Talk:Montreal Biosphere

Photo request
Request for higher quality photos. Thanks. 69.236.110.131 18:26, 21 August 2006 (UTC) - Request for images of the structure before the and during the fire. — Preceding unsigned comment added by Ammobox (talk • contribs) 14:13, 19 April 2013 (UTC)

Expo 67 pavilion?
you don't even mention the fact that the building was the U.S.A. Pavilion at Expo '67!128.59.226.37 (talk) 20:39, 19 October 2008 (UTC)

acrylic bubble and material
Did they ever replace the acylic? I thought the frame is aluminum. Any word on those matters?--Anna Frodesiak (talk) 07:57, 19 February 2009 (UTC)

Move to "Montreal Biosphere"?
I notice that the title of the page (but nowhere else) has an accent grave on the (first) "e" in "Biosphere", but not an accent acute on the "e" in "Montreal". This seems inconsistent. The usual practice in the English-language Wikipedia is to use common English-language spellings. This would suggest titling the page "Montreal Biosphere" (but also noting the French-language spelling "Montréal Biosphère" or "La Biosphère de Montréal" near the top of the body text). — Preceding unsigned comment added by Rsfinlayson (talk • contribs) 03:48, 17 July 2018 (UTC)
 * Indeed this article should follow the common name guideline, and with that in mind, "Montreal Biosphere" is the correct spelling. Not only is that the name used in the English media and in print, but it's the official name listed on the government of Canada website. Its French name is "La Biosphère" (NOT 'Montreal Biosphère') so it's not even accurate in that sense. I would suggest adding a mention of its French name in the opening sentence though (e.g. "The Montreal Biosphere (French: La Biosphère) is a museum in Montreal dedicated to the environment."). There are several other Montreal related articles that should be corrected in the same manner (Montreal East, North and South for example), though I grew tired of the political outcries and nonsense that broke out for just trying to follow Wikipedia's own guidelines. At any rate, please feel free to move the article.--Apple2gs (talk) 05:16, 18 July 2018 (UTC)

OK, with no objections (and one vote of support), I went ahead and made the change. Ross Finlayson (talk) 17:27, 19 July 2018 (UTC)

polyhedrans and such
In the Pavilion section, the paragraphs about polyhedra I suspect is wrong on at least 2 counts: Firstly how this article explains Class 1 vs Class 2 and 3 geodesic polyhedra is wrong. See these links for the classes and underlying platonic solids role in the classification: https://en.wikipedia.org/wiki/Geodesic_polyhedron https://en.wikipedia.org/wiki/Goldberg_polyhedron https://en.wikipedia.org/wiki/List_of_geodesic_polyhedra_and_Goldberg_polyhedra Secondly I suspect that outside sphere is NOT Class 1 geodesic polyheran based on icosahedron. If it is then in order to make it look like a sphere you need to compensate by making the edges different lengths or curved. With identical straight edges it would take the shape of icosahedron. Is it may be Class 2? Unfortunately I don't know the answer or I would correct the article. What I would write is an accurate specs of both inner and outer sphere using official notation. And also the way in which they are joined. And also if the edges are equal length and straight or not. But I would drop the explanation of what classes are and how the frequency should be calculated. — Preceding unsigned comment added by ILIA.BROUDNO (talk • contribs) 07:50, 13 December 2020 (UTC)


 * The outside sphere does appear to be a Class 1 geodesic polyhedron at least going by the definition of class 1 on the first page you linked to (and staring at pictures of it for longer than I'd care to admit). It seems geometrically impossible to me that all of the edges are the same length in the shape which the biosphere is based on with this in mind considering that in the process of projecting to a sphere different parts of a subdivided line on the original icosahedron get distorted by different amounts. It is very hard to tell if the actual biosphere is truly based on a sphere or an ellipsoid or some less well known shape which would change its strut length but so long as the triangles of the icosahedron are not flat then the lengths are not all the same. Also, (despite looking quite deeply into it) I have not found any evidence that the frequency is based on the qualities described (number of triangles between two pentagonal centers) which state it to be 32, instead I have read only that the frequency (of a Class 1 dome) is the number of struts between pentagonal centers (for an icosahedral or dodecahedral based dome, other kinds do not even have obvious pentagons!).
 * TLDR: I think it is definitely a Class 1, I also believe it is definitely a frequency 16 dome and that the article is incorrect in stating that it is actually a frequency 32. I've only edited one other geometry related page before so I'm a little new to this. That being said I am happy to provide sources, diagrams, calculations, 3d models if necessary to explain exactly why I think these things. PineTheTree (talk) 00:32, 10 February 2024 (UTC)

There appear to be some inaccuracies in the Pavilion section
The Pavilion section describes the dome as being a 32 frequency dome and even claims that it is a common mistake to describe it as a 16 frequency dome... unfortunately, it is a 16 frequency dome. Judging based off of numerous guides to calculating the frequency of domes including the description found in this page: https://en.wikipedia.org/wiki/Geodesic_polyhedron Also the acclaimed geometer George Hart (https://en.wikipedia.org/wiki/George_W._Hart) states here that it is a 16 frequency dome: https://www.georgehart.com/MathCamp-2008/dome-two-layer.html I am not going to edit the page to delete such a large section unless either 1. Someone else recognizes the flaw and recommends fixing it or 2. More than a few days pass without any comment.

This same section also contains the claim that Class 1 domes are always icosahedral (which is false), Class 2 domes are dodecahedral (which is also false), and Class 3 domes are tetrahedral (which is... well, I think you can guess at this point). The shape of the inner layer is this: https://en.wikipedia.org/wiki/List_of_geodesic_polyhedra_and_Goldberg_polyhedra#/media/File:Conway_dccccD.png The outer layer is a Goldberg polyhedron, I believe this one: https://en.wikipedia.org/wiki/List_of_geodesic_polyhedra_and_Goldberg_polyhedra#/media/File:Conway_polyhedron_dk6k5adk6k5adk6k5at5daD.png Class 1, 2, and 3 domes are more about the path along the graph of the shape between two vertices with non-hexagonal connections, Class 1 is when that path is straight with no bends (just arcs on the sphere), Class 2 is when the bend is right in the middle of the path between the two non-hexagonal vertices and Class 3 is when there is a single bend somewhere other than the middle. I may need to go onto the geodesic polyhedra wikipedia page to clarify that a little, but not before this gets settled. Thank you very much for reading to the end, here is a smiley face C: PineTheTree (talk) 01:37, 10 February 2024 (UTC)