User talk:Tetracube

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Ruthenium[edit]

This made me smile :-) Materialscientist (talk) 00:57, 26 January 2010 (UTC)

Yeah it was a silly mistake... I was only looking at one diff and forgot that TW automatically reverts all edits by the same editor. Although in this case I'm inclined not to fix the inadvertent deletion of Yet Another Trivia Section. :-P—Tetracube (talk) 00:59, 26 January 2010 (UTC)

AfD nomination of SaaS integration[edit]

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Deleted Link[edit]

Dear Tetracube,

Thanks for your message, though my intention was by no means motivated by advertising/promotion to post the link on the Heptatis C virus page. I thought that it would be a legitimately quality overview of the virus for visitors. A friend of mine made it (and the SmartyMaps application) and it seems like something that would be quite useful in communicating spatial and physical relationships such as the structure of a virus. What do you think?

-Ryan —Preceding unsigned comment added by Ryanenglish (talkcontribs) 21:09, 30 March 2010 (UTC)

Please see WP:ELNO. External links to personal websites (or friends' websites) are generally discouraged. Note also WP:OR: Wikipedia is intended to include only research already published by reputable third-party sources (such as a scientific journal, etc., preferably peer-reviewed).—Tetracube (talk) 21:16, 30 March 2010 (UTC)

Apology from Yankeesrule3[edit]

Oops... Sorry about that on the periodic table.... I forgot to look at the talk page. That was really stupid. It was a good reminder to look on the talk page though. Yankeesrule3 (talk) 01:26, 21 April 2010 (UTC)

No harm done. I'm sorry I shouted so loudly.—Tetracube (talk) 01:43, 21 April 2010 (UTC)
No hard feelings. Yankeesrule3 (talk) 00:00, 24 April 2010 (UTC)

Hi, Tetracube - about denitrification...[edit]

Hi- One concern about the edits you made to the denitrification page - you took the capitals out of Genus names for the genre listed, and this is scientifically incorrect. (This is listed in the tutorial section.) No quibble about having puntuation before references - I prefer it that way - I just had a "heated discussion" on this subject with my academic advisor on the correct way to do this, and he insists that ref.s go inside the punctuation...SIGH...just can't win sometimes! ````

Sorry about the genus names. Please feel free to recapitalize them. I was under the impression that bacteria names weren't capitalized; I guess that isn't always the case. As for the "heated discussion", you might want to refer your advisor to Wikipedia:MOS#Punctuation_and_inline_citations: this is the preferred way to do it on Wikipedia, even if other places adopt a different convention.—Tetracube (talk) 00:35, 30 April 2010 (UTC)

Talk:Aluminium[edit]

I thought you had graduated...how dare you not admit that you are part of the "alumni"! DMacks (talk) 18:56, 6 May 2010 (UTC)

Because I'm Ni-free alum.—Tetracube (talk) 19:03, 6 May 2010 (UTC)

Was there a concensus that all pronunciations should be moved to infoboxes?[edit]

Was it even discussed? I'm not violently opposed, but it bothers me a little. It's not "lookup" number info, but really something more basic. Certainly as basic as anything else in the lede. Could we perhaps duplicate it? Or put just the IPA in the infobox and leave the phonetic in the lede? SBHarris 18:23, 7 May 2010 (UTC)

See Template_talk:Elementbox#Pronunciation, cf. Talk:Xenon#Location of pronunciation info. I agree with RJ in the latter, that inserting the pronunciation in the lede interrupts the flow of the text. I personally often find myself not even bothering to read the first sentence because it's hard to read with all those parenthetical pronunciation keys. Much better to put it in the table where it can be looked up when necessary. Pronunciation isn't really the most important issue when you're looking up info about a chemical element, after all.—Tetracube (talk) 18:30, 7 May 2010 (UTC)
Well, not to a chemist. But lay people don't know this stuff any more than anything else. Can YOU properly pronounce copernicium? It interupts the flow of thought to realize you can't say the name of the thing you're reading about, too. Which is why I suggest putting the ugly IPA stuff into the info box, but leaving the dictionary pronunciation where it is. SBHarris 19:08, 7 May 2010 (UTC)
I find the IPA much more readable than the respelling butchering of English orthography. But I suppose it wouldn't hurt to put one of them in the lede and leave the other in the infobox. Maybe you want to take up the discussion at Template_talk:Elementbox#Pronunciation instead?—Tetracube (talk) 19:15, 7 May 2010 (UTC)
I never understood why pronunciation was inserted in the first sentence of the lede. When I want to see how to pronouce something, I reach for a dictionary; not an encyclopedia. Wikipedia is the only encyclopedia I've seen where the practice of inserting pronunciation information at the top is even followed.
The guidelines for the lede say nothing about the pronunciation, but they do state that the lede is intended as a summary of the article. As the pronunciation is never included in the body, it is clearly not present in the lede as a summary.
I suppose it's a matter of opinion really, but I find pronunciation information in the lede a major annoyance when I just want to get to the information. (It's number 3 on my list of top wikipedia annoyances, along with too many hatnotes and too large of an opening image.) That's why I much prefer having it in the infobox. If you must have it in the lede, it should go at the bottom as it is usually one of least importance aspect of the topic.
Finally, I find the pronunciation information generally unintelligible and jargony. Once needs to be familiar with the symbology even to understand it properly, and I don't want to have to spend the time needed to do that. It's a bit like running across a higher level math or physics formula in a wikipedia article; if the reader is unfamiliar with math, then what good is it? I suppose one could slap a '[clarification needed]' template at the end.
Thanks for letting me spout. My $.02 worth.—RJH (talk) 19:41, 7 May 2010 (UTC)
I've left a note for RJHall as well: this is to let you know that I'm reverting the removal of pronunciation data from the ledes of all these articles until there's wider discussion. Such unilateral removals of material which there's a long-standing convention of including should be discussed centrally prior to being rolled out over dozens of articles. Thanks. Chris Cunningham (not at work) - talk 09:58, 15 July 2010 (UTC)

The lead sentence should be high impact (giving a very quick orientation and explanation of a topic that may be 20 pages+ long. It should also be extremely clear and inviting. IPA cruftiness is extremely NOT needed in that first sentence. Much better places to put it (if it really matters discuss etymology and such in text...or use the infobox). At the extreme example, we have people loading down the first sentence with roadbumps of Arabic, Chinese, IPA, and Eyptian hyroglyphics. Blech. 66.16.76.229 (talk) 20:32, 26 June 2012 (UTC)

rotation[edit]

I failed to find the process to perform a rotation about a point different from the origin in the article, and thought that article was well written and potentially useful for others looking for the same thing. Did I miss something in the article? Otherwise I think it does add value. Cheers, Waldir talk 19:45, 7 May 2010 (UTC)

It's very simple: you perform a translation T to move the rotational axis to the origin, do the rotation R, and then perform the inverse translation T−1 to move it back afterwards. In matrix notation, that would be T−1RT. Note also that you can also reorient the axis using a second rotation S, if you want to rotate about a non-orthogonal axis. You would then perform T−1S−1RST.—Tetracube (talk) 19:51, 7 May 2010 (UTC)
In fact, the second paragraph of the article describes this, although it could use some work to be clearer to someone who isn't a geometrician. :-)—Tetracube (talk) 19:54, 7 May 2010 (UTC)
Exactly :) I understood what you said above after reading the page I linked -- not after reading that paragraph. It'd be great if you could rework it a bit :) Waldir talk 22:05, 7 May 2010 (UTC)

Gold(III) chloride[edit]

Hi Tetracube

I respectfully disagree with your reorganization [1] as I find that structure and preparation are two distinct threads. --Rifleman 82 (talk) 19:14, 22 May 2010 (UTC)

Feel free to break them up again. The only reason I merged them was because the GA review complained that the synthesis section was too short - but can that be helped if the synthesis really is just that simple?—Tetracube (talk) 19:26, 22 May 2010 (UTC)

I see.... well it really seems to be that simple. I've rearranged it to be more aligned with WP:CHEMMOS, please take a look. --Rifleman 82 (talk) 22:11, 22 May 2010 (UTC)

Pronunciation[edit]

Good job! Thanks! --Rifleman 82 (talk) 04:37, 28 May 2010 (UTC)

You're welcome.—Tetracube (talk) 05:12, 28 May 2010 (UTC)

Your recent edit to caesium[edit]

I noticed that you reverted a good faith edit by an anonymous editor. He clarified it, because it could be construed by the current revision that some elements with more than one stable isotope are less electronegative than caesium. His revision stated that it was the least electronegative stable element, which has only one isotope BTW. This is just my opinion. --Chemicalinterest (talk) 18:25, 1 June 2010 (UTC)

I thought it was the anon's revision that had this ambiguity. The current revision reads "It is the least electronegative element that has stable isotopes, of which it has only one, caesium-133." -- i.e., it is the least electronegative element with stable isotopes, and BTW it has only one stable isotope. The anon's revision read "It is the least electronegative element that has only one stable isotope, caesium-133." -- which could be misconstrued as it (caesium) being the least electronegative among those elements that have only one stable isotope, implying that there may be less electronegative elements that have more than one stable isotope.—Tetracube (talk) 18:49, 1 June 2010 (UTC)

Template[edit]

I´m sorry, it was not my intention to do it. I was rewriting the history of the sulphuric acid and maybe I accidentally deleted the template. Thanks for the advice, and I promiss it won´t happen again.I´ll reinsert the information but keep the template--Knight1993 (talk) 20:45, 12 June 2010 (UTC)

External links added by User:Jsv3[edit]

Hi Tetracube. IMHO it was wrong to revert all addition of an external link to a page on the website of the Agency for Toxic Substances and Disease Registry as spam. On WP:EL I do not find any reason against e.g. the addition in Ethion or Disulfoton. I see, however, that in articles already containing many external links, such mass additions are useless. I would appreciate if you could re-think your reverts yourself and maybe explain to this new user, where the addition of external links makes sense and where it does not. --Leyo 22:10, 14 June 2010 (UTC)

Chromite (compound)[edit]

Thank you for your quick work on chromite. I just need to find a formula for chromites; I also posted a post at WP:Chemistry. --Chemicalinterest (talk) 17:56, 15 June 2010 (UTC)

You are now a Reviewer[edit]

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Hello. Your account has been granted the "reviewer" userright, allowing you to review other users' edits on certain flagged pages. Pending changes, also known as flagged protection, is currently undergoing a two-month trial scheduled to end 15 August 2010.

Reviewers can review edits made by users who are not autoconfirmed to articles placed under pending changes. Pending changes is applied to only a small number of articles, similarly to how semi-protection is applied but in a more controlled way for the trial. The list of articles with pending changes awaiting review is located at Special:OldReviewedPages.

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If you do not want this userright, you may ask any administrator to remove it for you at any time. Courcelles (talk) 18:04, 18 June 2010 (UTC)

Tetrahedral molecular geometry ‎[edit]

It's not necessarily vandalism. 109.5° is near 109° 28′, which could have been what was intended. The exact value seems to be 109° 28′ 16.394″ , or 109.47122°. — Arthur Rubin (talk) 21:06, 9 July 2010 (UTC)

Mea culpa. Thanks for pointing it out. I guess I was a bit too trigger-happy there. :-( It didn't even occur to me that that might have been what was intended.—Tetracube (talk) 03:15, 10 July 2010 (UTC)

Abstract polytopes[edit]

You have previously contributed to the Abstract polytope article. If you feel able, please contribute to the discussion on Notation, where I am hoping to resolve a long-standing dispute. Many thanks in anticipation. — Cheers, Steelpillow (Talk) 14:47, 17 July 2010 (UTC)

24-cell coordinates[edit]

Hi Tetracube,

I added a summary coordinate table for 24-cell family at: Uniform_polychoron#Coordinates_3. I changed the format a bit, split sqrt(2) terms to a second vector.

First I'm wondering how you derived these? The hypercube family is much nicer, readable from the CD diagram. I wondered if there's any better representation that makes the derivation more obvious?

ALSO, I'm curious if you ever looked at the demihypercube family. For 4D, there's no new uniform polytopes, but there are new ones at 5D and higher, and it would nice to have simple coordinates for them, if you wanted a challenge.

And if you're really interested in a challenge sometime, perhaps look at the E6,E7,E8 families - simple coordinates in 8-space. For E8 I derived a few by brute search from the 4_21 polytope coordinates, like 1_42_polytope and 2_41_polytope. And there's 3_21_polytope in 7D with coordinates from Coxeter. I don't have any for E6 polytopes.

Maybe you've noticed I've been doing n-simplex uniform truncations with (Coxeter plane) graphs using the simple coordinates from hypercube diagonal faces, like 5-simplex#Related_uniform_5-polytopes.

Thanks for any help! Tom Ruen (talk) 23:05, 21 September 2010 (UTC)

Sorry for this late, late reply. I've been inactive on Wikipedia for a while now.
Some of the 24-cell family coordinates are quite easy, because they coincide with tesseract/16-cell family members. There are a few that aren't; these I derived by hand. There are a couple that can be derived by taking one of the coincidental tesseract family coordinates and expanding the axial cells forward (in the sense of Alicia Boole) by an amount calculated to yield uniform edge lengths in the corner facts. These may require additional points to fully cover all the vertices in the corner facets, which are found by examining the 2D projection of the polytope and carefully extrapolating back to 4D and confirmed by running the resulting points through my polytope viewer and verifying the number and shape of the resulting cells (including edge lengths, distances, etc.).
The hardest to derive was the omnitruncated 24-cell, which required three points, not merely the two that I was expecting. (I didn't realize this until much later.) Extrapolating from 2D diagrams did not help, partly because it wasn't obvious that 3 points were needed, and partly because 2D diagrams simply do not have enough information to reliably derive the right coordinates. One of the points I had was wrong due to such a miscalculation, and was consistently yielding a strange number of facets with the wrong shapes, non-uniform edge lengths, and redundant points from the LP solver used to derive the facets. In the end, I finally obtained the right coordinates by taking the one point that I was absolutely sure about, and multiplying it (by hand!) by a double-rotation matrix derived from 24-cell symmetry, that maps the point outside of the tesseractic symmetry's all-permutations-and-changes-of-sign (APACS) set. Doing this revealed the miscalculated point, and another multiplication yielded the 3rd point. The coordinates were confirmed by the output from the polytope viewer, which you can see on omnitruncated 24-cell, as well as the cell counts, edge lengths, and cell shapes.
This little ordeal gave me high confidence in these coordinates, because I saw how even a slight miscalculation would completely screw up the resulting polytope in a very obvious way. Because I'm using the tesseractic APACS algorithm to generate the points from a few base points, for the corner facets of the omnitruncated 24-cell (mostly covered by the matrix transformed points) to turn out with exactly the same shape as the axial facets (generated by the tesseractic points) gives very strong confidence that the coordinates are correct. Other evidence such as the shapes of the hexagonal prisms also give very strong confidence, since they come in such large numbers and variety of orientations that if any of the base points were wrong, it would be very visible.
As for the demihypercubes and the Gosset polytopes, I may attempt those some day when I figure out how to deal with these things with alternating permutations. :-) After the difficulty I had with the omnitruncated 24-cell, I gave up after a few attempts to algebraically derive coordinates for members of the 120-cell family, and instead settled for programmatic truncations from the 120-cell and 600-cell coordinates given by Coxeter. But you never know—one of these days, I might actually algebraically figure out the coordinates of the omnitruncated 120-cell, which I still don't have. That may give me the necessary inspiration to tackle the Gosset polytopes. :-)—Tetracube (talk) 23:57, 19 October 2010 (UTC)
Thanks for the reply, and your great past work. I've made good use of it, making lots of family Coxeter plane projection graphs, like User:Tomruen/temp4. Tom Ruen (talk) 00:16, 20 October 2010 (UTC)

Dk family polytope coordinates[edit]

Hi Tetracube - I think I've deduced the coordinates for all the Dk family polytopes, tested on D3,D4, writen up at User_talk:Tomruen#Deriving_coordinates_from_Coxeter-Dynkin_diagrams. Tom Ruen (talk) 18:50, 20 November 2010 (UTC)

24-cell family coordinates[edit]

Hi Tetracube. I tried to inductively expand the 24-cell family coordinates from both symmetry direction. It looked like the lower 2 mirrors and upper to mirrors (around the 4) worked as two different points (like Bk family), although I don't follow the generation pattern exactly. Can you take a look and see if it makes sense? I've not tried computing with them yet. User:Tomruen/temp2 Tom Ruen (talk) 06:47, 29 November 2010 (UTC)

Tested - looks good, table of graphs at User:Tomruen/temp3. Interestingly my B3 graphs were on different planes on the dual pairs, so really there's a B4a, B4b Coxeter planes, based on the octahedral cell orentations of the two 24-cells. I'll copy to uniform polychoron when I get that sorted out. Tom Ruen (talk) 01:49, 30 November 2010 (UTC)

Very pretty: (thanks to your coordinates) Tom Ruen (talk) 02:37, 30 November 2010 (UTC)

Name 24-cell truncated 24-cell snub 24-cell rectified 24-cell cantellated 24-cell bitruncated 24-cell cantitruncated 24-cell runcinated 24-cell runcitruncated 24-cell omnitruncated 24-cell
Schläfli
symbol
{3,4,3} t0,1{3,4,3}
t{3,4,3}
s{3,4,3} t1{3,4,3}
r{3,4,3}
t0,2{3,4,3}
rr{3,4,3}
t1,2{3,4,3}
2t{3,4,3}
t0,1,2{3,4,3}
tr{3,4,3}
t0,3{3,4,3} t0,1,3{3,4,3} t0,1,2,3{3,4,3}
Coxeter
diagram
CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node h.pngCDel 3.pngCDel node h.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node.png CDel node 1.pngCDel 3.pngCDel node.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node.pngCDel 3.pngCDel node 1.png CDel node 1.pngCDel 3.pngCDel node 1.pngCDel 4.pngCDel node 1.pngCDel 3.pngCDel node 1.png
Schlegel
diagram
Schlegel wireframe 24-cell.png Schlegel half-solid truncated 24-cell.png Schlegel half-solid alternated cantitruncated 16-cell.png Schlegel half-solid cantellated 16-cell.png Cantel 24cell1.png Bitruncated 24-cell Schlegel halfsolid.png Cantitruncated 24-cell schlegel halfsolid.png Runcinated 24-cell Schlegel halfsolid.png Runcitruncated 24-cell.png Omnitruncated 24-cell.png
F4 24-cell t0 F4.svg 24-cell t01 F4.svg 24-cell h01 F4.svg 24-cell t1 F4.svg 24-cell t02 F4.svg 24-cell t12 F4.svg 24-cell t012 F4.svg 24-cell t03 F4.svg 24-cell t013 F4.svg 24-cell t0123 F4.svg
B4 24-cell t0 B4.svg 24-cell t01 B4.svg 24-cell h01 B4.svg 24-cell t1 B4.svg 24-cell t02 B4.svg 24-cell t12 B4.svg 24-cell t012 B4.svg 24-cell t03 B4.svg 24-cell t013 B4.svg 24-cell t0123 B4.svg
B3(a) 24-cell t0 B3.svg 24-cell t01 B3.svg 24-cell h01 B3.svg 24-cell t1 B3.svg 24-cell t02 B3.svg 24-cell t12 B3.svg 24-cell t012 B3.svg 24-cell t03 B3.svg 24-cell t013 B3.svg 24-cell t0123 B3.svg
B3(b) 24-cell t3 B3.svg 24-cell t23 B3.svg 24-cell t2 B3.svg 24-cell t13 B3.svg 24-cell t123 B3.svg 24-cell t023 B3.svg
B2 24-cell t0 B2.svg 24-cell t01 B2.svg 24-cell h01 B2.svg 24-cell t1 B2.svg 24-cell t02 B2.svg 24-cell t12 B2.svg 24-cell t012 B2.svg 24-cell t03 B2.svg 24-cell t013 B2.svg 24-cell t0123 B2.svg

New 4D Animations[edit]

Hey TC, I'm finally getting around to rendering some new animations. Clifford torus was the first, but I may be able to finally do the 120-cell and 600-cell, along with truncated/snub versions of some of those. In fact, I should be able to render anything that I can get my hands on a VEF file for. Any recommendations/sources I should check out? JasonHise (talk) 08:58, 3 February 2011 (UTC)

Coordinates for many of the uniform polychora are defined, like Uniform_polychoron#Coordinates for the 5-cell family. So you just generate all the coordinate permutations, then find edges by equal lengths, and another search for face planes by pairs of adjacent edges. I've just been using the this to generate 2D special orthogonal symmetry projections, VE only, so haven't been tracking faces. Tom Ruen (talk) 05:59, 7 February 2011 (UTC)
It appears that the permutations are typically embedded in an arbitrary hyperplane in 5-space... I am imagining that to convert these to 4D coordinates I will need to use 5 of the points to solve for a transformation matrix that will rotate/translate all of the points from [x, y, z, w, v] to [x, y, z, w, 0]? JasonHise (talk) 07:07, 7 February 2011 (UTC)
Sorry for such a late reply; I have been quite inactive on Wikipedia. For converting 5-space coordinates into 4-space in a nice, symmetric manner, check out User:Tetracube/Coordinates_of_uniform_polytopes#Mapping_coordinates_back_to_n-space. Don't worry if the matrix looks scary; the pattern is actually quite simple to implement in code.—Tetracube (talk) 05:35, 22 April 2011 (UTC)
True. The n-simplices are represented as facets of the (n+1)-hypercubes, so you need to pull out a hyperplane local coordinates for easier transformations. Tetracube computed some explicitly, like Cantellated_5-cell#Coordinates but surely simpler to do computationally. (I didn't bother in my graphs because I was just showing a single orthogonal plane projection) The hyperplane normal vector ought to just be (1,1,1,1,1) I think, so any basis will do that is orthogonal to that. Tom Ruen (talk) 09:04, 7 February 2011 (UTC)

Pronunciation of "iron"[edit]

Please note in future that the UK pronunciation of "iron" has no /r/. "Ion" and "iron" are homophones in RP.

46.115.1.226 (talk) 10:30, 22 April 2011 (UTC)

Supercubes[edit]

I recently picked up supercube stickers for my 3×3×3, 4×4×4 and 5×5×5 cubes and it occurred to me that the relevant permutation sections don't list the increased possibilities that result. Computing them is simple enough, but I'd like a second opinion as to whether they're necessary.

I also thought about using the "hidden" template so that the unabridged numbers only show up if a person clicks "show." Hellbus (talk) 22:35, 23 May 2011 (UTC)

Sounds like a good idea. I believe the "supercube" stickers correspond with the full permutation group of the NxNxN cubes (the odd/even parity of the face centers in the regular coloring scheme is due to some positions being indistinguishible, thus effectively collapsing it to a subgroup of the full group); so in that sense, it is something worth noting.—Tetracube (talk) 22:58, 23 May 2011 (UTC)

I think I have the parity restrictions on the 4×4×4 and 5×5×5 supercubes figured out. The 3×3×3 supercube permutations are already in that article.

On the 4×4×4 the center parity is unaffected by the edge parity, but is affected by corner parity. Turning an inner slice causes an odd permutation of the edges and an even permutation of the centers. Turning an outer slice causes odd permutations of the corners and centers and an even permutation of the edges. Thus, the corner and edge permutations remain the same, while the center permutations go from 24!/4!6 to 24!/2.

The 5×5×5 has a greater number of restrictions. The fixed center parity is the same as the 3×3×3. The edge-center parity is tied to the outer edges. Turning an inner (but not central) slice causes an odd permutation of the edge-centers and outer edges and an even permutation of the corner-centers. Although it is possible to swap two middle edges and two corners, it does not appear to be possible to swap two edge-centers and two corner-centers with the rest of the cube solved. An odd permutation of the corner-centers only occurs if the fixed centers have an odd number of 90-degree twists. Thus, the permutations of each set go from 24!/4!6 to 24!/2, with the total being the square of the latter figure.

Clear as mud? :) Hellbus (talk) 23:08, 1 June 2011 (UTC)

Actually, the 4x4x4 has the same restrictions as the 5x5x5, the only difference is that due to the lack of fixed face centers, some of the distinct permutations are visually identical. To understand this, just imagine that the internal mechanism, the 6-armed spider (to use the V-cube's mechanism as an example), has each arm labelled with the color the corresponding face is "supposed" to have (i.e., the color on that face when the cube was assembled at the factory). But since you can't see the internal mechanism, after scrambling and solving you may have ended up with a configuration which corresponds, say, with the original rotated by 180°. If you labelled the internal arms, you'll see that the colors actually don't match the original configuration, but since the internal arms are not visible, the outside looks perfectly solved. In other words, some of the permutations which are mathematically distinct are visually identical, so the number of possibilities is reduced.
When you turn an inner slice on the 4x4x4, actually there is an odd permutation of both the edge pieces and the face centers (the edge pieces cycle in a cycle of 4, which means 3 swaps, i.e., odd; similarly, each pair of face centers in the slice are cycled in a cycle of 4, that is, 3 swaps, i.e., odd). The bottom line is, odd permutations in one of the face centers, edges or corners must be matched by an odd permutation in another group. In other words, every twist has an even permutation, but it can be composed of two even permutations of the underlying pieces, or two odd permutations. E.g., it's possible to swap two corners but only if you also swap two edge pairs. It's possible to swap two face centers, but only if you also flip an edge pair. (It's possible to flip an edge pair without visually touching anything else only because two face centers with the same color can swap without changing the appearance of the cube, so the matching odd permutation sorta "hides" itself in there.)—Tetracube (talk) 04:02, 2 June 2011 (UTC)

Question about someone undoing my article edit[edit]

Hi Tetracube, thanks for the welcome. I have a question.

Two days ago I added a neutral statement to the page of The Grasshopper Company. I added, "Grasshopper Mowers became a national advertiser on the Rush Limbaugh radio program during the large sponsor exodus following the Sandra Fluke controversy." I went to look at the page today and my edit has been undone by user Msimmon201.

It's possible Msimmon201 is associated with the company and doesn't like this piece of information being publicized, but it is a simple truth presented in a factual and neutral way. What can/should I do about his/her undoing of my edit? I do not wish to start an edit war but I see no reason why Msimmon201 should be allowed to undo my edit. Gilajones (talk) 00:14, 26 March 2012 (UTC)

Hi Gilajones, I didn't remember sending you a welcome message, but I went to your talk page and saw that it was 5 years ago. Anyway. About your question, do you have a reliable citation for your statement? If you have a solid reference to a reputable source, then by all means reinstate your edit. If you get reverted again, you can try to contact that editor and work it out with them. Start a discussion on the article's talk page to see if you can garner consensus from other editors who are also editing that page. If all else fails, you can try to get arbitration. But first and foremost, to have any case at all, you need to make sure your statement is backed up by a solid reference from a reputable source (see WP:Citing sources for more information). Hope this helps.—Tetracube (talk) 00:36, 26 March 2012 (UTC)

Thank you very much for the info and for taking your time to help me. Gilajones (talk) 15:53, 27 March 2012 (UTC)

AX11E0[edit]

You mentioned once that the structure of AX11E0 is an octadecahedron. What does this octadecahedron look like? Double sharp (talk) 06:27, 7 May 2012 (UTC)

Needing Wiki contribution assistance![edit]

Greetings Tetracube,

I am looking for an experienced Wikipedian to contribute an article for our band Mr. Meeble. I have checked and we meet the Wikipedia "notability" guidelines for a band. We have a very basic Wikipedia article written already, but I know that someone like yourself may be able to point out our formatting errors and critical omissions. You can hear our music and see our videos here:

http://youtube.com/mrmeeble
http://soundcloud.com/meeble

Let me know if you would be willing to help!

Regards,
Devin
mm @ meeble.com

Devbot (talk) 03:33, 12 June 2012 (UTC)

Shengshou cubes[edit]

Thoughts on including sections and articles on these? On the one hand their designs clearly copy heavily from the V-Cube patent, but on the other hand theirs are the only 8- and 9-layer cubes widely available. They also make 6- and 7-layer cubes and my initial impression from the ones I have is that they actually improve somewhat on the V-Cube design. I can calculate the permutations for the 8 and 9 easily enough, though I'd have a hard time finding a reference for it. Also, nearly every review I've read of these puzzles has been in the form of a Youtube video, which is also in a bit of a gray area with regard to reference usability. The 6 and 7 layer cubes could go in as sections in the V-Cube 6 and V-Cube 7 articles, respectively. Thoughts? Hellbus (talk) 03:05, 20 February 2013 (UTC)

These are somewhat controversial, because they are believed to be infringing on the V-cube patents. So it may be hard to write it from a NPOV. And yeah, I don't know if youtube constitutes as a reliable source -- likely not.—Tetracube (talk) 05:54, 20 February 2013 (UTC)

Since did i vandalise anything?? what are you on about? — Preceding unsigned comment added by 119.224.47.57 (talk) 02:57, 10 November 2013 (UTC)