Editing Talk:2121: Light Pollution
Please sign your posts with ~~~~ |
Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.
The edit can be undone.
Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 3: | Line 3: | ||
[[User:AlanKilian|AlanKilian]] ([[User talk:AlanKilian|talk]]) 16:03, 8 March 2019 (UTC) | [[User:AlanKilian|AlanKilian]] ([[User talk:AlanKilian|talk]]) 16:03, 8 March 2019 (UTC) | ||
:Six triangles form a hexagon - just an explanation for people with less mathematical or geometric knowledge. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:17, 8 March 2019 (UTC) | :Six triangles form a hexagon - just an explanation for people with less mathematical or geometric knowledge. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:17, 8 March 2019 (UTC) | ||
− | |||
::but a indefinite large group of triangles doesn't automatically transform to hexagons, since it could be overlapping hexagons, or hexagons with their interim spaces filled up by triangles?--[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 16:29, 8 March 2019 (UTC) | ::but a indefinite large group of triangles doesn't automatically transform to hexagons, since it could be overlapping hexagons, or hexagons with their interim spaces filled up by triangles?--[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 16:29, 8 March 2019 (UTC) | ||
:::Look at that hexagons (consisting of six triangles), each fitting to the next, and you will understand that this is only possible in a plane but not in a sphere. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:37, 8 March 2019 (UTC) | :::Look at that hexagons (consisting of six triangles), each fitting to the next, and you will understand that this is only possible in a plane but not in a sphere. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:37, 8 March 2019 (UTC) | ||
Line 9: | Line 8: | ||
:::::But can it form a [https://www.explainxkcd.com/wiki/index.php/1365:_Inflation basketball?] [[User:Netherin5|Netherin5]] ([[User talk:Netherin5|talk]]) 17:24, 8 March 2019 (UTC) | :::::But can it form a [https://www.explainxkcd.com/wiki/index.php/1365:_Inflation basketball?] [[User:Netherin5|Netherin5]] ([[User talk:Netherin5|talk]]) 17:24, 8 March 2019 (UTC) | ||
:Your eyes are making the hexagons up. Some triangles would be left over if you tried to make every group of 6 triangles a hexagon. Triangle arrays like this are commonly used in computer graphics, as they are the closest approximation to a sphere: https://mft-dev.dk/wp-content/uploads/2014/05/icosahedron_frame_sub3.gif [[Special:Contributions/162.158.79.185|162.158.79.185]] 17:25, 8 March 2019 (UTC) | :Your eyes are making the hexagons up. Some triangles would be left over if you tried to make every group of 6 triangles a hexagon. Triangle arrays like this are commonly used in computer graphics, as they are the closest approximation to a sphere: https://mft-dev.dk/wp-content/uploads/2014/05/icosahedron_frame_sub3.gif [[Special:Contributions/162.158.79.185|162.158.79.185]] 17:25, 8 March 2019 (UTC) | ||
− | ::Not really. On a plane, there are only three {{W|tesselation|tesselations}} made only of identical regular polygons: {{W|triangular tiling}}, {{W|square tiling}} or {{W|hexagonal tiling}}. But since a regular hexagon can be divided into six equilateral triangles, the tiling in the picture can be seen as both triangular and hexagonal. The leaving out you write about may have come from another tesselation which uses hexagons and triangles, the {{W|trihexagonal tiling}}. On a sphere, there's a completely different discussion as there's no tesselations, only approximations of them. {{unsigned|Malgond}} | + | ::Not really. On a plane, there are only three {{W|tesselation|tesselations}} made only of identical regular polygons: {{W|triangular tiling}}, {{W|square tiling}} or {{W|hexagonal tiling}}. But since a regular hexagon can be divided into six equilateral triangles, the tiling in the picture can be seen as both triangular and hexagonal. The leaving out you write about may have come from another tesselation which uses hexagons and triangles, the {{W|trihexagonal tiling}}. On a sphere, there's a completely different discussion as there's no tesselations, only approximations of them. {{unsigned|Malgond}} |
− | |||
There is no way to know that the triangles shown are equilateral (in fact, as drawn here they're quite ''un''even). All 3D renderings are in fact assembled from uneven-sided triangles, including renderings attempting to approximate rounded surfaces. And yes, you can buy a ball tiled only with triangles; they're not even-sided, but you can't tell with the naked eye. Also, there ''is'' one roughly spherical shape tiled only with equilateral triangles: It's the shape found on a 20-sided die. Skyboxes intended to minimize viewing angle distortions use triangles that are very nearly, but not quite equilateral. In fact, ''all shapes'' that use flat planes to tile a sphere can be broken down into triangles of one degree of asymmetry or another. Your argument is invalid. | There is no way to know that the triangles shown are equilateral (in fact, as drawn here they're quite ''un''even). All 3D renderings are in fact assembled from uneven-sided triangles, including renderings attempting to approximate rounded surfaces. And yes, you can buy a ball tiled only with triangles; they're not even-sided, but you can't tell with the naked eye. Also, there ''is'' one roughly spherical shape tiled only with equilateral triangles: It's the shape found on a 20-sided die. Skyboxes intended to minimize viewing angle distortions use triangles that are very nearly, but not quite equilateral. In fact, ''all shapes'' that use flat planes to tile a sphere can be broken down into triangles of one degree of asymmetry or another. Your argument is invalid. | ||
[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 22:51, 8 March 2019 (UTC) | [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 22:51, 8 March 2019 (UTC) | ||
− | |||
::Also note that we see just small part of sky there, so it's fully possible the few deformed/missing triangles are outside of what we see. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:49, 8 March 2019 (UTC) | ::Also note that we see just small part of sky there, so it's fully possible the few deformed/missing triangles are outside of what we see. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:49, 8 March 2019 (UTC) | ||
− | |||
− | |||
− | |||
Oh man where are the conspiracy nuts from a few weeks ago ;-) [[User:Cgrimes85|Cgrimes85]] ([[User talk:Cgrimes85|talk]]) 17:03, 8 March 2019 (UTC) | Oh man where are the conspiracy nuts from a few weeks ago ;-) [[User:Cgrimes85|Cgrimes85]] ([[User talk:Cgrimes85|talk]]) 17:03, 8 March 2019 (UTC) | ||
Line 31: | Line 25: | ||
:My thoughts exactly! it perfectly fits Spelljammer crystal spheres. I think it should be included in the explanation (and if not, then at least the source of the whole concept- https://en.wikipedia.org/wiki/The_Crystal_Spheres) [[Special:Contributions/162.158.92.34|162.158.92.34]] 00:13, 9 March 2019 (UTC) | :My thoughts exactly! it perfectly fits Spelljammer crystal spheres. I think it should be included in the explanation (and if not, then at least the source of the whole concept- https://en.wikipedia.org/wiki/The_Crystal_Spheres) [[Special:Contributions/162.158.92.34|162.158.92.34]] 00:13, 9 March 2019 (UTC) | ||
− | |||
I went to the sky at the end of [https://www.imdb.com/title/tt0139809/ Thirteenth Floor]. But the one image I can find suggests that was rectangular. [[User:Jordan Brown|Jordan Brown]] ([[User talk:Jordan Brown|talk]]) 21:47, 8 March 2019 (UTC) | I went to the sky at the end of [https://www.imdb.com/title/tt0139809/ Thirteenth Floor]. But the one image I can find suggests that was rectangular. [[User:Jordan Brown|Jordan Brown]] ([[User talk:Jordan Brown|talk]]) 21:47, 8 March 2019 (UTC) | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− |