seattle. |
}} | }} | ||
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− | + | A [http://xkcd.com/1389/large/ larger version] of this image can be found by clicking the image at xkcd - which can be reached easily from here as always, by clicking on the comic number above. | |
==Explanation== | ==Explanation== | ||
− | This map shows the total {{w|surface area}}s of all {{w|terrestrial planet}}s, {{w|dwarf planet}}s, {{w|natural satellite|moons}}, {{w|asteroid}}s and {{w|minor planet}}s that are larger than 100 m in the {{w|Solar System}}. They have all been represented as regions of a single massive landmass - a {{w|supercontinent}} like {{w|Pangaea}} - which is clearly surrounded by some kind of ocean | + | {{incomplete|There are still minor issues and clean up of the text left}} |
− | + | This map shows the total {{w|surface area}}s of all {{w|terrestrial planet}}s, {{w|dwarf planet}}s, {{w|natural satellite|moons}}, {{w|asteroid}}s and {{w|minor planet}}s that are larger than 100 m in the {{w|Solar System}}. They have all been represented as regions of a single massive landmass - a {{w|supercontinent}} like {{w|Pangaea}} - which is clearly surrounded by some kind of ocean. | |
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− | + | On the area that signifies {{w|Earth}} the {{w|continents}} are drawn using a {{w|map projection}} that keeps the scale of the continents correct. (This is something that [[Randall]] cares about as can be seen in [[977: Map Projections]]). The part of the surface of the Earth that are covered in oceans are also included in the surface area of the Earth, a layer of 3-4 km of water seems insignificant when comparing to the Earth's diameter of 12,000 km. | |
− | The | + | {{w|Moon|The Moon}} has been inlaid in this map next to {{w|Antarctic}} which thus makes a great comparison of how small the Moon is compared to the Earth. Similar it is clear that the planet {{w|Venus}} is almost as big as the earth. |
− | + | The objects mentioned by name on the map are all but one amongst those that have reached {{w|Hydrostatic equilibrium}} and these are all included on this {{w|List of gravitationally rounded objects of the Solar System}}. | |
− | + | The one named object that is '''not''' on the above list is the asteroid {{w|4 Vesta|Vesta}}, which is probably included and placed right next to the largest object in the {{w|Asteroid belt}}, the dwarf planet {{w|Ceres (dwarf planet)|Ceres}}, as it is the second largest object in the belt. | |
− | The | + | The only object from the above list, (that qualifies for having a solid surface in hydrostatic equilibrium), '''which is not included''' is the {{w|Saturn}} moon {{w|Mimas (moon)|Mimas}}, which is also clearly the smallest object on the list. This moon should have been located amongst the other smaller moons of Saturn between the Earth and {{w|Titan (moon)|Titan}} (the largest of Saturn's moons). Mimas has a surface area of 490,000 km<sup>2</sup> which is somewhat smaller than the smallest included Saturn moon {{w|Enceladus}} with a surface area of 799,000 km<sup>2</sup>. It could thus be that the small unlabeled area, located above the large asteroid area and to the left of {{w|Triton (moon)|Triton}} (a moon of {{w|Neptune}}), should represent Mimas. It is, however, strange to separate this moon from the other six included moons of Saturn. (See here below) |
− | + | Generally the moons that belong to a given planet (for those with more than one moon large enough to be included), have been clustered together. Apart from the six (not seven...) moons of Saturn to the right of Earth, the four {{w|Galilean moons}} moons of {{w|Jupiter}} are above the earth, the five included moons from {{w|Uranus}} is located to at the top to the far right. | |
− | + | The last planet to have many moons is Neptune, but only Triton is included. This is a fairly large moon, and the only of the 14 known moons of Neptune to be on the above list. However, there is one other moon, {{w|Proteus (moon)|Proteus}} which is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. It has a length of 424 km in the longest direction, and a mean radius of 210 km. A rough calculation of it's surface area from this mean radius gives an area of 550,000 km<sup>2</sup>, making the surface area slightly larger than Mimas. Since the '''unlabeled area''' is located right next to the other Neptune moon Triton, it is most likely that this small area '''should represent Proteus''', and that it is an error that it was not labeled (or it was a test for his followers...) | |
− | + | As this is the smallest area, then the cut-off of objects could have been at 500,000 km<sup>2</sup>, as also Vesta is larger than this, which would make room for Proteus, but explain the missing Mimas. | |
− | + | On the list from above there are, however, also these {{w|List_of_Solar_System_objects_in_hydrostatic_equilibrium#Most_likely_additional_dwarf_planets|10 objects}} which have not been included with name on the map. These object are, however, only likely candidates for being dwarf planets (depending on whether they have reached hydrostatic equilibrium or not), and on the map they have thus been relegated to the sections without individual names. These object are thus probably grouped together (along with other relatively small objects like comets and smaller moons) in the area labeled ''Various small moons, comets, etc'', which is located at the bottom of the map between {{w|Mercury (planet)|Mercury}} and {{w|Mars}}. The surface area for all of these object, when the surface area have been estimated, are larger than 1 million square kilometer, and thus larger than several of the named objects. So it is not the size that is the reason why such objects as {{w|90377 Sedna|Sedna}} and {{w|50000 Quaoar|Quaoar}} are not included with name, but probably the fact they are not investigated enough yet. | |
− | On the list from above there are, however, also these {{w| | ||
− | The remaining objects in the Solar System with a solid surface are the minor planets, which on the map has been labeled as asteroids even though these objects are grouped together in several other "belts" than the Asteroid belt. Here they have been assigned to two regions at the top of the map. Above the right part of the Earth area is the area ''Asteroids (1 km+)'' which include any object not already included larger than 1 | + | The remaining objects in the Solar System with a solid surface are the minor planets, which on the map has been labeled as asteroids even though these objects are grouped together in several other "belts" than the Asteroid belt. Here they have been assigned to two regions at the top of the map. Above the right part of the Earth area is the area ''Asteroids (1 km+)'' which include any object not already included larger than 1 km. (As these objects are no longer round it is the largest dimension, the length, that should be at least 1 km long). And finally the area ''Asteroids (100 m+)'' thus include any object not already included larger than 100 m. |
− | Most of the rest of the objects that have been included in these three sections can likely be found on this {{w|List of Solar System objects by size}} | + | Most of the rest of the objects that have been included in these three sections can likely be found on this list: {{w|List of Solar System objects by size}}. |
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− | + | Tiny objects smaller than 100 m down to space dust are excluded altogether as explained in the note below the headings. This is probably because their total surface area is impossible to estimate accurately, and also because any estimate would likely be too large to fit easily into the map. | |
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− | + | Between Earth and Titan is a tiny speck noted ''all human skin'', which is an interesting sort of solid surface. A very rough estimate of the average area of a {{w|Human skin|humans skin}} could be about 1 m<sup>2</sup>. Adults have a skin area of between 1.5-2 m<sup>2</sup>, but as a large part of the [https://www.census.gov/popclock/ human population] are children (with skin area down to about 0.25 m<sup>2</sup> for infants) a total average of 1 m<sup>2</sup> seems a reasonable guess. This would make the area 7.2 billion × 1m<sup>2</sup> ≈ 7000 km<sup>2</sup>. This is 100 times smaller than the smallest of the labeled moons {{w|Miranda (moon)|Miranda}} (of Uranus) with a surface area of 700,000 km<sup>2</sup>. | |
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− | + | The title text explains that this comic is not actually for information, it is something Randall thinks we should really do - that is, to stitch all the solar system's solid surfaces together, as the sub-sub heading says. To do this, we would obviously need a giant spool of thread and then something he has to go get in Seattle... This must of course be the {{w|Space Needle}}, a needle like tower in Seattle, which should then be used in this grand project. | |
− | + | Since the land areas are on the surfaces of spheres, this would seem impossible as it would involve lots of deformation and be particularly challenging. It will also be very gruesome when he comes to the part of collecting (and stitching) all human skin together. The inclusion of this speck on the map is, however, also there to make it clear what the real intention is with the planets. Their surface is to be "skinned" of them, as you would have to do with the humans! Then it is all these "planet skins" that should be stitched together using the space needle. This also explains the ragged edges, and why the continents keep their correct size. It would make Randall into a planetary version of {{w|The Silence of the Lambs (film)|The Silence of the Lambs}} movies character ''{{w|Buffalo Bill (character)|Buffalo Bill}}'', a serial killer who tried to make a suit out of the skin from the womens he killed. | |
− | Since the land areas are on the surfaces of spheres, this would seem impossible as it would involve lots of deformation and be particularly challenging. It will also be very gruesome when he comes to the part of collecting (and stitching) all human skin together. The inclusion of this speck on the map is, however, also there to make it clear what the real intention is with the planets. Their surface is to be "skinned" of them, as you would have to do with the humans! Then it is all these "planet skins" that should be stitched together using the space needle. This also explains the ragged edges, and why the continents keep their correct size. It would make Randall into a planetary version of {{w|The Silence of the Lambs (film)|The Silence of the Lambs}} movies character ''{{w|Buffalo Bill (character)|Buffalo Bill}}'', a serial killer who tried to make a suit out of the skin from the | ||
− | Randall would also need quite a lot of space for the very large ocean. However, the whole supercontinent is just somewhere between 3-4 times larger than the area of the Earth. And the area of the entire image is less than 9 times the area of the earth. As the {{w|Sphere#Area|formula}} for calculation surface areas for {{w|sphere}}s (4*π*r<sup>2</sup>) goes with the radius (r) squared, the diameter of the planet needed for the experiment do not need to be larger than 3 times that of the earth. Although there are no objects in the Solar System with this particular size, it is still smaller than the {{w|gas giant}}s, the smallest of these have a radius of almost | + | Randall would also need quite a lot of space for the very large ocean. However, the whole supercontinent is just somewhere between 3-4 times larger than the area of the Earth. And the area of the entire image is less than 9 times the area of the earth. As the {{w|Sphere#Area|formula}} for calculation surface areas for {{w|sphere}}s (4*π*r<sup>2</sup>) goes with the radius (r) squared, the diameter of the planet needed for the experiment do not need to be larger than 3 times that of the earth. Although there are no objects in the Solar System with this particular size, it is still much much smaller than the {{w|gas giant}}s, the smallest of these have a radius of almost 4000 times that of the earth! {{w|Exoplanet}}s with this range of diameters have certainly been found, however, already at {{w|Exoplanet#Super-Earths.2C_mini-Neptunes.2C_and_gas_dwarfs|1.7 times the earth radius}} most planets size to be of the {{w|Super-Earth}} type and turns in to the {{w|Gas_dwarf#Gas_dwarf|gas dwarf}} type of planets. So an ocean of the size needed are not easy to come by... |
As has been explained above the earth's surface is included disregarding surface water (oceans) and the same is valid for other objects with surface water, as the Saturn moon Titan which has great lakes (or even oceans) of liquid {{w|methane}} on the surface or the Jupiter moon {{w|Europa (moon)|Europa}} which is covered in a deep ocean with a thick cap of ice. (Interestingly this moon is placed on the map very near to the continent of {{w|Europe}} - maybe for easy comparison of these two areas). | As has been explained above the earth's surface is included disregarding surface water (oceans) and the same is valid for other objects with surface water, as the Saturn moon Titan which has great lakes (or even oceans) of liquid {{w|methane}} on the surface or the Jupiter moon {{w|Europa (moon)|Europa}} which is covered in a deep ocean with a thick cap of ice. (Interestingly this moon is placed on the map very near to the continent of {{w|Europe}} - maybe for easy comparison of these two areas). | ||
− | + | The {{w|gas giant}}s Jupiter, Saturn, Uranus, and Neptune has, however, not been included because they do not have any "solid surfaces"; even if they had a solid core (which is itself not clear), this would not comprise any "surface". The gas giants are believed to lack any well-defined surface at all, with the gases that make them up simply becoming thinner and thinner with increasing distance from the planets' centers, eventually becoming indistinguishable from the interplanetary medium. But if they were included via some sort of surface definition, the map of this comic would become a tiny speck amongst the map of the gas giants. Similarly the surface of the {{w|Sun}} is also not considered a solid surface but hot {{w|Plasma_(physics)|plasma}}; if it was included it would reduce even a map of the gas giants to a tiny speck. | |
− | The gas | ||
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The map is drawn in a similar style to the two maps of the Internet that Randall has created in the past: | The map is drawn in a similar style to the two maps of the Internet that Randall has created in the past: | ||
− | *[[256: Online Communities]] | + | *[[256: Online Communities]] |
− | *[[802: Online Communities 2]] | + | *[[802: Online Communities 2]] |
===Data table=== | ===Data table=== | ||
Below is a table listing the object roughly in the order they would be read of the map (the same order as in the transcript.) But they can be sorted by each of the columns. | Below is a table listing the object roughly in the order they would be read of the map (the same order as in the transcript.) But they can be sorted by each of the columns. | ||
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{| class="wikitable sortable" | {| class="wikitable sortable" | ||
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!Object | !Object | ||
!Type | !Type | ||
− | !Surface area | + | !Surface area |
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− | |{{w| | + | |{{w|Io (moon)|Io}}||Moon of Jupiter||data-sort-value="41910000"| 4.191×10<sup>7</sup> km<sup>2</sup> (0.082 Earths) |
|- | |- | ||
− | |{{w| | + | |{{w|Callisto (moon)|Callisto}}||Moon of Jupiter||data-sort-value="73000000"| 7.30×10<sup>7</sup> km<sup>2</sup> (0.143 Earths) |
|- | |- | ||
− | |{{w| | + | |{{w|Europa (moon)|Europa}}||Moon of Jupiter||data-sort-value="30900000"| 3.09×10<sup>7</sup> km<sup>2</sup> (0.061 Earths) |
|- | |- | ||
− | |{{w| | + | |{{w|Ganymede (moon)|Ganymede}}||Moon of Jupiter||data-sort-value="87000000"| 8.70×10<sup>7</sup> km<sup>2</sup> (0.171 Earths) |
|- | |- | ||
− | |{{w| | + | |{{w|Ceres (dwarf planet)|Ceres}}||Dwarf planet||data-sort-value="2850000"| 2.85×10<sup>6</sup> km<sup>2</sup> |
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− | |{{w| | + | |{{w|4 Vesta|Vesta}}||Asteroid||data-sort-value="870000"| 8.7×10<sup>5</sup> km<sup>2</sup> |
|- | |- | ||
− | | | + | |Asteroids 1 km+||Asteroid||??? |
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− | | | + | |Asteroids 100 m+||Asteroid||??? |
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− | |{{w| | + | |{{w|Triton (moon)|Triton}}||Moon of Neptune||data-sort-value="23018000"| 2.3018×10<sup>7</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w| | + | |{{w|Ariel (moon)|Ariel}}||Moon of Uranus||data-sort-value="4211300"| 4.2113×10<sup>6</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w|Miranda (moon)|Miranda}}||Moon of Uranus||data-sort-value="700000"| | + | |{{w|Miranda (moon)|Miranda}}||Moon of Uranus||data-sort-value="700000"| 7×10<sup>5</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w| | + | |{{w|Umbriel (moon)|Umbriel}}||Moon of Uranus||data-sort-value="4296000"| 4.296×10<sup>6</sup> km<sup>2</sup> (0.008 Earths) |
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− | |{{w| | + | |{{w|Oberon (moon)|Oberon}}||Moon of Uranus||data-sort-value="7285000"| 7.285×10<sup>6</sup> km<sup>2</sup> |
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− | |{{w|Titania (moon)|Titania}}||Moon of Uranus||data-sort-value="7820000"| 7.82×10<sup>6</sup> | + | |{{w|Titania (moon)|Titania}}||Moon of Uranus||data-sort-value="7820000"| 7.82×10<sup>6</sup> km<sup>2</sup> |
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− | |{{w| | + | |{{w|Tethys (moon)|Tethys}}||Moon of Saturn||data-sort-value="3610000"| 3.61×10<sup>6</sup> km<sup>2</sup> |
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− | |{{w| | + | |{{w|Dione (moon)|Dione}}||Moon of Saturn||data-sort-value="3960000"| 3.96×10<sup>6</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w|Enceladus}}||Moon of Saturn||data-sort-value=" | + | |{{w|Enceladus|Enceladus}}||Moon of Saturn||data-sort-value="800000"| 8×10<sup>5</sup> km<sup>2</sup> |
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− | |{{w| | + | |{{w|Iapetus (moon)|Iapetus}}||Moon of Saturn||data-sort-value="6700000"| 6.7×10<sup>6</sup> km<sup>2</sup> |
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− | |{{w| | + | |{{w|Titan (moon)|Titan}}||Moon of Saturn||data-sort-value="83000000"| 8.3×10<sup>7</sup> km<sup>2</sup> |
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− | | | + | |{{w|Rhea (moon)|Rhea}}||Moon of Saturn||data-sort-value="7337000"| 7.337×10<sup>6</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w| | + | |{{w|Earth|Earth}}||Planet||data-sort-value="510072000"| 5.10072×10<sup>8</sup> km<sup>2</sup> |
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− | |{{w| | + | |{{w|Moon|The Moon}}||Moon of Earth||data-sort-value="37930000"| 3.793×10<sup>7</sup> km<sup>2</sup> |
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− | | | + | |All human skin|| ||data-sort-value="7000"| 7.2 billion × 1m<sup>2</sup> ≈ 7000 km<sup>2</sup> |
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− | |{{w| | + | |{{w|Mercury (planet)|Mercury}}||Planet||data-sort-value="74800000"| 7.48×10<sup>7</sup> km<sup>2</sup> (0.147 Earths) |
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− | | | + | |{{w|Mars|Mars}}||Planet||data-sort-value="144800000"| 1.448×10<sup>8</sup> km<sup>2</sup> (0.284 Earths) |
|- | |- | ||
− | | | + | |Various small moons, comets, etc.||||??? |
|- | |- | ||
− | |{{w| | + | |{{w|Haumea (dwarf planet)|Haumea}}||Dwarf planet||data-sort-value="6800000"| 6.8×10<sup>6</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w| | + | |{{w|Makemake (dwarf planet)|Makemake}}||Dwarf planet||data-sort-value="6900000"| 6.9×10<sup>6</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w|Eris (dwarf planet)|Eris}}||Dwarf planet||data-sort-value=" | + | |{{w|Eris (dwarf planet)|Eris}}||Dwarf planet||data-sort-value="17000000"| 1.7×10<sup>7</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w|Pluto}}||Dwarf planet||data-sort-value=" | + | |{{w|Pluto|Pluto}}||Dwarf planet||data-sort-value="16650000"| 1.665×10<sup>7</sup> km<sup>2</sup> (0.033 Earths) |
|- | |- | ||
− | |{{w|Charon (moon)|Charon}}||Moon of Pluto||data-sort-value="4580000"| 4.58×10<sup>6</sup> | + | |{{w|Charon (moon)|Charon}}||Moon of Pluto||data-sort-value="4580000"| 4.58×10<sup>6</sup> km<sup>2</sup> |
|- | |- | ||
− | |{{w|Venus}}||Planet||data-sort-value="460000000"| 4.60×10<sup>8</sup> | + | |{{w|Venus|Venus}}||Planet||data-sort-value="460000000"| 4.60×10<sup>8</sup> km<sup>2</sup> (0.902 Earths) |
|} | |} | ||
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:'''Space''' | :'''Space''' | ||
:Without the space | :Without the space | ||
− | :The Solar | + | :The Solar System’s solid surfaces stitched together |
:(Excluding dust and small rocks) | :(Excluding dust and small rocks) | ||
− | :[Below the headings there is a map with several distinct areas. Each area is labelled with a name or a description. This label is noted inside the area, except for areas that are too small; here the label is written outside and a line indicates which area the label belongs to. Only exception is the largest area, on which the contours of the | + | :[Below the headings there is a map with several distinct areas. Each area is labelled with a name or a description. This label is noted inside the area, except for areas that are too small; here the label is written outside and a line indicates which area the label belongs to. Only exception is the largest area, on which the contours of the Earth’s continents are drawn. Surrounding the map is wavy lines to indicate that this is either an island or one big super-continent placed in an even larger ocean.] |
− | :[Here below are the labels given as they appear in | + | :[Here below are the labels given as they appear in “normal” reading order in as read from left to right in the three main rows as will be indicated:] |
:[Row one, above the line defined by the general top of the Earth area:] | :[Row one, above the line defined by the general top of the Earth area:] | ||
:Io | :Io | ||
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{{comic discussion}} | {{comic discussion}} | ||
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