Fastest way to solve a Rubik’s cube

 

TIME REQUIRED
Long (2-4 weeks)

Objective

The goal of this project is to compare different methods for solving Rubik’s Cube. Which method provides the fastest solution?

Introduction

Rubik’s cube is an interesting 3-dimensional puzzle that challenges your spatial imagination and memory. The goal is to arrange the cube so that each side is a solid color, as shown in Figure 1.

Diagram of all sides of a rubiks cube
Figure 1. Diagram of a solved Rubik’s cube. The six sides are named in pairs—up-down, front-back, and left-right. The up (U), front (F), and right (R) sides are visible. The remaining sides—left (L), back (B), and down (D)—are shown by the projected images.

Figure 1 also shows the labels we will be using when referring to sides of the cube. The six sides are named in pairs—up-down, front-back, and left-right. To refer to a specific side, we’ll use the one-letter abbreviations shown in Figure 1 (U, D, F, B, L, R).

The cube is built in such a way that each side, row, and column can rotate (see Figure 2). With a few turns, the colors can be thoroughly mixed up. How can you get all of the squares back to their original positions? It’s quite a puzzle to get the colors arranged properly again!

Diagram of the core of a Rubik's cube
Figure 2. Diagram of the core of a Rubik’s cube. The core enables each side, row, and column of the cube to rotate.

In this project you will do background research for at least two different methods of solving a Rubik’s cube, and then find out which method works the fastest

Before you start learning Rubik’s cube strategies, you need to be familiar with some basic terminology. A Rubik’s cube is made of three different types of pieces. We will refer to them as center, corner, and edge pieces. The puzzle has six center pieces, one in the middle of each face. Each center piece has only one visible face. There are eight corner pieces on the puzzle. Each corner piece has three visible faces. The remaining twelve pieces are edge pieces, occupying the middle position along each edge of the cube. Each edge piece has two visible faces.

Center Piece Corner Piece Edge Piece
location
Center piece of the Rubiks cube is different
Corner pieces of the Rubiks cube is different
Top, left, right, and middle pieces of the Rubiks cube is different
# in entire cube 6 8 12
visible faces 1 3 2

For each step in solving the cube, specific sequences of moves come in handy. In order to summarize the move sequences efficiently, we will use a shorthand notation common among Rubik’s cube solvers. The shorthand notation is easy to learn. There are just two rules you need to know.

  1. When a side is rotated clockwise one quarter turn, the shorthand notation for the move is simply the letter of the side. For example, if you’re supposed to rotate the right side one quarter turn clockwise, the shorthand would be R.
  2. When a side is rotated counterclockwise one quarter turn, the shorthand notation for the move is the letter + an apostrophe (‘). For example, if you’re supposed to rotate the right side counterclockwise one quarter turn, the shorthand would be R’.

Now that you are familiar with the basic terminology used to refer to a Rubik’s cube, you can start researching different solution methods. You can use the resources in the Bibliography below to get you started, but you should be able to find many more Rubik’s cube resources online.