The problem of the sofa

The problem of the sofa
Imagine a corridor with a corner let's say that the corridor is one meter in diameter on each side, then a sofa of one meter by one meter should fit easily and then turn and go its way, but now imagine that the sofa measures one meter by two meters, at first it enters but then it can not turn, do you understand? Can you then increase the sofa area by one meter by one meter? Well, if the record has Joseph Gerver in 1992, his area is 2.2195. Then I'll leave you a gif of how he did it.

Rubik's cube

Rubik's cube

It may seem like a simple cube but it has more mathematics than you think to start with there are 43,252,003,274,489,856,000 possible positions in the cube 3 * 3 imagine how many possible positions there are in the 4 * 4 or higher there is also the number of god that consists of the minimum of movements in which you can solve a cube of rubik before this number was 52 but recently updated to 20 ¿incredible, no? in any position with only 20 movements can be resolved.There are also many maths in trying to solve the rubik's cube because you have to know where to start, the theory of the cube and also some algorithms to make special things happen in the cube.