★This book presents the history of geometry, from ancient Greek mathematicians to the mathematical revolution of the 19th century.
★Geometry is not just an abstract world. The history of geometry is closely intertwined with the history of mathematics, physics, and science, as well as the history of humanity.
★This book opens up new perspectives and allows us to portray the world around us in a better way.

The word geometry evokes triangles and circumferences, areas, perimeters and above all the Pythagorean Theorem. For many, geometry is an abstract world carved in stone more than two millennia ago by Greek mathematicians such as Euclid or Archimedes.
Before the Greeks, however, it had been used for millennia by various different civilizations. And after the Greeks, it evolved enormously. The great classical problems, the squaring of the circle and Euclid's fifth postulate literally haunted mathematicians for two millennia before they were answered. And in the search for answers to these classical questions, geometry has changed and new areas of mathematics have emerged. We went from "The Geometry," the only true one, of which we are certain thanks to logic, to a much more varied landscape, throbbing with different geometries.
In the nineteenth century, the certainties of mathematics collapsed and its foundations were rewritten. Klein gives a new description of geometry, and Hilbert completely overturns the concept of mathematical truth. These were mathematical revolutions that would revolutionize physics in the early twentieth century, opening the way to Einstein's relativity and quantum mechanics.
The history of geometry, of its identity crisis, of its being one, none and a hundred thousand, is closely intertwined with the history of mathematics, physics, science and ultimately with the history of the culture of which we are all a part. This essay opens for us a glimpse, capable of accompanying us in depth, into the architecture of a thought that always better describes the Universe around us.

ALBERTO SARACCO, popularizer, teaches geometry at the University of Parma. He curates the popular YouTube channel "Alberto Saracco" and the Instagram page "A mathematician lent to Disney." He is the author of "Euler's Theorem on Graphs," a volume attached to Le Scienze in August 2023. In 2017, he co-wrote the Disney math-themed story "Donald Duck and The Bridges of Quackenberg" that came out in Mickey Mouse.