英语课课前演讲魔方.pptx

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1、Rubiks Cube is a toy puzzle designed by the Hungarian architect Ern Rubik(1944-)in 1974,which was very popular in the 1970s and 1980s.Originally called the Magic Cube,the puzzle was licensed by Rubik to be sold by Ideal Toy Corp.As of January 2009,350 million cubes had been sold worldwide making it

2、the worlds top-selling puzzle game.It is widely considered to be the worlds best-selling toy.Introduction第1页/共26页Rubiks Cube is a was invented by the Hungarian architect Ern Rubik.Inventor第2页/共26页In the mid-1970s,Ern Rubik worked at the Department of Interior Design at the Academy of Applied Arts an

3、d Crafts in Budapest.Although it is widely reported that the Cube was built as a teaching tool to help his students understand 3D objects,his actual purpose was solving the structural problem of moving the parts independently without the entire mechanism falling apart.In general,it is a magic cube w

4、hich shows the beauty of architecture.Inventions第3页/共26页StructureThe original Rubiks Cube is made up of 26 smaller cubes,each face of which is a different color.There are six central pieces which show one colored face,twelve edge pieces which show two colored faces,and eight corner pieces which show

5、 three colored faces.Each piece shows a unique color combination,but not all combinations are present.第4页/共26页MathematicsThere 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)possibili

6、ties.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.第5页/共26页(When arrangements of centers are also permitted,as described below,the rule is that the combined arrangement of corners,edges,and centers must

7、 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.Mathematics第6页/共26页SolutionsAlthough there are a significant number of possible permutations for the Rubiks Cube,a number of solutions have b

8、een developed which allow solving the cube in well under 100 moves.第7页/共26页Many general solutions for the Rubiks Cube have been discovered independently.David Singmaster first published his solution in the book Notes on Rubiks Magic Cube in 1981.30 This solution involves solving the Cube layer by la

9、yer,in which one layer(designated the top)is solved first,followed by the middle layer,and then the final and bottom layer.After sufficient practice,solving the Cube layer by layer can be done in under one minute.Solutions第8页/共26页A solution commonly used by speed cubers was developed by Jessica Frid

10、rich.It is similar to the layer-by-layer method but employs the use of a large number of algorithms,especially for orienting and permuting the last layer.Solutions第9页/共26页The cross is done first,followed by first layer corners and second layer edges simultaneously,with each corner paired up with a s

11、econd-layer edge piece,thus completing the first two layers(F2L).This is then followed by orienting the last layer,then permuting the last layer(OLL and PLL respectively).Fridrichs solution requires learning roughly 120 algorithms but allows the Cube to be solved in only 55 moves on average.Solution

12、s第10页/共26页Speedcubing CompetitionsSpeedcubing(or speedsolving)is the practice of trying to solve a Rubiks Cube in the shortest time possible.There are a number of speedcubing competitions that take place around the world.In addition to official competitions,informal alternative competitions have bee

13、n held which invite participants to solve the Cube in unusual situations.Some such situations include:第11页/共26页Blindfolded solvingSolving the Cube with one person blindfolded and the other person saying what moves to make,known as Team BlindfoldMultiple blindfolded solving,or multi-blind,in which th

14、e contestant solves any number of cubes blindfolded in a row Solving the Cube underwater in a single breathSolving the Cube using a single handSolving the Cube with ones feetSolving the Cube in the fewest possible moves第12页/共26页项目纪录保持者国籍比赛竞速（单次）5.55秒Mats Valk荷兰Zonhoven Open 2013竞速（平均）6.54秒Feliks Zem

15、degs澳洲Melbourne Cube Day 2013盲拧（单次）21.17秒Marcin Kowalczyk波兰PLS Szczecin 2014盲拧（平均）27.51秒Marcin Kowalczyk波兰PLS Szczecin 2014单拧（单次）8.75秒Antoine Cantin加拿大Toronto Fall 2014单拧（平均）11.72秒Feliks Zemdegs澳洲Niddrie 2014Record第13页/共26页项目纪录保持者国籍比赛最少步数（单次）20步Tomoaki Okayama冈山友昭日本Czech Open 2012最少步数（平均）25.00步Sbast

16、ien Auroux德国Velbert Easter Open 2014最少步数（平均）25.00步Vincent Sheu美国US Nationals 2014脚拧（单次）25.14秒Gabriel Pereira Campanha巴西Nova Odessa Open 2014脚拧（平均）30.57秒Gabriel Pereira Campanha巴西Valeparaibano 2013多个盲拧54分14秒复原41个中的41个Marcin Kowalczyk波兰SLS Swierklany 2013第14页/共26页VariationsThere are different variatio

17、ns of Rubiks Cubes with up to seventeen layers:the 222(Pocket/Mini Cube),the standard 333 cube,the 444(Rubiks Revenge/Master Cube),and the 555(Professors Cube),the 666(V-Cube 6),and 777(V-Cube 7).The 171717 Over The Top cube(available late 2011)is currently the largest(and most expensive,costing mor

18、e than a thousand dollars)available.Chinese manufacturer ShengShou has been producing cubes in all sizes from 2x2x2 to 10 x10 x10(as of late 2013).第15页/共26页第16页/共26页ModificationApart form the normal cubes,there are also a large number of original cubes modified by the cubers.Here are some example of DIY cubes.第17页/共26页ModificationPyraminxAlexanders star第18页/共26页MegaminxTuttminx第19页/共26页MirrorHollow Cube第20页/共26页234第21页/共26页Square 1第22页/共26页第23页/共26页第24页/共26页ThanksForListening!第25页/共26页感谢您的观看！第26页/共26页