STILL UNDER CONSTRUCTION!!
The Rubik’s cube has kept a generous handful from our generation and the previous busy. The record time in solving it is 6.something seconds. Some solve it blindfolded in a remarkably short period of time too. Then there are variations of 5 x 5 and higher cubes. Two minutes sounds like no extraordinary feat, but its a start. So, if you’ve ever held one in your hand and wondered ‘how do they do it’, here’s a push in the right direction
There are many sources on the internet that provide algorithms.. www.rubiks.com/ or http://www.youtube.com/watch?v=HsQIoPyfQzM which I have learnt from.
I recommend the following according to which I believe an average person could solve the cube under 2 minutes with 3-4 weeks of practice. You’ll need to learn just 5-6 short algorithms. Once you get a hang of how to solve it, it’s just a matter of a little more practice to attain enough speed. It’s really quite simple !!
Types of pieces:
1- Center: they lie at the centre of each face. They are immovable and define the colour of their respective faces. There are 6 such pieces.
2-Corner: lying at the (no points for guessing) corners, they have 3 sides and hence 3 colours. There are 6 such pieces.
3-Edge: the pieces not included in centre and corner. ( The name is not very accurate). They have 2 sides and hence 2 colours.There are 12 such pieces.
Moving the pieces around:
Let the face towards you be the front. Rotating this piece through 90* in the clockwise direction is depicted as F. Rotating the piece in the anti-clockwise direction is donated by F’. F = front U = up R = right L = left D = down
F’= front inverse U’=up inverse R’= right inverse L’= left inverse D’= down inverse
Don’t get confused as R means rotating the right face away from you but L means rotating the left face towards you, because the pieces are rotated with respect to the clockwise or anticlockwise direction for that particular face only. Also, do not change the selected front face in between an algorithm.
Lets get started
One method of solving the cube is the layer method, a top- down approach, where you start with solving the top layer (U) , then the middle and lastly the bottom layer. Each piece has it’s own unique position.
I suggest you try solving the top layer on your own- it may seem impossible at first and take a lot of time, but dont be disheartened. Use your grey matter abit in the beginning, and you can learn the tricks later.
I prefer first solving the centre cross ( + ) i.e., once you chose your first side, get the correct edge pieces into place. For example, the edge piece coloured red and white must lie with the white on the white’s side ( i.e. the side with the white centre cube) and the red on the red’s side only.
Once you have the + in place, you can start with the corners- without disturbing what you’ve already solved (that’s the tough part) . As mentioned before, the corner piece is 3 sided and each piece has it’s unique position- so you have to get all 3 colours correct.
Algorithm for the 1st layer is available on the sites I mentioned earlier- but it’ll be better if you struggle with it on your own. Once you’re done with the 1st layer, most of the hard work is done- the rest can be solved very easily with the algorithm mentioned below.
Once your first layer is in place, position the cube such that F faces you. As you can see, the centre piece and top layer of each face is solved. For the second layer all you have to worry about are the 4 edge pieces. Bring the pieces into position as shown, where i is the initial position depicted where your piece first is and f is the final position depicting where that piece has to go. First get the ” T” – the required edge piece has to be positioned in such a manner that pieces of the same colour form a “T”. The piece that we will now work on is the edge piece in the lowest layer of the front face. If this piece needs to move to the middle left, follow algorithm 1, if it needs to move to the right follow algorithm 2.
Algo 1: D L D’ L’ D’ F’ D F
Algo 2: D’ R’ D R D F D’ F’
As you can see, algo 2 is just the opposite of algo 1…so just remember the 1st and work your way through the 2nd doing the opposite.
You’ve got 1 edge piece in place, 4 more to go – follow the same steps. You may get stuck if you have no edge piece in the correct positions in the lower layer- they are probably already in the middle layer. If they are in the correct position, you are good to go…but if they aren’t, all you’ve got to do is bring them using the algo1/2 to bring them down by sending a dummy piece up. You’ll soon be done with the middle layer following these steps.
The Lowest layer
Turn the cube over such that you have the unsolved layer on the top i.e. U .
1) The first step is to get the cross ( + ) .You start with getting the colours on top- Algo 3 and then getting the pieces in the correct place – Algo 4.
i) Getting the correct colour on top (here, the pieces will not be in the correct position)
Algo 3: F R U R’ U’ F’
If the the pieces with the correct colour on top form a) an L shape, then hold the cube in such a manner that that the L is vertically inverted b) a line, hold the cube such that the line is along the horizontal (i.e. x axis)…or you’ll be stuck in a loop
ii)Getting the pieces in the correct position
Algo 4: R U R’ U R U U R’
Rotate the top such that two edge pieces are in the correct position. Hold the cube in such a manner that the edge pieces that are correct lie on the front and back OR right and back face.
Once this is done, your cross should be complete. An easy way to remember these is as a word itself: fru-ri-ui-fi , ruri-u- ruuri
2) The final bit- correcting the corners. Here you start with getting all the pieces in the right place (algo 5) and then flipping then the right side 9algo 6)
i) Getting the corners in the right place
algo 5) U R U’ L’ U R’ U’ L
Instead of learning this algorithm, remember it as follows:
up, away from you (right), up inverse, away from you (left), up , towards you (right), up inverse, towards you (left)
While doing the above , make sure that you hold the cube such that one corner which is in the correct position is always in the bottom right of the top face. If no corner is in the correct position, hold the cube any way- but once a corner is in the correct position- hold it as described. Repeat the above till all the corners are in the correct position- but not necessarily flipped the correct side.
ii) Flipping the corners
algo 6: R’ D’ R D
Here, do the opposite- hold the cube in such a manner that the corner that needs to be flipped is in the bottom right of the top face. To flip one piece, this algo needs to be repeated till it is flipped correctly- you may need to repeat it 1-6 times.
This step totally messes up the cube- even what has been previously solved- do not worry, by the last move everything will fall into place
Once one corner is done- keeping the front face the same (which is extremely important), rotate the top so the the next incorrect piece is nin the bottom right of the top face. If you make a mistake in a single step, the whole thing goes wrong.Repeat the above till all corners are flpped correctly.
Congratulations! Your cube is now solved.