The Rubik

1
The Rubiks Cube

• What theyre really about

2
Standard 3 x 3 Cube

• The 3x3 cube is the most common of all Rubiks
  cubes.
• The world record for the fastest ever solve is
  7.08 seconds, by Erik Akkersdijk.
• The cube is solved using algorithms, rather than
  skill, it is remembering that helps the
  solution.

3
The Cube Algorithms

• The notation Up U Down D
• Right R Left L
• Front F Back B
• Vertical Middle Y
• Horizontal Middle X
• Vertical Horizontal Z
• A?1 Anticlockwise turn 90 (Where A any
  letter above)
• Example In this example,
• RR ?1 1, so no change is made

4
Edge 3-Cycles

• It is a necessity to know these to be able to
  solve a Rubiks cube. They usually involve cyclic
  permutations of 3 edges. Repeating the same cycle
  three times will return the cube to the original
  state.
• E.g RU?1R?1YRUR?1Y?1
• Represents Cw Right, Acw Upper, Acw Right, Cw
  Upper Middle, Cw Right, Cw Upper, Acw Right, Acw
  Upper Middle.

5
Edge 3-Cycles

• Or, in a picture form, represents the
  translation
• This is a common method of switching specific
  pieces to specific places, as seen in the
  diagram. (The edges are cycled)

6
Edge 3-Cycles

• Another two cycles are
• RU?1R?1YYRUR?1YY
• RU?1R?1Y?1RUR?1Y
• Can you work out which cycle matches which
  diagram?

1
2
7
Corner Cycles

• A corner cycle is the process of moving two
  corner pieces into different corners without
  disrupting the state of the cube
• Although moving pieces for corner to corner seems
  much simpler logically, mathematically, it is a
  much more complex cycle.
• Similarly, repeating the cycle three times will
  return the cube to the original state.

8
Corner Cycles

• The first example of a Corner Cycle is
• FRF?1LFR?1F?1L?1
• Can you translate this from Group Notation into
  the separate turns required?
• Note Although there are several Corner Cycles,
  it is possible to solve a Rubiks cube knowing
  only the one above.

9
Rubiks Cube World Domination

• Using the total 43,252,003,274,489,856,000
  permutations of a cube (Different positions), and
  then lining these permutations up, with an
  average 57mm cube, there would be enough cubes to
  cover the earth with 273 layers of Rubiks cube.
• This is true even after the
• 57mm thickness of each
• cube has been taken into
• account !

10
The End

• Using the information in this presentation, you
  should now be able to solve the basics of a
  Rubiks cube.
• Remember It is a problem that requires the
  memory of algorithms, not skill!