Rubik’s cube

Sally follows you into your high-ceilinged office crammed with books and electrical equipment. Lying scattered between the sofa and chairs are three oscilloscopes, a tall Indian rubber plant, and a Rubik s cube. A small blackboard hangs on the wall. The bulletproof, floor-to-ceiling windows give the appearance of a room more spacious than it really is. Sally eyes the electrical hardware. What s all this ... 

You trip over a Rubik s cube that you had left on the floor and bump into Sally s chair. 

Many of you will be familiar with Erno Rubik s ingenious cubical puzzle and its variations that include a 4 X 4 X 4 cube and puzzles shaped like tetrahedra. One natural variation that never appeared on toy store shelves is the 4-D version of Rubik s cube—Rubik s tesseract. Dan Velleman (Amherst College)... 

Figure A.l A 3 x 3 x 3 Rubik s cube dissected into three 3X3 layers.

Or, for those that remember the Rubik s cube craze of the early 1980s, if everyone on earth spent at least 3 h/day making random moves on shuffled Rubik s cubes, making about one move every second (if you do remember the early 1980s you may feel that it did indeed seem like that at the height of the craze), we should expect a report of chance success about every century. 

Purveslab at the Center for Cognitive Neuroscience, Duke University, has published numerous papers on the psychophysical visual effects people experience. One of the most striking examples of how the eye perceives colour in context is described by Lotto and Purves (2000). The discs, described in this paper, are similar to the two cubes with coloured squares (similar to a Rubik s cube) shown on the laboratory s website (Purveslab, 2011). The two cubes look similar, but one is shown in a blue environment, while the other one is shown in a yellow environment. The darkest squares of the cube in the yellow environment are blue. Yellow is the second-lightest colour of the cube in the blue environment. But, when the above-mentioned blue and yellow squares are isolated from their respective environments (taken out of context), all of them have the same colour The reason for this is called colour contrast. Although the spectral returns from the said squares are the same, the perception is that they exist in environments with different illumination, and therefore they elicit different colour stimuli in the brain. Camouflage patterns, with colours exhibiting this kind of behaviour, are effective in a wide range of environments. 

Researchers in the field of analysis generally refer to this as three-dimensional data (my company is no exception), but more accurately, it is a three-dimensional representation of two-dimensional data. Because three-dimensional data result in a block data stmcture (suggestive of the Rubik s cube), it is difficult to represent these data in a single diagram, and thus, data compilation techniques such as slicing the data parallel to each facet are necessary. 

Batteries design can be compared in view of the three main components the electrode A, the electrolyte, and the electrode B. A possible battery classification can be deduced from the nature of these components liquid, soft or solid. This is the figure of the Rubik s cube shown in Fig. 1.6 [13]. All these media can be liquid, plastic (soft) or solid. This is crucial because certain interfaces are difficult to handle. Common batteries have a solid-liquid-solid configuration the liquid— solid-liquid system corresponds to the Na-S battery using p-alumina as the electrolyte, which permits relatively easy manufacture. On the other side, the aU-soUd... 

Fig. 1.6 Rubik s cube showing the association of the three components in the solid, soft, and liquid state of electrochemical cells. Reproduced with permission from [13]. Copyright 1994 Wiley...

Many of you will be familiar with Erno Rubik s ingenious, colorful 3X3X3 cubical puzzle (Fig. A.l). Each face is a 3 X 3 arrangement of small cubes called cubies. If you were to cut this cube into three layers, each layer would look like a 3X3 square with the same four colors appearing along its sides. Two additional colors are in the interiors of all the squares in the first and third layers. (These are the colors on the bottom of all the squares in the first layer and top of all the squares in the third layer.)... 

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