Sunday, April 22, 2007

0 - The Rubik Cube

The Rubik's Cube is a puzzle invented in 1974 by the Hungarian Ernő Rubik. Originally called the "Magic Cube", it was licensed to Ideal Toys in 1980 and won the German award for Best Puzzle of 1980.

Before start solving the Rubik Cube, here are some basics, hints and tips.

The cube has 6 faces, with 6 colors, and 3 kinds of pieces:
- Corner pieces (3 colorful sides);
- Middle pieces (2 colorful sides);
- Axis pieces (only 1 colorful side);

A corner piece can never be moved to the place of a middle or axis piece.
A middle piece can never be moved to the place of a corner or axis piece.
Axis pieces can not be moved (only rotate). They define the face color.

So, if you are trying to fix one face of the cube, remember to check if all the pieces are in the correct position, according to the other axis (faces) colors.

We will solve the cube following a small number of steps, that you have to memorize. Each step is made of several movements that change some pieces in the cube, without breaking what was done before.

1 - Solving the first layer

For this step, there is no magic trick. Just do your best to have one layer solved, with the correct colors on the top and on the side. Is the hardest part for the beginner, but once you played enough with the cube, this will be the easiest part. This step does not have an Algorithm to help solving, but some tricks that  may speed it up. Here they are:

1-choose_color1 - Select a face to be your top face, and keep it!
Many of the steps involve moving the cube, but never forget your top face/color (In the example, we start with the white face).

As we know, the central pieces (that never move) define the color of the face, so the top face is white and the other side faces are orange and yellow in the picture.

21-make_cross 2 - Make a cross.
Find the pieces you need, and move them one by one to the right position.

The cross is made with the central pieces (pieces with 2-sides only), and every piece should be correctly placed (for instance, the blue side aligned with the blue face, the white side aligned with the white face).

3 - Place the edge pieces.
Now, find the edge piece (3-color piece) that has the 3 colors for the corresponding edge, and move it to his place. Repeat for each of the 4 edges and TA-DÁ, you have your top face (white) solved, plus the first layer (blue, orange) of the cube is done!

Here you can try a small trick, instead of placing the edge on top, move the piece you want to switch down to the last layer, and change it there, then moving it back to the top layer.

Here is a small video showing how to do the first layer with this last trick.

After succeeding, repeat this step exhaustively, till you learn it…
And Good Cubing!

2 - Solving the Second Layer

After learning to complete the First Layer of Rubik Cube, it's time to complete the Second Layer, where each face has a fixed piece, so we only have to position 4 middle pieces (2-color pieces) without breaking what's done. For this step, there is an algorithm, but after you study it a little, it is a very logical way of reorganizing the pieces without breaking the current order (first layer).

0 - Start by putting the piece under the matching color;

1 - Move the piece row in the opposite direction of the final place;
2 - Move the column of the final place down;
3 - Move the piece row back to the starting position;
4 - Move the column of the final place back to starting position;

5 - Move the piece row in to the opposite direction of step 2;
6 - Move the column of the final place down;
7 - Move the piece row back to the starting position;
8 - move the column of the final place back to starting position;

Here is a small video where the second layer is solved.

Add your questions to the comments, and Good Cubing!

3 - Making a Cross in the last layer

Coming Soon!

4 - Positioning the corner pieces

Coming soon!

5 - Fixing the corner pieces color

Coming Soon!

6 - Fixing the last central pieces

Coming Soon