L’ultimo orizzonte. Cosa sappiamo dell’universo

What do we know about the universe? A lot—an incredible amount, in fact. We know its age, its structure, what it contains, and how it has evolved into a vast expanse filled with galaxies, stars, and planets. Just over a century ago, we knew almost nothing about any of this.
The story of how modern physics has advanced so far in understanding the cosmos is a tale of an extraordinary scientific adventure—one that astrophysicist and science communicator Amedeo Balbi guides us through step by step. From Einstein’s theory of relativity to the discovery of the universe’s expansion, from the observation of the cosmic microwave background to the development of the “classical” Big Bang model—now considered the best description of the universe’s origin—each milestone has shaped our current knowledge.
So, have we figured out everything about the universe? Of course not. While we are confident in the broad framework, we certainly haven’t defined every detail. Balbi takes us to the frontier of current research, from confirming the theory of cosmic inflation to the search for dark matter and the mystery behind the accelerating expansion of the universe. Yet even at the cutting edge of discovery, we remain far from answering some of the most fundamental questions: Is the universe finite or infinite? Did space and time have a beginning, and will they have an end? Could the laws of nature have been different? Are there other universes beyond our own?
To tackle these questions with the tools of science, we must push beyond the last horizon—where the events of the universe’s infancy are hidden behind a wall of fire, where our measurements of the cosmos may no longer apply, and where we might discover that our physics describes only a fleeting moment and a tiny portion of a much larger, unreachable reality. What do we know about the universe?