英語課課前演講《魔方(Rubic's-Cube)》

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 mak

2、ing it the worlds top-selling puzzle game. It is widely considered to be the worlds best-selling toy.IntroductionRubiks Cube is a was invented by the Hungarian architect Ern Rubik.InventorIn the mid-1970s, Ern Rubik worked at the Department of Interior Design at the Academy of Applied Arts and Craft

3、s 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 whic

4、h shows the beauty of architecture.InventionsStructureThe 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 three

5、colored faces. Each piece shows a unique color combination, but not all combinations are present.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) possibilities.

6、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 centers are also permitted, as described below, the rule is that the combined arrangement of corners, edges, and centers must be an

7、 even permutation.) Eleven edges can be flipped independently, with the flip of the twelfth depending on the preceding ones, giving 211 (2,048) possibilities. MathematicsSolutionsAlthough there are a significant number of possible permutations for the Rubiks Cube, a number of solutions have been dev

8、eloped which allow solving the cube in well under 100 moves.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 layer, in which

9、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.SolutionsA solution commonly used by speed cubers was developed by Jessica Fridrich. It is sim

10、ilar to the layer-by-layer method but employs the use of a large number of algorithms, especially for orienting and permuting the last layer. SolutionsThe cross is done first, followed by first layer corners and second layer edges simultaneously, with each corner paired up with a second-layer edge p

11、iece, 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.SolutionsSpeedcubing

12、 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 been held which invi

13、te participants to solve the Cube in unusual situations. Some such situations include: Blindfolded solving Solving the Cube with one person blindfolded and the other person saying what moves to make, known as Team Blindfold Multiple blindfolded solving, or multi-blind, in which the contestant solves

14、 any number of cubes blindfolded in a row Solving the Cube underwater in a single breath Solving the Cube using a single hand Solving the Cube with ones feet Solving the Cube in the fewest possible moves項(xiàng)目項(xiàng)目紀(jì)錄紀(jì)錄保持者保持者國(guó)籍國(guó)籍比賽比賽競(jìng)速（單次）競(jìng)速（單次）5.55秒秒Mats Valk荷蘭荷蘭Zonhoven Open 2013競(jìng)速（平均）競(jìng)速（平均）6.54秒秒Feliks Z

15、emdegs澳洲澳洲Melbourne Cube Day 2013盲擰（單次）盲擰（單次）21.17秒秒Marcin Kowalczyk波蘭波蘭PLS Szczecin 2014盲擰（平均）盲擰（平均）27.51秒秒Marcin Kowalczyk波蘭波蘭PLS Szczecin 2014單擰單擰（單次）（單次）8.75秒秒Antoine Cantin加拿大加拿大Toronto Fall 2014單擰單擰（平均）（平均）11.72秒秒Feliks Zemdegs澳洲澳洲Niddrie 2014Record項(xiàng)目項(xiàng)目紀(jì)錄紀(jì)錄保持者保持者國(guó)籍國(guó)籍比賽比賽最少步最少步數(shù)數(shù)（單次）單次）20步步Tomo

16、aki Okayama岡岡山友昭山友昭日本日本Czech Open 2012最少步最少步數(shù)數(shù)（平均）平均）25.00步步Sbastien Auroux德國(guó)德國(guó)Velbert Easter Open 2014最少步最少步數(shù)數(shù)（平均）平均）25.00步步Vincent Sheu美國(guó)美國(guó)US Nationals 2014腳擰（單次腳擰（單次）25.14秒秒Gabriel Pereira Campanha巴西巴西Nova Odessa Open 2014腳擰（腳擰（平均）平均）30.57秒秒Gabriel Pereira Campanha巴西巴西Valeparaibano 2013多個(gè)盲多個(gè)盲擰擰54

17、分分14秒秒復(fù)原復(fù)原41個(gè)個(gè)中的中的41個(gè)個(gè)Marcin Kowalczyk波蘭波蘭SLS Swierklany 2013VariationsThere are different variations 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 more than a thousand dollars) available. Chinese manufacturer ShengShou has been producing cubes in all sizes from 2x2x