Discovery of Cosmic Fractals

A presentation of results on the largest fractal structures in the universe. It seeks to guide the reader, in a simple way, to the frontiers of astronomy, explaining how fractals appear in cosmic physics, from our solar system to the megafractals in deep space. It also offers a personal view of the history of the idea of self-similarity and of cosmological principles, from Plato's ideal architecture of the heavens to Mandelbrot's fractals in the modern physical cosmos. In addition, it discusses the great fractal debate in astronomy (after Luciano Pietronero's first fractal analysis of the galaxy universe), which illustrates how new concepts and deeper observations reveal unexpected aspects of nature.