I would like to offer one simple experiment. It can be repeated by everyone. I am interested in conclusions which it is possible to make of this experiment. In my opinion, a correct conclusions can have the important consequences. So. Two flat mirrors are located in parallel on distance 1 meter (this distance is not critical). Between them approximately in the middle some object is located. Better if it is a light source . The point of observation, where your head is located also between mirrors, but is higher than object.. Now, we look at the mirrors. The result of observation: An infinite line of images of this object in both mirrors. This line of images has prospect. Why?