Talk:Rubik's Cube/Archive 4

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Brute force algorithm?

Do you think it would be impracticable to solve the Rubik's cube on a standard 1.x Ghz machine by a brute force recursive algorithm? See User:Tisane/Rubik's cube saga Tisane (talk) 12:14, 21 February 2010 (UTC)

Two basic problems combine to make this impractical. First, the number of possible positions is 43,252,003,274,489,856,000. Assuming, say, 200 cycles per position (and that's assuming a VERY efficient program, way more that PHP could ever produce), you can do 5,000,000 positions per second. So you're looking at 8650400654897.9712 seconds to look at every possible combination. That's over 274,000 years.

But wait, it gets worse. As anyone can tell you, it's very easy to repeat yourself when solving a cube. Wildly different series of moves can lead to the same result. So, to avoid this, you need to maintain a table of all the positions you've already looked at so you don't loop back on yourself. Assuming one bit per position, that's 5406500409311232000 bytes. That's just under 5035195881 Gigabytes of RAM. It has to be RAM, because you don't have time to check the hard drive for each position as you go . What was your budget for this project?

These two issues just scratch the surface of the problem, by the way. The path solving issues by themselves are extremely complex. - Richfife (talk) 18:26, 21 February 2010 (UTC)

Conjugacy classes

How many conjugacy classes has the Rubik's cube group? --84.61.131.18 (talk) 07:56, 15 July 2010 (UTC)

1x1x1 cube

Shouldn't this article also explain that there exists a novelty 1x1x1 Rubik's Cube? [1][2][3]

76.66.193.119 (talk) 11:27, 4 August 2010 (UTC)

If I were you, I'd add it to the politics section of Rubik's Cube in popular culture and rename the section if that floats your boat. - Richfife (talk) 19:22, 4 August 2010 (UTC)

Jargon in the Solutions section

I am a Rubik's noob, and I don't understand many of the terms in the Solutions section. None of these terms are defined anywhere in the article. Many of you probably know what these mean, but a regular Rubik's noob like me certainly doesn't. Undefined terms include:

• Middle layer, as in: "ƒ (Front two layers): the side facing you and the corresponding middle layer"
• Orienting, as in: "This is then followed by orienting the last layer then permuting the last layer..."
• Permuting, as seen above
• The cross, as in: "The cross is done first followed by first-layer corners and second layer edges simultaneously"
• First-layer corners, as seen above
• Second-layer edges, as seen above

SnottyWong ^converse 23:29, 6 August 2010 (UTC)

I can explain the middle layer and the cross but the others I can not explain very well. When holding the cube the middle layer is the layer in the middle. The cross is when you have the first layer edges solved and nothing else.Sumsum2010 · Talk · Contributions 19:23, 7 August 2010 (UTC)

Manufacturing and assembly

Interesting material about the manufacturing and assembly process for Rubik's cube:

http://www.encyclopedia.com/doc/1G2-2897100076.html

The same material has been reproduced on various websites without attribution (Google for "Katzenjammer and the Mayblox" [with quoutes] and select "with the omitted results included" to see a bunch of them. According to encyclopedia.com the copyright is:

COPYRIGHT 1996 Gale Research Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group.

...so it should not be included as is, but rather be either referenced or used as a guide while improving the page. Guy Macon 16:52, 1 September 2010 (UTC)

11x11 Cubes

I just want to weigh in on this because the edits are rolling in.

1) If you pay attention to the demonstration videos of the 11x11 cube, you will note a curious thing: They only turn the cube on a single axis. The guy flips it around a lot and makes a lot of quick moves, but all of the twists are along the red/orange axis. It's not at all clear that what we're seeing isn't 11 plates around a single axle dressed up to look like a functional cube.

2) (Not really important from a Wikipedia standpoint, but still...) The 11x11 cube violates V-Cubes patents.

Thanks! - Richfife (talk) 20:00, 1 March 2010 (UTC)

I'm pretty sure the 11x11x11 is fully functional. But, in addition, a 12x12x12 is available too... not infringing any copyrights... http://www.bedardpuzzles.com/index.php?puzzle/49 173.168.177.217 (talk) 18:40, 20 March 2010 (UTC)

Here you can buy 11x11x11 cubes: http://www.dealextreme.com/details.dx/sku.49212 here you can see it solved: http://www.youtube.com/watch?v=hOilnrGrKsY and here taken apart: http://www.youtube.com/watch?v=0-mf3OYeg8c —Preceding unsigned comment added by 212.78.165.203 (talk) 14:10, 26 October 2010 (UTC)

Math check: permutations

Could someone else double-check the math in the Permutations section? It as recently edited by an IP address with no other edits, and I would like to confirm what I think the proper formula is. Thanks! Guy Macon 20:50, 6 December 2010 (UTC)

Yep, it's a valid edit from an IP. It had to happen eventually... - Richfife (talk) 02:10, 7 December 2010 (UTC)

when was it first solved

was it solvable when first manufactured? — Preceding unsigned comment added by Arkelweis (talk • contribs) 14:23, 26 December 2010 (UTC)

Operating on the assumption that this isn't a troll question, Rubik's cubes have always been solvable at the very least by reversing whatever operations have been performed on them. - Richfife (talk) 15:50, 26 December 2010 (UTC)

The first person to solve a scrambled cube was Ernő Rubik. He wrote "It was wonderful, to see how, after only a few turns, the colors became mixed, apparently in random fashion. It was tremendously satisfying to watch this color parade. Like after a nice walk when you have seen many lovely sights you decide to go home, after a while I decided it was time to go home, let us put the cubes back in order. And it was at that moment that I came face to face with the Big Challenge: What is the way home?" Within a month he could solve a scrambled cube. What I would like to know (and it would be a great addition to this page if properly cited) is how long it took him to solve each cube once he had figured out how. Guy Macon 17:49, 26 December 2010 (UTC)

References Needed on Permutations Section?

There's a tag that says that references are needed on the permutaions section, but I don't know what one would reference. It's all just math and there isn't anything that I think needs to be cited. I think the tag should be removed. Any opinions? Nathan Wonnacott (talk) —Preceding undated comment added 19:44, 31 December 2010 (UTC).

That is exactly the kind of thing that should be referenced. SpinningSpark 22:55, 31 December 2010 (UTC)

Done. Please double check my work. Thanks! Guy Macon 00:09, 19 January 2011 (UTC)

Semi-protection from Vandalism?

Does anyone think that the ongoing vandalism of this page merits asking for semi-protection? See WP:PROTECT#Semi-protection and WP:ROUGH for guidelines. In particular, are any constructive edits being made to the page from users who would be blocked by semi-protection? Guy Macon 18:05, 14 January 2011 (UTC)

The rate of vandalism looks a bit slow to require semi-protection at this time. But if it keeps up or intensifies there's no harm in asking at Requests for page protection. Siawase (talk) 18:13, 14 January 2011 (UTC)

It certainly has a history of it. There's only been one positive IP edit that I'm aware of (math correction). Time for something more permanent? - Richfife (talk) 18:16, 14 January 2011 (UTC)

My peronal criteria for long term protection are:

• The article gets hit on average at least once a day over a one month period
• At least two-thirds (ideally 90%) of the watchlist is vandalism and the cleanup afterwards
• There are no significant IP contributors to the article.

If someone wants to do the stats on the watchlist I will consider it, but from a brief glance I would agree with Siawase that it is currently too slow to justify. SpinningSpark 18:45, 18 January 2011 (UTC)

I have requested semi-protection for the article. Bulldog73 (talk) 19:16, 19 February 2011 (UTC)

Semiprotection is now in place (click on the padlock icon on the main page for details). This should reduce the annoyance of having to revert vandals here on an almost-daily basis. Guy Macon 22:13, 19 February 2011 (UTC)

ideal toy?

ideal toy or ideal toys? —Preceding unsigned comment added by 94.248.136.240 (talk) 02:25, 26 February 2011 (UTC)

Good catch! It's Ideal Toy Corp., so I fixed it and left a note at Talk:Ideal Toy Company to discuss renaming that page. Guy Macon 17:02, 26 February 2011 (UTC)

I don't think you needed to place "Corp." after every mention of Ideal, just the first occurence would do. They are normally referred to as Ideal Toys in the same way the Ford Motor Company is thereafter just called "Ford", even in its own article. Also, are you sure they were not still the Ideal Toy Company at the time of the Rubik Cube launch? SpinningSpark 19:08, 26 February 2011 (UTC)

Changed the latter mentions to "Ideal." Good idea.

It was Ideal Novelty and Toy Company until the 1930's but I have yet to find any evidence evidence that the name was ever Ideal Toy Company. I am still researching this, but I suspect that it went directly from Ideal Novelty and Toy Company to Ideal Toy Corporation. See http://tess2.uspto.gov/bin/showfield?f=doc&state=4003:tcp6oq.2.5 for an example of them using that name in 1962, which predates the Rubik's Cube. When I get a finall answer (see the Ideal page for more info) I will come back and edit this page if needed.) Guy Macon 20:33, 26 February 2011 (UTC)

Record update

seems there is a new record http://www.youtube.com/watch?v=wIvHw17vuGU 70.109.218.58 (talk) 05:46, 8 May 2011 (UTC)

Spelling of "centre"

There's eight "centre"s and three "center"s (not counting one in the title of a reference)—needs fixing. "Colour"'s consistent, though! 86.28.121.200 (talk) 21:23, 2 June 2011 (UTC)

 Done, changed the 'center's to 'centre's. Thanks! Samwb123^T-C-E 03:28, 3 June 2011 (UTC)

Suggestions for the introduction

Hi - I am the owner of Seven Towns and as such have company information on sales and licensing information and overall control of the Rubik Intellectual property rights. I would like to suggest that the brief introduction (as rewritten below) should mention Tom Kremer (my father) and Seven Towns as that is key to understanding how the Cube arrived in the West and the fact that the Rubik Cube intellectual property is not in the public domain and that Erno Rubik is still involved in the intellectual property:

Rubik's Cube Introduction

The Rubik's Cube is a 3-D mechanical puzzle invented in 1974[1] by Hungarian sculptor and professor of architecture Ernő Rubik. Originally called the "Magic Cube",[2] the puzzle was first introduced to the Hungarian toy market by Politoys in 1977. All international rights were controlled by a Hungarian Government appointed consumer trading agency called Consumex. Tom Kremer (a toy inventor himself and owner of Seven Towns Ltd) brokered a deal between Consumex and Ideal Toys that allowed Ideal to sell the Cube internationally and they launched "The Rubik's Cube" at the US January toy fair in 1980. The Rubik Cube won numerous accolades including the German Game of the Year special award for Best Puzzle that year. The Cube became a world-wide phenomenon selling around 300 million units and spawning many published solution books. [3] Seven Towns gradually acquired all the rights in the 1980’s starting in 1984 with those held by Ideal when they withdrew from the toy industry. Seven Towns continues to hold all international rights, and has invested in Trademark and other intellectual property protection and to share the income derived from those rights with Erno Rubik and his family. As of January 2009, 350 million cubes have sold worldwide[4][5] making it the world's top-selling puzzle game.[6][7] It is widely considered to be the world's best-selling toy.[8] In a classic 3x3 Rubik's Cube, each of the six faces is covered by nine stickers, among six solid colours (traditionally white, red, blue, orange, green, and yellow).[9] A pivot mechanism enables each face to turn independently, thus mixing up the colours. For the puzzle to be solved, each face must be a solid colour. Similar puzzles have now been produced with various numbers of stickers, not all of them by Rubik. The original 3×3×3 version celebrates its thirtieth anniversary in 2010.

DavidKremer (talk) 09:25, 7 October 2010 (UTC)

Hi David. I have found some reliable sources which are independent of the company which verifies this information:

1. this ariticle from the Montreal Gazette

   Interesting an American manufacturer in the cube became the task of Thomas Kremer, a Transylvanian by birth who heads a British company called 7 Towns Ltd. Kremer saw the cube at the Nuremberg Toy Fair and afreed to act as its representative.

2. here is an article in the Russian Membrana:

   Воспользовавшись удобной ситуацией, в 1985 году кремеровская фирма Seven Towns перекупает права на кубик и к 1991 году очень осторожно и выборочно начинает вновь потихоньку выпускать его на рынок.

   • GTranslate: Taking advantage of a convenient situation in 1985 kremerovskaya firm Seven Towns outbids right to block, and by 1991 very carefully and selectively start again slowly releasing it to market.

3. this is an article in the Vietnamese VnExpress:

   Mặc dù khối Rubik rất được ưa chuộng ở Hungary, tình trạng đối đầu về chính trị vào thời bấy giờ khiến nó không thể sang Mỹ. Hai người khiến Rubik trở thành thứ đồ chơi nổi tiếng toàn cầu là Laczi Tibor và Tom Kremer - chủ công ty Seven Towns Ltd tại London. Họ đã mua được quyền phân phối Rubik trên phạm vi thế giới. Tibor đã thuyết phục được giới chức Hungary cho phép đưa công nghệ sản xuất khối Rubik ra khỏi nước này. Trong khi đó, Kremer tìm thấy một công ty đồ chơi Mỹ có tên Ideal Toy sẵn sàng tiếp thị và phân phối sản phẩm.

   • GTranslate: Although volumes are very popular Rubik in Hungary, the situation of political confrontation at that time made it impossible to America. Two people made toy Rubik became famous worldwide as Laczi Tibor and Tom Kremer - owner of Seven Towns Ltd. in London. They bought the distribution rights throughout the world Rubik. Tibor had persuaded officials to allow Hungary to mass production technologies Rubik out of the country. Meanwhile, Kremer found an American toy company called Ideal Toy ready marketing and product distribution..

Other sources are:

1. Timeless toys: classic toys and the playmakers who created them By Tim Walsh
2. New Scientist Dec 24-31, 1987
3. ... and there are probably more!

I'll leave it for others to add this information as required. -- PhantomSteve/talk|contribs\ 14:50, 7 October 2010 (UTC)

I'm not sure all of that should go into the lede, but I'll look at it when I have a longer contiguous chunk of time. - Richfife (talk) 16:59, 7 October 2010 (UTC)

Maybe I am missing something, but I find the suggested intro to be yawn-inducing. I am interested in the maths of the cube, and in how Rubik came to invent it. I do not care a fig for what business man got to distribute it in the shops, any more than I wish to know which check out chicks scan the bar code on the Cubes when they sell them. No disrespect to your old man, but if what he did is a notable contribution to story of the Cube, than I suppose he should be identified and noted with every toy, gadget and gizmo he has ever peddled to the public, and frankly, I just can't see anyone giving a flying turd. Myles325a (talk) 06:52, 3 June 2011 (UTC)

Counting of individual cubes

The number of individual cubes that compose a cube of side size n is:

n^3 - (n-2)^3

Perhaps this equation should be added to the article. — Preceding unsigned comment added by Wrameerez (talk • contribs) 23:12, 2 June 2011 (UTC)

The cubic terms cancel out in this expression. This is because the puzzle is only interested in cubies on the surface, hence it is a square law in reality. SpinningSpark 09:22, 3 June 2011 (UTC)

How to disassemble

I would have changed this directly, but this page is protected? In machanics section it says that:

The Cube can be taken apart without much difficulty, typically by rotating the top layer by 45° [...]

It's not 45°, but less than that, I think it's 40° or so (could be measured). 45° is wrong. It doesn't break open if you rotate 45°. It should be rotated as in the first image. You align that lines, and it falls open. At 45°, it doesn't get open that easy. — Preceding unsigned comment added by 95.248.76.198 (talk) 11:03, 6 June 2011 (UTC)

Number of orientations of centres

Of the $4^{6}$ possible orientations of face centres that can be achieved when disassembly of a cube is permitted, it is my understanding that only one quarter of the $4^{6}$ orientations are achievable when disassembly is prohibited. In particular, it is my understanding that if one correctly orients five of the six centres then the sixth centre will necessarily be correctly oriented. The article currently indicates that one half of the $4^{6}$ orientations are achievable, as if it were possible that we could have five correctly oriented centres with the sixth centre 180° out of orientation. But this is not possible without disassembly, right? If you disagree, what is your algorithm for rotating a centre 180° without changing the arrangement or orientation of any other face? —Quantling (talk | contribs) 16:53, 30 June 2011 (UTC)

Never mind. I figured out the algorithm. —Quantling (talk | contribs) 18:00, 30 June 2011 (UTC)

"Philip Marshall's The Ultimate Solution to Rubik's Cube"

It appears Marshall's method only works on 2x2x2 cube's... I can't find a 2-algorithm solution for the 3x3x3 cube. MrJosiahT (talk) 03:27, 25 July 2011 (UTC)

Picture

The picture of the cube at the beginning of this article is not possible. No corner-piece on the original cube features the colors red, white and blue. When in the solved state, white and blue are on opposite sides of the cube. — Preceding unsigned comment added by Liskow (talk • contribs) 14:01, 4 July 2011 (UTC)

On the one hand, the color order is not canonical. They can appear anywhere they're put. On the other hand... Even discounting that, the picture is still impossible. The three visible center pieces are red, green and yellow. Which means that the red, white and blue corner piece must go to the bottom left. Which means that white is opposite green and blue is opposite yellow. But there are pieces with both blue and yellow on them. Oopsy... Part of me says "so what?" but part of me know that it's going to bug the hell out of me and a lot of other people going forward. I've never edited an svg file before, but I'll give it a shot. - Richfife (talk) 15:06, 4 July 2011 (UTC)

The visible centre pieces are orange, green and yellow, not red, green and yellow. The red, white and blue corner piece therefore belongs on the diametrically opposite corner, not the lower left and the puzzle is doable...unless you can find another flaw! SpinningSpark 12:54, 6 August 2011 (UTC)

You're right. I was able to match the picture with a standard Rubik's Cube (I took a picture, but I haven't had a chance to get it off the camera). Sooo... As Emily Litella said... "Never Mind". - Richfife (talk) 14:44, 6 August 2011 (UTC)

Anniversary inaccuracy?

The opening line states that "[the] Rubik's Cube is a 3-D mechanical puzzle invented in 1974" and that the "original 3×3×3 version celebrated its thirtieth anniversary in 2010." Surely that would have been the 36th anniversary?41.160.161.117 (talk) 10:55, 12 August 2011 (UTC)

I believe the anniversary was intended to be of the cube's first release in the US (The only country that matters (sarcasm)). Still, it could use some clarity. - Richfife (talk) 17:35, 12 August 2011 (UTC)

Covering the Earth with cubes.

TomZ has a great point in this post: http://twistypuzzles.com/forum/viewtopic.php?p=186906

He says that:

R(n) = 6371000+0.057n (radius of n-th layer, zero being the earth's surface) A(n) = pi*(6371000+0.057n)^2 (surface area of n-th layer) C(n) = pi*(6371000+0.057n)^2/0.057^2 (cubes on n-th layer, calculated by dividing surface area of sphere by that of a cube)

Then we simply need to sum the cubes on every layer... 1102 layers would be required.

Apparently whoever wrote the original wiki article probably mistook the Earth's diameter for its radius.

Please correct it.

Thanks. —Preceding unsigned comment added by 206.248.157.60 (talk) 00:13, 15 November 2009 (UTC)

I have removed this sentence: "Alternatively, if laid out on the ground, this is enough to cover the earth with 273 layers of cubes, recognizing the fact that the radius of the earth sphere increases by 57 mm with each layer of cubes." It is uncited, disputed here, and to be honest considering that there are 261 light years of combination, it seems highly unintuitive that there should be only a few hundred layers of cubes if laid out on the Earth's surface! I don't think any such claim should be made until we have a reliable source. The forum linked to above is interesting but I don't think it is a reliable source. This whole section is uncited, so I am going to add a citations needed tag to the section too. Unnachamois (talk) 16:36, 31 January 2010 (UTC)

IMHO as it's stated now it's correct. 275 layers of cubes.

Earth radius = 6371km (check wikipedia earth)

Earth's surface = 4*pi*6371^2 = 510 million square km = 510,000,000,000,000 square m.

1 cube = 57 mm x 57 mm = 0.003249 square m

510,000,000,000,000 / 0.003249 = 156,971,375,807,941,000 (= number of cubes that would fit on the surface of the earth)

[Total number of combinations] / [cubes to cover earth] = 43,252,003,274,489,800,000 / 156,971,375,807,941,000 = 275.5 (Excel tells me)

The only thing I don't know is if the calculation to find the number of combinations is correct and if 1 cube is indeed 57mm*57mm.

No reference needed IMHO, just a good calculator. —Preceding unsigned comment added by 212.78.165.203 (talk) 14:58, 26 October 2010 (UTC)

What's the calculation for the Professor's Cube? kencf0618 (talk) 01:00, 9 November 2010 (UTC)

I disagree with the above unsigned comment saying that no reference is needed. It doesn't matter how good your maths is, Wikipedia is not the place for original research - it is a place for verifiable information! Now, I will concede that trivial calculations such as counting the number of countries in Europe doesn't really need a reference, but this calculation is not trivial. I am midway through a maths degree, so I would feel entirely confident doing this calculation myself and showing my working, but Wikipedia is not the place for that. Thus, this statement should be removed until someone can give a reputable source. Unnachamois (talk) 09:22, 15 August 2011 (UTC)

If we changed the phrasing from "could cover the Earth's surface with a layer 275 cubes thick" to "could cover the Earth's surface 275 times" it would simplify the math considerably without changing the impact of the statement significantly. - Richfife (talk) 18:54, 17 August 2011 (UTC)

Good idea, Richfife. The surface area of the Earth is 510,072,000km^2 according to https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html which is 5.10072e18 cm^2. The size length of a Rubik's cube is 5.7cm according to http://www.dimensionsguide.com/rubiks-cube-dimensions/ so each cube takes up 32.49cm^2, so the number of times we could cover the Earth in Rubik's cubes is 5.10072e18 / 32.49 = 1.5699354e17; dividing the number of combinations by this gives us 4.3252003274489856e19 / 1.5699354e17 = 275.501803, so 275. Unnachamois (talk) 23:03, 27 August 2011 (UTC)

Edit request from 80.229.83.152, 31 August 2011

Patent and Trademark Disputes Nichols assigned his patent to his employer Moleculon Research Corp., which sued Ideal in 1982. In 1984, Ideal lost the patent infringement suit and appealed. In 1986, the appeals court affirmed the judgment that Rubik's 2×2×2 Pocket Cube infringed Nichols's patent, but overturned the judgment on Rubik's 3×3×3 Cube.[13] Even while Rubik's patent application was being processed, Terutoshi Ishigi, a self-taught engineer and ironworks owner near Tokyo, filed for a Japanese patent for a nearly identical mechanism, which was granted in 1976 (Japanese patent publication JP55-008192). Until 1999, when an amended Japanese patent law was enforced, Japan's patent office granted Japanese patents for non-disclosed technology within Japan without requiring worldwide novelty.[14][15] Hence, Ishigi's patent is generally accepted as an independent reinvention at that time.[16][17][18] Rubik applied for another Hungarian patent on October 28, 1980, and applied for other patents. In the United States, Rubik was granted U.S. Patent 4,378,116 on March 29, 1983, for the Cube. Greek inventor Panagiotis Verdes patented[19] a method of creating cubes beyond the 5×5×5, up to 11×11×11, in 2003 although he claims he originally thought of the idea around 1985.[20] As of June 19, 2008, the 5×5×5, 6×6×6, and 7×7×7 models are in production in his "V-Cube" line. Since 1986 the global trademarks and copyright in the Rubik’s Cube have been owned by a UK toy company, Seven Towns Ltd. (hyperlink to website) Seven Towns works with Erno Rubik and Customs agencies to police counterfeit Cubes and appoints official distributers in each country for the growing Rubik range of puzzles and games. Seven Towns Ltd also licenses the rights to the image of the Cube in advertisements, films and TV. 80.229.83.152 (talk) 13:23, 31 August 2011 (UTC)

As far as I can tell the only new material is the final passage:-

Since 1986 the global trademarks and copyright in the Rubik’s Cube have been owned by a UK toy company, Seven Towns Ltd. (hyperlink to website) Seven Towns works with Erno Rubik and Customs agencies to police counterfeit Cubes and appoints official distributers in each country for the growing Rubik range of puzzles and games. Seven Towns Ltd also licenses the rights to the image of the Cube in advertisements, films and TV.

First of all this is unsourced so not an acceptable addition although mention of Seven Towns might be able to go in with a suitable source. However, I don't think it is particularly notable that IPR owners are keen to police their rights; this is normal in any company. Also, under this request system, you are required to provide text exactly as it is to go into the article including reference and hyperlink markup (although we do not usually put links to external sites in the body of the article) so that any confirmed editor can insert it in a straightforward manner. SpinningSpark 17:04, 31 August 2011 (UTC)

Edit request from Rubiksplace, 10 June 2011

please add my new solving guide to the external links. it's a really good one.

www.rubiksplace.com

Rubiksplace (talk) 13:01, 10 June 2011 (UTC)

It doesn't have ads (a big external link no-no). I actually kind of like it. The current link is this one, but I prefer yours. I'm going to swap it out. Don't make me regret it... - Richfife (talk) 17:33, 10 June 2011 (UTC)

That site is down as of Sept. 15th 2011. 217.93.172.207 (talk) 00:27, 16 September 2011 (UTC)

Edit request from 83.167.169.242, 29 September 2011

Patent and Trademark Nichols assigned his patent to his employer Moleculon Research Corp., which sued Ideal in 1982. In 1984, Ideal lost the patent infringement suit and appealed. In 1986, the appeals court affirmed the judgment that Rubik's 2×2×2 Pocket Cube infringed Nichols's patent, but overturned the judgment on Rubik's 3×3×3 Cube.[13] Even while Rubik's patent application was being processed, Terutoshi Ishigi, a self-taught engineer and ironworks owner near Tokyo, filed for a Japanese patent for a nearly identical mechanism, which was granted in 1976 (Japanese patent publication JP55-008192). Until 1999, when an amended Japanese patent law was enforced, Japan's patent office granted Japanese patents for non-disclosed technology within Japan without requiring worldwide novelty.[14][15] Hence, Ishigi's patent is generally accepted as an independent reinvention at that time.[16][17][18] Rubik applied for another Hungarian patent on October 28, 1980, and applied for other patents. In the United States, Rubik was granted U.S. Patent 4,378,116 on March 29, 1983, for the Cube. Greek inventor Panagiotis Verdes patented[19] a method of creating cubes beyond the 5×5×5, up to 11×11×11, in 2003 although he claims he originally thought of the idea around 1985.[20] As of June 19, 2008, the 5×5×5, 6×6×6, and 7×7×7 models are in production in his "V-Cube" line. Since 1986 the global trademarks and copyright in the Rubik’s Cube have been owned by a UK toy company, Seven Towns Ltd. www.seventown.com Seven Towns works with Erno Rubik and Customs agencies to police counterfeit Cubes and appoints official distributers in each country for the growing Rubik range of puzzles and games. Seven Towns Ltd also licenses the rights to the image of the Cube in advertisements, films and TV. — Preceding unsigned comment added by 83.167.169.242 (talk) 12:10, 29 September 2011 (UTC)

Edit request from 83.167.169.242, 29 September 2011

This is request to change the final paragraph from Seven Towns, you are correct that it is the final paragraoh that is the change. It updates the info only. Thanks — Preceding unsigned comment added by 83.167.169.242 (talk) 12:13, 29 September 2011 (UTC)

The first part of SpinningSpark's comments just above still apply. Wikipedia isn't the appropriate place for a company to assert that it is going to enforce its trademarks. - Richfife (talk) 14:37, 29 September 2011 (UTC)

It seems worthy of mention that SevenTown own the tradmark.

http://www.rubiks.com/company/legal.php states that "Rubik® and Rubik's Cube® are registered trademarks throughout the world of Seven Towns Limited. Seven Towns Limited is the exclusive worldwide licensee of copyright in the Rubik's Cube puzzle and is the registered proprietor of European Community Trade Mark registrations in the images of the Rubik's Cube puzzle and the puzzle itself."

So the following would do

Since 1986 the global trademarks and copyright in the Rubik’s Cube have been owned by a UK toy company, Seven Towns Ltd.

We don't need the fact its going to enforce it trademark.--Salix (talk): 14:58, 29 September 2011 (UTC)

Robots assembling the Rubik's Cube

...could be a worthwhile addition to the article. See this.

That page has a hilarious discussion thread. They did it with a standard Lego kit for goodness sake. Seems to be some reliable sources covering this, Daily Mail article for instance. There seems to be some history of Rubik cube-solving machines built from this kit; in a Scientific American article from 2009 two children succeeded in building one. They seem to have been inspired after hearing of robots built by Danny Benedettelli who has been building cube-solving robots since 2007. The earliest cube-solving robot built from the Lego kit that I could trace was built by Irish student Kevin Kelly who wrote his own software. Kelly certainly seems to think he was first himself. Kelly's robot solved in under 10 minutes, compared to Cubestormer II's 5.35 seconds. Sorry, my online link to this last article is behind paywall, but the cite is - Siobhan Hollman, "Rubik robot; Irish student's invention can solve fiendish cube puzzle", Daily Mirror, p.7, 21 May 2004. Kelly must have started in 2003 since it took him nearly a year to build. One of the interesting aspects to me is that all these builders are using different software, it's not as if it was supplied by Lego as part of the kit. SpinningSpark 08:09, 20 October 2011 (UTC)

Another Origin

When I was a schoolboy attending King Edward the 6th Grammar school in Morpeth Northumberland, I saw a boy playing with a toy. This was possibly in 1948. Boys were bringing to school mementos that their Fathers had brought back from their wartime careers. This toy was made from wood and the edges of it were twisted, much like the 'Rubik' cube is twisted. I am certain that this toy was a much earlier sample than that, that was seen by Rubik. So where did it originate? Certainly, in my opinion, Rubik did NOT invent the cube. Someone did it probably before the 1939-1945 war. Bob Ward Loughborough U.K. — Preceding unsigned comment added by 86.140.120.217 (talk) 14:53, 2 December 2011 (UTC)

You may have seen a puzzle box or a burr puzzle.--RDBury (talk) 15:15, 2 December 2011 (UTC)

Update Rubik's Cube

Hi I am Dave from Seven Towns, in the Rubiks cube "patent dispute" section there is no mention that Seven Towns owns the Trademarks to the Rubik's Cube. Can somebody correct this as it is quie important for people looking up how to get rights to use the image ? Thanks Dave

David Hedley Jones. S.V.P. Rubik’s Brand. Seven Towns Limited. 7 Lambton Place, London. W11 2SH Telephone: +44 (0) 207 727 5666.

www.rubiks.com Join us on facebook : rubiksonline. — Preceding unsigned comment added by 80.229.83.152 (talk) 11:57, 19 December 2011 (UTC)

Simpler solution

"The Cube can be taken apart without much difficulty, typically by rotating the top layer by 45° and then prying one of its edge cubes away from the other two layers. Consequently it is a simple process to "solve" a Cube by taking it apart and reassembling it in a solved state."

It's simpler to peel all the stickers off and put them back on in the right place. — Preceding unsigned comment added by 86.156.143.244 (talk) 19:55, 21 December 2011 (UTC)

  Yeah, but the cube usually looks crappy after you finish. 108.27.255.135 (talk) 00:01, 18 January 2012 (UTC)

Rubik's Games

I had a PC game at my house entitled "Rubik's Games," there is an article on wikipedia about it, but no info on the game on the page, not even a link to the PC game page, please add one, i do not have time to do it myself216.115.124.107 (talk) 00:02, 28 February 2012 (UTC)Northern Pyro

A strategy for beginners ...>

> ... who are unlikely to become champion speedcubers, but who are nevertheless capable of learning enough to enjoy the cube.

Spinningspark - I am left wondering what is the true reason why you removed my piece today. You are admittedly correct that it was "not describing an optimal solution ..." but, instead of deleting it, might it perhaps be appropriate to include it under a different heading? You added that I was not [describing] "progress towards [a solution]" - but I have successfully used the strategy which it describes - to teach people how to unscramble the cube. Here, it should perhaps be emphasized that my approach is aimed at people who are not championship material; in other words, it is designed to help those who find the puzzle something of a struggle. Some of my pupils have not managed to advance beyond [what I call] "Level Two" or even "Level One" - but they have still derived enjoyment from it. ("Levels of Difficulty", incidentally, are explained fully in http://dlmcn.com/rubik2.html )--DLMcN (talk) 21:03, 2 March 2012 (UTC)

I meant it was not describing progress towards an optimal solution. Yes, I could have moved it or retitled it, but I am not convinced that it is notable enough for this article. You can find our definition of notability at WP:N. Notability to us is not a matter of opinion, it means something very specific - the subject must have been discussed in a non-trivial way in multiple reliable sources. Again, reliability might not mean what you think it means - read the guideline. Another thing that Wikipedia is considered not to be for is a "how to" guide (WP:HOWTO). That is, we should not be trying to teach our readers how to solve the cube. SpinningSpark 23:56, 2 March 2012 (UTC)

Thank you for replying ... I looked at WP:N and saw: "These notability guidelines only outline how suitable a topic is for its own article or list. They do not directly limit the content of an article or list". However, I am not proposing that my contribution should have its own separate article, so your objection is not covered by that particular Wikipedia clause. I also looked at the guide (WP:HOWTO) which you cited, but it is not at all obvious where exactly you were trying to point me.

In any event (i.e., looking at your second reason for rejection) my aim was not to teach readers how to solve the cube. I would rather describe it as highlighting an aspect of cube-theory which is not touched upon elsewhere in the article. So - yes - it would be better with its own sub-heading.

I have been active in Wikipedia for some years now - on a number of different topics - and it is clear that "reliability" is not always easy to pin down and define rigorously. You state that "you are not convinced" that my contribution merits inclusion, and you are entitled to your own personal opinion. Thus, in that context, I could perhaps mention that I have shown my write-up to several cubists - including Jessica Friedrich, and she liked it and praised it. [I do recognise, of course, that an e-mail to me from Jessica cannot be regarded as a "reliable source" - but it does at least offer a balance to the fact that you do not like my article]. --DLMcN (talk) 07:15, 3 March 2012 (UTC)

I have not said I did not like your article - if I was just starting out solving cubes it is just the sort of thing I would want to read. If Jessica Friedrich has praised the method in a reliable source then it is certainly worthy of inclusion, otherwise it is unverifiable and non-notable. You are correct that the notability guidelines are aimed at subjects for articles, but some common sense needs to be applied here: there are a great number of methods for solving the cube and we have a need to apply some standard of inclusion. In any case there is still the requirement to cite reliable sources, and self-published sources do not count as reliable, however good. Now that you have revealed that you are the author of the method, another guideline is relevant, WP:COI: it is obviously difficult for you to write about this neutrally and you should really leave it to other editors. I agree that your contribution did not amount to a "how to" and I apologise for giving that impression. I was responding to your first post here which very much gives the impression you wanted to write a how to guide. SpinningSpark 07:39, 3 March 2012 (UTC)

OK, thanks ... My contribution was a genuine attempt to enrich the content of the Wikipedia article - but we'll leave it at that. --DLMcN (talk) 08:21, 3 March 2012 (UTC)DLMcN (talk) 19:05, 3 March 2012 (UTC)

Relevance and application of mathematical group theory

SpinningSpark and other editors ...

I noticed these comments near the top of this Talk-Page: "Rubik's Cube was one of the Mathematics good articles, but it has been removed from the list. There are suggestions below for improving the article to meet the good article criteria".

Here then is a suggestion for a new section:

Rubik's Cube lends itself to the application of mathematical group theory, which has been helpful for deducing certain algorithms - in particular, those which have a commutator structure, namely XYX'Y' (where X and Y are specific moves or move-sequences). In addition, the fact that there are well-defined subgroups within the Rubik's cube group, enables the puzzle to be learned and mastered by moving up through various self-contained "Levels of Difficulty". For example, one such "Level" involves solving cubes which have been scrambled using only 180-degree turns.

DLMcN (talk) 18:40, 4 March 2012 (UTC)

This has little to do with the article's removal from GA - the problems concerned the referencing and the lede, see here. Those are the things that need to be addressed to get back GA status.

A section on the cube group summarising the Rubik's cube group article under a {{main}} banner is a good idea. Using this as a vehicle to work in an otherwise unacceptable link is not. SpinningSpark 19:33, 4 March 2012 (UTC)

OK, fair enough then ... a reference to Singmaster's notes should cover it adequately. --DLMcN (talk) 22:20, 4 March 2012 (UTC)

New blind record

Please change "New record was born at the Zonhoven Open 2012 in Belgium in blind solving when the Hungarian Marcell Endrey solved a cube in 28,8 seconds." to "A new record was set at the Zune Open 2012 in Belgium for blind solving when the Hungarian Marcell Endrey solved a cube blindfolded in 27.65 seconds."

Done. But next time please also provide a citation. I knew where to find a reference in this case, but editors who answer these templates generally will not. SpinningSpark 16:03, 3 May 2012 (UTC)

Colors and placement

For a period in time, around the release of Rubiks Revenge, white was always opposite blue, but cubes made before and after this period don't follow that pattern. I recently bought an 5x5x5 "Rubik's 5x5 cube" (made in China), that didn't follow the white opposite blue pattern. I have two of the older "professor" 5x5x5 cubes, with white opposite blue, and the orange stickers that didn't stick too well (heating and/or regluing them seemed to help). Rcgldr (talk) 17:44, 5 June 2012 (UTC)

number of permutations

I'm probably completely wrong here, but since there are only six colours on the rubik's cube, isn't the number of combinations actually much lower than 43 quintillion, since many squares of the same colour can be in different locations and still produce the same combination, for example it isn't a different combination if the cube has two combinations that are identical, but have different squares of the same colour in the same place. Sorry if I'm explaining it really badly, but could anyone explain to me how this is taken into account. —Preceding unsigned comment added by Js1056 (talk • contribs) 09:36, 22 May 2010 (UTC)

You are, as you say yourself, completely wrong. The explanation of how this number is arrived at is in the article immdediately above the 43 quintillion figure. The mistake you are making is that you are considering the elements of the puzzle to be the squares (ie the coloured stickers) when you really need to consider the solid pieces, or "cubies" as the solvers call them. For instance an edge cubie might have one red sticker and one blue sticker. The red sticker of this cubie in a solved cube cannot go just anywhere on the red face. In fact there is one, and only one, position it can go. That position is the edge between the red face and the blue face since the blue sticker has to be on the blue face as well as the red sticker on the red face. What is more, the solver has to place it there in the correct orientation - it is no good having it flipped over, with the red sticker on the blue face and the blue sticker on the red face. Hope that helps. SpinningSpark 10:34, 22 May 2010 (UTC)

I have a follow-up question. Does the math calculating the number of permutations take into consideration that some color positions are not possible, i.e. some colors combinations can only be at opposite faces, and not adjacent? — Preceding unsigned comment added by 75.167.0.155 (talk) 04:39, 20 June 2011 (UTC)

Yes, of course. SpinningSpark 16:54, 20 June 2011 (UTC)

What about if I take the same pattern and simply lay the cube on a different face, is this considered a new permutation? I think we should only consider permutations that are unique regardless of cube orientation. — Preceding unsigned comment added by 75.167.0.155 (talk) 21:40, 20 June 2011 (UTC)

three types of pieces, 8 corner pieces destributed on 8 possible positions each with 3 possible orientations ((3^8)*(8!)), 12 middel pieces, 12 positions each with 2 possible orientations ((2^12)*(12!)) and then the 6 center pieces with fixed positions, but each with 4 possible orientations (4^6).. so shouldn't the real number of (im)possible permutations be (3^8)*8!*(2^12)*12!*(4^6)=2,125,922,464,947,725,402,112,000 and not 3^8)*8!*(2^12)*12!=519,024,039,293,878,272,000  ?? — Preceding unsigned comment added by 62.44.135.149 (talk) 13:51, 17 July 2012 (UTC)

On a supercube, or on a cube with contiguous images across the stickers, yes, center orientations would matter. But for the standard cube they do not, so they are ignored. Specs112 t c 14:00, 17 July 2012 (UTC)

Server problem?

When I make an edit, something weird happens to the references.

It isn't happening for me. Try using a sandbox until you can figure out the problem. - Richfife (talk) 22:30, 20 July 2012 (UTC)

Incorrect World Records

The records for fewest moves and multibld are incorrect. I would fix them however, I cannot because the page is protected. The sources are the same but the people and number of moves/cubes are different. Vcuber13 (talk) 16:52, 5 August 2012 (UTC)

I have confirmed your account so you should now be able to edit. Let me know if you have any problems. SpinningSpark 19:46, 5 August 2012 (UTC)

Notability of phrase "twisty puzzles"

Hi. Spinningspark, I see now that the phrase mechanical puzzles means something different, so thanks for changing that back. But with the quotes around "twisty puzzles", it implies the phrase is special or in common use or popular slang or something. The phrase is not linked to its own article (maybe this is the real solution) or a reliable source to show that it is in common use. This is my $0.25, as someone who grew up playing with and collecting many of these puzzles but hasn't heard the description "twisty puzzles". It makes perfectsense, but that's not what's important; it does need to be verifiable to ensure it's not biased regionally or commercially. Cheers. --Ds13 (talk) 00:39, 4 November 2012 (UTC)

I'm not particularly trying to defend the phrase twisty puzzles, rather I'm disputing that mechanical puzzle is an improvement since the latter is a much more general phrase encompassing all sorts of other things. But I would point to a very large number of ghits for the phrase. Here is a book use and a use in a patent and another book use. SpinningSpark 02:06, 4 November 2012 (UTC)

Agreed. I just noticed that twisty puzzle redirects to combination puzzle (since 2009), and that article does a nice job placing Rubik's Cube within its scope. So as a subset of mechanical puzzles, I think "combination puzzle" gives the reader a more useful category to work with in the intro. Updated, accordingly. Regards. --Ds13 (talk) 06:29, 4 November 2012 (UTC)

I don't agree with combination puzzle either. It is better than mechanical puzzle but still not as accurate as twisty puzzle. Combination puzzle includes, for instance, the 15-puzzle and Rubik's Magic, neither of which is a twisty puzzle, but they are a subset of combination puzzles, hence the redirect. You dispute the notability of twisty puzzle (by the way, there is no requirement for notability of word usage - it is notability of article subjects that is policy on Wikipedia) but are quite happy to substitute combination puzzle which has no provenance outside Wikipedia, at least in this sense, except where it has been copied from us. When I wrote the combination puzzle article I would probably have called it twisty puzzle if I had been aware of that phrase at the time and excluded the other stuff (an early try, not my best effort on Wikipedia). Or else I would have called it the more citable sequential move puzzle if I wanted to include the other stuff (I would support it being moved to that name now]]. As I said in my original edit summary reverting you, it would be possible to use a technically accurate descriptive phrase such as three-dimensional sequential move cyclic plenary puzzle but this is not anywhere near as useful to our readers as the simple twisty puzzle.

Okay, it looks to me like everything 3D in the combination puzzle article is a "twisty puzzle". So we could split that article. The remaining combination puzzles can live on in that article, while the twisties can now be called what they are, without redirect. --Ds13 (talk) 15:51, 4 November 2012 (UTC)

I'm fine with you separating out twisty puzzle into its own article, but it is not necessary to do that in order to use the term in this article. A bit more care than your simple division needs to be exercised:- the items under "Non-Rubik style three-dimensional" (which could now be renamed "Non-twisty") are 3D but do not belong in Twisty puzzle. Also, what would you propose to do about software-only puzzles (many of which are not possible to implement mechanically) if twisty puzzle is to be defined as a subset of mechanical puzzle? Also combination puzzle should still retain a summary of the contents twisty puzzle with a {{main}} section hatnote. As I noted above, any reorganization should also rename combination puzzle to sequential move puzzle. SpinningSpark 18:56, 4 November 2012 (UTC)

Help phasing this

I recently edited this part of the page:

Similar puzzles have now been produced with various numbers of sides, dimensions, and stickers, not all of them by Rubik.

I don't like the 'various numbers' part and don't think it sounds dramatically correct. Any suggestions on how to change this to make it sound more logical.

Thanks, - Thomas — Preceding unsigned comment added by Cheese512 (talk • contribs) 06:28, 30 December 2012 (UTC)

Lead picture

Why are we using someone's illustration of a Rubik's cube, when many photos of the product exist? No matter how pretty the illustration is, it's still someone's unofficial interpretation. If no one objects I'm going to substitute an actual photograph of an actual Rubik's cube. —Designate (talk) 16:43, 3 February 2013 (UTC)

This isn't something I feel all that strongly about, but I like the cleanliness of the svg image. This article covers both the cultural impact of the product and the mathematical properties of the cube, so a somewhat more abstract image seems appropriate. I'm not going to squawk either way, though. - Richfife (talk) 18:53, 3 February 2013 (UTC)

Did Rubik take 3 months to solve?

This sentence,

"it was solved first by the man himself mr rubiks,it took him 3 months to solve it"

has just been deleted from the article. Just wanted to point out that something like it is citable. This book says " it took Rubik a month" and this New Scientist book review makes it clear that the issue for Rubik was to find solutions that were not simply reversing the moves taken to scramble the cube. SpinningSpark 13:12, 4 February 2013 (UTC)

How much context is there? If he was busy in real life, it doesn't mean much. If he was working on it 8 hours a day, it does. - Richfife (talk) 18:06, 4 February 2013 (UTC)

I don't really know the answer to that, but it is clear that Rubik put some effort into it and considered it an important issue. There is a longer quote here. I did have the title of the original Hungarian document at one time but google is refusing to spit it up at the moment. Here is a longer description that is clearly taken from the same source,

Erno Rubik was a designer who built the cube because he liked playing with geometric figures. His room was filled with cardboard and wooden figures. He was intrigued by the challenge of how to move blocks in a cube independently without the cube falling apart. Using an engineering technique, Rubik built the blocks so that they held themselves together. During testing, he colored each side of a block a different color. As he turned the blocks randomly, he was fascinated by the parade of colors.

A month later he emerged with the answer. Rubik speculated that the challenge would hook others as well. When Rubik decided to put the blocks back in their original configuration, he faced a bigger challenge. How to get home? As he twisted more, the colors became more scrambled. Rubik decided there must be a method to restore the originall order, and he closeted himself in his bedroom to find the solution. A month later he emerged with the answer. Rubik speculated that the challenge would hook others as well. He was right.[4]

I don't really care much whether this is in the article or not. I was just providing some solid refs for the discussion. Although I think most people would find it an interesting factoid. SpinningSpark 19:19, 4 February 2013 (UTC)

Is there an algorithm for Gödel numbering?

The number of all possible positions is known and finite. Is there an (efficient) algorithm that assigns each possible position its Gödel number and vice versa? --RokerHRO (talk) 19:36, 18 February 2013 (UTC)

God's number

The article says:

This is optimal, since there exist some starting positions which require at least 20 moves to solve. More generally, it has been shown that an n × n × n Rubik's Cube can be solved optimally in Θ(n² / log(n)) moves.

But 3*3/log(3) is between 18 and 19. So one of the two sentences is wrong.--Sergei (talk) 21:07, 29 October 2011 (UTC)

You're not reading the Θ notation correctly. It doesn't give specific bounds on the number of moves, it only tells you the shape of the function as n grows. Follow the link to the article on Big O notation for details.--RDBury (talk) 21:54, 29 October 2011 (UTC)

soooo, what do we got here, some simple to complex search strategy, possible a mini computer n memory markers to help 4 mem time compromise plus a factorial (6) factor time optimizing ... i bet u cant do more :P u basically need others ideas like progressive depth search cz branch n bound requires the target solution also 93.118.212.93 (talk) 15:33, 10 March 2013 (UTC)

hmm, O(n*n/log(n)) optimally... well thats a good challenge 4 reverse eng reeng, thank You 93.118.212.93 (talk) 18:37, 11 March 2013 (UTC)

well, lemme c: considering 10*10*10 cube n b NN the number of different combinations of the cube a hypotetical machine that starts with solution n trying to uniformly depth scan 4 generating all combinations of the cube got 10*3*3 =90 posibilities of choice at a step... a lower value 4 God,s Number will it be Log_base_90(NN) this looks like main idea to follow from me so far ;)) 93.118.212.93 (talk) 19:00, 11 March 2013 (UTC)

Attention

The "Rubik's cube solution walkthrough reference seems to be infected! — Preceding unsigned comment added by 77.196.153.92 (talk) 03:32, 15 April 2013 (UTC)

Yeah, it downloads something and tries to run it. I've removed the link. SpinningSpark 08:12, 15 April 2013 (UTC)

Edit request on 27 June 2013

Hello, I think that the following websites should be added to the Rubik's cube page as they are the official Hungarian Rubik's websites by Rubik Studio. www.rubikkocka.hu for speedcubers and www.rubik.hu for everyone else. Thanks. Pelikan2379 (talk) 16:41, 27 June 2013 (UTC)

Which of the current sites do you suggest should be removed to make room? Thanks! - Richfife (talk) 16:57, 27 June 2013 (UTC)

Not done: If the links are relevant I would have no problem adding them to the article without removing anything else. However, there is already a link to the official Rubik's Cube website in English (which seems to overlap the content of your second link), and your other link is a Hungarian Wordpress site. If as you say it's a site for speedcubers, I have little doubt that there are similiar sites in many world languages. You'll need to give a bit more information about how these Hungarian-language sites are important enough to be included in the English-language Wikipedia for them to be added here. --ElHef (Meep?) 16:40, 30 June 2013 (UTC)

Semi-protected edit request (II) on 15 June 2014

Hello spinningspark. I am truly sorry for posting promotional items on the page. Maybe I am not a good editor However, like in the earlier message, the vcube company too was being promoted. So let's make a deal My edits can be removed, as long as bias towards v-cubes is removed, this is spreading a wrong message. Also, the legal 13x13x13 should be displayed. I have the non-promotional links (at least some are) 1.- 2.- (that the video) 3.-

I would also like to point out that there is controversy about the legality of the vcube 4. It is said that vcubes have violated another's patents. No need to add that. Images are in the links.

Once again, I do apologize for the mistakes i made- i'm new. Thanks a lot. TheMoyuGuy (talk) 12:01, 15 June 2014 (UTC)

Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. Hello TheMoyuGuy. In order "ping" Spinningspark (which I have just done), or any other user, you need to wrap their name in a template like the {{U}} template so it would look like {{U|Spinningspark}}. SS, I see that you have confirmed TheMoyuGuy's account, and then immediately removed it again. I've never seen it done that way before, I was confirmed by an administrator when I first started editing, and it wasn't removed until after I was already in the autoconfirmed category as well. That aside, it's not entirely clear to me what you want changed here TheMoyuGuy, could you please give a please change "X" to "Y" description of what you want changed? Thanks for your interest in contributing to the English Wikipedia! — {{U|Technical 13}} ^{(e • t • c)} 15:12, 15 June 2014 (UTC)

@Technical 13: I was a little dubious about some of the things that the user was proposing to add, but the page is not protected in order to keep out people I do not agree with, it is protected to keep out vandals. As the person protecting the page, I feel duty bound to confirm anyone who wants to edit without too much questioning. However, this editor inserted a spammy link which I removed and replaced with citation needed. They then started edit warring to keep the link in. Clearly, this was not a suitable person to have given confirmed status to. Also now clear, from the link, the user's name, and the content, that this was all a subtle attempt to promote Moyu in the article by a COI editor. I consequently then reverted the editor's contribution in its entirety. A neutral editor may be able to salvage something, but this editor should not be touching the article at all. SpinningSpark 15:28, 15 June 2014 (UTC)

• Ahh. Spinningspark, that makes perfect sense. I didn't mean to come off as questioning your judgement, and if I did, I apologize. Either way, thanks for clarifying. Happy editing! — {{U|Technical 13}} ^{(e • t • c)} 15:33, 15 June 2014 (UTC)

You are perfectly entitled to question any admin decision, and I certainly won't take offence at it. None of us is above the community. SpinningSpark 15:44, 15 June 2014 (UTC)

Edit Request from Sailingthrough (talk) 16:11, 30 July 2013 (UTC)

The record for the 3x3x3 cube was broken by Feliks again today, currently stands at 7.36 seconds. Source: http://www.bbc.co.uk/news/world-asia-23503164

User:Sailingthrough, I have confirmed your account so you should now be able to edit the article yourself. SpinningSpark 16:57, 30 July 2013 (UTC)

Edit Request from Slinky773 (talk) 05:39, 18 July 2013 (UTC)

Records should be updated. In the feet solving section, information is incorrect. Record average should be of Yunsu Nam with 35.15 seconds at Cubing Korea Xmas Eve 2011.

Edit request

Rubik's now uses plastic tiles, instead of stickers. please change stickers to plastic tiles. 117.202.152.203 (talk) 16:16, 16 December 2013 (UTC)

I oppose such a change. This should be mentioned separately. The second reference to stickers includes non-Rubik manufacturers and both references are still true of legacy cubes. We also need a WP:RS to confirm this fact. SpinningSpark 19:40, 16 December 2013 (UTC)

The text uses the term "classic Rubik's Cube", which uses stickers. I wouldn't revert a change to make it say "stickers or tiles", but I wouldn't do it myself. - Richfife (talk) 23:17, 16 December 2013 (UTC)

I agree with not wanting to remove the reference to the stickers, and agree with needing a reliable source either way. I'm closing the edit request as unsourced and no consensus. --ElHef (Meep?) 23:58, 16 December 2013 (UTC)

Rubik‘s Cube Patent

In the text is stated that Rubik obtained Hungarian patent HU170062 for his Magic Cube in 1975. However, in 1975, he only filed his patent application. The patent was granted in 1976 (announcement in the Official Gazette of Patents and Trademarks) and published in 1977. See the Website of the Hungarian Patent Office: epub.hpo.hu/e-kutatas/?lang=EN

Therefore, I propose to write that Rubik obtained Hungarian patent HU170062 for his Magic Cube in 1976. — Preceding unsigned comment added by Skorovs (talk • contribs) 22:47, 20 January 2014 (UTC)

Impossible Situations on the Rubik's Cube

Hello, I am new to Wikipedia. I would like to let the general public know that there ARE actually impossible situations on the Rubik's Cube. For instance, rotating only one corner is impossible. Switching one edge is impossible. Switching two corners is impossible. Switching centers is impossible (Although you can move them around in such a way that they do not pair up, but only in a certain way). Quoting from the mathematics section of the Rubik's Cube article on Wikipedia, "Permutations The original (3×3×3) Rubik's Cube has eight corners and twelve edges. There are 8! (40,320) ways to arrange the corner cubes. Seven can be oriented independently, and the orientation of the eighth depends on the preceding seven, giving 37 (2,187) possibilities. There are 12!/2 (239,500,800) ways to arrange the edges, since an even permutation of the corners implies an even permutation of the edges as well. (When arrangements of centres are also permitted, as described below, the rule is that the combined arrangement of corners, edges, and centres must be an even permutation.) Eleven edges can be flipped independently, with the flip of the twelfth depending on the preceding ones, giving 211 (2,048) possibilities.[25] {8! \times 3^7 \times (12!/2) \times 2^{11}} = 43,252,003,274,489,856,000 which is approximately 43 quintillion.[26]," this is actually incorrect. In this section of the article, it says that "Seven can be oriented independently". I cannot currently prove that this is incorrect, but try taking apart your Rubik's Cube and twisting a corner or an edge piece. Then try to solve it. Am I right? Is this impossible?

• Thank you for taking your time to read this -- I have been wanting to post this for a long time. — Preceding unsigned comment added by 173.10.109.65 (talk) 19:24, 31 January 2014 (UTC)

The article already covers this under permutations. If "seven can be orientated independently" implies that just one (the eigth corner) cannot. That means one cannot twist just one corner. SpinningSpark 22:08, 31 January 2014 (UTC)

Notation and solutions

I can't quite put my finger on it, but I think there's some systematic bias going on here. From what I recall (and, indeed, is backed up by sources, though not as many as I would like), the most popular and easily identifiable solution in the UK was Patrick Bossert's. I've never heard of any of the other solutions, but I'd recognise his notation instantly. Though this blog suggests that solutions have improved in the last 30+ years, You Can Do The Cube was a best-seller in the cube's heyday of the early 80s, and per WP:DUE should get the appropriate prominence. What do others think? Ritchie333 ^{(talk) (cont)} 13:07, 30 April 2014 (UTC)

Changed domain name for cubezzz.dyndns.org

Hi folks,

Dyndns.org as dropped all free accounts so I had to change the URL of my forum from http://cubezzz.dyndns.org/drupal to http://cubezzz.duckdns.org/drupal .

There's one URL that the Rubik's Cube wikipedia page references that is affected by this change so if someone could just change the dyndns part to duckdns that should fix things. I don't seem to have the authority to make any changes myself.

Thanks — Preceding unsigned comment added by Cube1024 (talk • contribs) 19:51, 8 May 2014 (UTC)

Done. - Richfife (talk) 20:15, 8 May 2014 (UTC)

20 moves max.

http://www.dailymail.co.uk/sciencetech/article-1302414/Study-uncovers-possible-Rubiks-Cube-solution-Only-20-moves-needed.html So, ideally only a maximum of 20 moves is needed to solve a Rubik's cube from any position? — Preceding unsigned comment added by 178.222.134.207 (talk) 21:54, 10 May 2014 (UTC)

Semi-protected edit request on 19 May 2014

Edit request (19 May 2014)

Notable comment. Edward Snowden flew to Hong Kong on the 39th birthday of the Rubik's Cube, and he used a Rubik's Cube as a signal to confirm his identity to meet the journalists. — Preceding unsigned comment added by 203.226.200.91 (talk) 14:59, 19 May 2014 (UTC)

No, I don't think so (8!) times (12!), not more

The 20 pieces, 12 edges and 8 corners, can be placed at (12!) times (8!) places not more!

The pieces are turned the same way internally as there position in the whole cube, relative to the six center pieces. The same position means also the same orientation. 84.118.81.7 (talk) 19:03, 10 June 2014 (UTC)

Really? Then how do you explain this,

Are you actually able to solve the cube yourself? SpinningSpark 21:44, 10 June 2014 (UTC)

Yes, how do you solve this? --84.118.81.7 (talk) 08:44, 11 June 2014 (UTC)

But, really, turning it to the back on the right side and then back to the original position. Yes it is turned. 84.118.81.7 (talk) 08:55, 11 June 2014 (UTC)

B⁻¹FDF⁻¹D²R⁻¹DU²R⁻¹D⁻¹RD²FD⁻¹F⁻¹U²B SpinningSpark 14:36, 11 June 2014 (UTC)

Semi-protected edit request on 15 June 2014

Hello. I would like to change the article "https://en.wikipedia.org/wiki/Rubik%27s_Cube" for the following reasons:- 1. It is moderately biased, towards V-Cubes. There is also slight prejudice against V-Cubes and moderate prejudice towards other companies. 2. It needs to be updated. 3. It needs citations.

The part(s) I would like to edit is/are as follows:- 1. Many Chinese companies produce copies of, and in some cases improvements upon, the Rubik and V-Cube designs. The most popular are Bao Daqing's DaYan company, who make the GuHong and ZhanChi and now PanShi models, amongst others. They are often preferred over the originals by expert speed cubers because of their ease of movement.

Reason:- It is heavily biased, link is inappropriate. This shows how much news agencies and others know about the speedcubing community. They do not respect the thoughts of those in the cubing community, saying that "Chinese" companies "illegally" produce "knockoffs" "using patents". You must prove that it is a knockoff. Also, Daqing Bao's DaYan was allowed by V-Cube themselves as the cubing community was upset that they banned it even though the mechanism was different, hence they allowed it. Also, a cube cannot be considered a knockoff if it does not contain the mechanism of a patented cube. That way V-cubes too are knockoffs. Right?

2. Non-licensed physical cubes as large as 11×11×11 based on the V-Cube are commercially available to the mass-market circa 2011 in China; these represent about the limit of practicality for the purpose of "speed-solving" competitively (as the cubes become increasingly ungainly and solve-times increase exponentially). These cubes are illegal (even in China) due to the fact that they violate Panagiotis Verdes' patents; however some countries do not enforce patent law strictly, leading to their general availability. In addition, Chinese companies have produced 3×3×3 cubes with variations on the original mechanism that, while legally controversial, are generally considered to be superior for competitive speedcubing.

Reasons:- 1. We DO need citations. 2. 13x13x13 cubes have been legally, with no doubt produced and are going to be mass produced VERY soon. 3. HEAVY BIAS.

I would also like to edit other parts due to moderate/slight bias

And, if the request is approved, I WILL give reliable sources as links. TheMoyuGuy (talk) 06:22, 15 June 2014 (UTC)

I have confirmed your account so that you are now able to edit the article. Regarding your claim "a cube cannot be considered a knockoff if it does not contain the mechanism of a patented cube". Us ordinary folk might think that, but the courts live in a different universe where the ordinary laws of gravity do no not apply. Moleculon won their case against Ideal for the 2x2x2 cube even though Nichols' mechanism was utterly different from Rubik's (Nichols' cube was simply held together by magnets, an arrangement, as far as I know, that has never actually been produced). Nichol's claimed the idea of such a cube in his patent, regardless of mechanism. Ideal kept the rights to the 3x3x3 cube because Nichols had failed to mention that higher order cubes were possible in his patent. Common sense is likely to lead you astray on legal issues, stick rigidly to the sourcees. SpinningSpark 08:13, 15 June 2014 (UTC)

Tony Fisher

Could some one please change the reference to Tony Fisher in the text to include a link to the Tony Fisher (puzzle designer) wikipedia page?

Thanks Razumukhin (talk) 14:03, 19 July 2014 (UTC)

I've confirmed your account, do it yourself. SpinningSpark 17:30, 19 July 2014 (UTC)

Thanks Razumukhin (talk) 15:48, 20 July 2014 (UTC)

Rubik's cube by loop sequence

If you start from the solved cube and turn four sides in sequence (around the cube - for example sides: front, left, back, right - again and again) in the same manner (counter-clockwise for example) - how many times would you have to turn sides in order to get to where you started from (full circle back to the solved state)? Also: Could the cube be brought to the solved state from any given state by using that sequence or it has to be one of the states achieved through that sequence?— Preceding unsigned comment added by 178.223.86.207 (talk • contribs) 21:48, 2 January 2014

I did this once many years ago and it does eventually loop back, but it takes a very long time (I was bored). I would suggest trying it and counting. Not sure that needs to go in the article, though. No, it won't cycle through all positions, so it's not a solution. It would take millions of years on average if it was. - Richfife (talk) 22:27, 2 January 2014 (UTC)

hello Thanks for a quick answer, great info. I found this now: http://dogschool.tripod.com/cubegroups.html . It says that exactly 1260 turns is required for that particular loop-sequence. Maybe there are some other interesting facts for the article to be found on that site. — Preceding unsigned comment added by 178.223.86.207 (talk) 01:46, 3 January 2014 (UTC)

Since the corners are affected by the move F like

F = {1, 2, 3, 4} {5} {6} {7} {9}

the sequence FRBL does

FRBL = {1, 7} {2, 4} {3, 6} {5, 8}

that is, four 2-cycles so (FRBL)² will return the corners to their original combination (ignoring twists - for now). For the edges,

FRBL = {1, 2, 3, 5, 6, 8, 9, 11, 12} {4, 10, 7}

a 9-cycle and a 3-cycle. The lowest common multiple (LCM) of a 9-cycle and a 3-cycle is a 9-cycle, hence the edges will be returned to their original combination by (FRBL)⁹ (ignnoring flips).

The LCM of a 2-cycle and a 9-cycle is a 18-cycle hence

M = (FRBL)¹⁸ (72 moves)

is required to return both corners and edges to their original combination. However, if they do not return with the correct twists and flips (haven't checked, can't be bothered, too much effort, but I seem to remember - from my now highly unreliable memory - that when I actually tried this move over 30 years ago it did twist and flip) then the sequence will have to be repeated to correct this. Twists are 3-cycles and flips are 2-cycles. The LCM of both is a 6-cycle, hence

M⁶ = (FRBL)¹⁰⁸ (432 moves) = {∅}

A tediously long sequence but obviously much less than a complete solution since only 432 different positions are achieved. By the way, any sequence at all is guaranteed to eventually return to the original combination because there are only a finite number of combinations possible with a finite piece-state puzzle. SpinningSpark 10:01, 3 January 2014 (UTC)

Has anyone looked at the problem of what the smallest algorithm that will traverse the entire position set of the cube when repeated is? There's probably not an easy answer for that. - Richfife (talk) 21:47, 3 January 2014 (UTC)

They have. It's called The Devil's Number - Richfife (talk) 21:49, 3 January 2014 (UTC)

Is that algorithm meant to work in a fashion that the end result of a full such single sequence after it's completed is one cube combination which adds to the list to form a completely ordered full list of all possible combinations (when repeated sufficient number of times; repeating a great deal of combinations "in transit") or is it meant to make some kind of "messy" jumps from one place in that list to another? (the point being that maybe there can be a really simple sequence which can run through ALL of the cube combinations (ideally without combination repetitions...) if the sequence is crunched down to that other kind of sequence - with "disordered results" which jumps all over the list of combinations and may even give a solved state wherever in the midst of sequence - cause even every quarter-turn gives a different combination from that full list) — Preceding unsigned comment added by 93.87.252.113 (talk) 18:56, 14 January 2014 (UTC)

The guy has not actually found a Devil's number for the Rubik Cube. The best he has done is find it for a subgroup (limited to X², ie double turn, moves) of the Pocket Cube. According to the Rubik's Cube group article, this is actually impossible. The largest cyclic group that can be generated by any Rubik's cube move is 1260 (cited to David Joyner's book). Obviously much too small to generate the entire Rubik group. SpinningSpark 14:28, 30 December 2014 (UTC)

Semi-protected edit request on 10 May 2014

Please change "Philip Marshall's The Ultimate Solution to Rubik's Cube is a modified version of Fridrich's method, averaging only 65 twists yet requiring the memorization of only two algorithms.[45]"

to "Philip Marshall's The Ultimate Solution to Rubik's Cube is a modified version of Fridrich's method, averaging only 65 twists yet requiring the memorization of only two algorithms.[45] Subsequently, Camilo V. L. Amaral simplified the method to use only one algorithm, calling it "The Less is More Method" [5]"

This method is important and original because: (1) for the use of just one algorithm that is learned intuitively, (2) it's extremely easy and therefore a solution suitable for beginners and yet(3) you don't need to memorize any sequence, just understand the process and what you are doing, so it is the only easy introduction for conscientious cube solution --2a01:388:23b:158::1:7 (talk) 21:09, 11 May 2014 (UTC)

Request declined. No indication that the new method and name has gained any traction in general. Youtube video provided as reference only has 120 views. - Richfife (talk) 23:13, 11 May 2014 (UTC)

Objection Please reconsider, as the video has over 6000 views. In addition, there is no mention about single algorithms in the 'Optimal Solutions' section of the wikipedia. Since this request two new methods have been developed, as you can see in the section "Single algorithm methods" in the wikibook link http://en.wikibooks.org/wiki/How_to_Solve_the_Rubik%27s_Cube— Preceding unsigned comment added by 5.151.2.26 (talk • contribs)

Request declined. Youtube videos are generally not accepted as reliable sources. Exceptions can be made for recognised experts "whose work in the relevant field has previously been published by reliable third-party publications" (WP:SPS) but this person would not seem to meet that requirement. In any case, 6000 views is nothing for Youtube. There are Rubik's cube videos out there with views in the millions. Besides which, much of the video is taken up with him fumbling around making errors - I found it too painful to watch more than the first ten minutes. SpinningSpark 21:41, 26 January 2015 (UTC)

Semi-protected edit request on 6 April 2015

I believe that there are numerous small (yet important) details not included.

whitefieldcat (talk) 22:50, 6 April 2015 (UTC)

Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. Kharkiv07^Talk 22:55, 6 April 2015 (UTC)

Semi-protected edit request on 30 April 2015

2601:9:8681:320:B4D3:CCD4:4B9A:3B4D (talk) 04:15, 30 April 2015 (UTC)

Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. Stickee (talk) 04:24, 30 April 2015 (UTC)