Can we “see” photons, black holes, curved spacetime, quantum jumps, the expansion of the universe, or quanta of space? Physics challenges appearances, showing convincingly that our everyday vision of reality is limited, approximate and badly incomplete. Established theories such as quantum theory and general relativity and investigations like loop quantum gravity have a reputation of obscurity. Many suggest that science is forcing us into a counterintuitive and purely mathematical understanding of reality. I disagree. I think that there is a visionary core at the root of the best science. Where “visionary” truly means formed by visual images. Our mind, even when dealing with abstract and difficult notions, relies on images, metaphors and, ultimately, vision. Contrary to what is sometimes claimed, science is not just about making predictions: it is about understanding, and, for this, developing new eyes to see. I shall illustrate this point with some concrete cases, including the birth of quantum theory in Einstein’s intuition, curved spacetimes, and quanta of space.
Carlo Rovelli is a theoretical physicist, known for the development Loop Quantum Gravity, his work on the nature of physical time and the Relational Interpretation of quantum mechanics. He was born in Italy in 1956, has studied in Bologna and Padova and has worked in several Universities in Italy and the United States; he is currently directing the Quantum Gravity group of the Centre de Physique Théorique of the University of Aix-Marseille. He has honorary degrees from Beijing Normal University, and the Universidad de San Martin of Buenos Aires, Argentina. He is a member of the International Academy for the Philosophy of Science, of the Institut Universitaire de France and of the Accademia Galileana. He has written successful popular science books: his “Seven Brief Lessons on Physics” is translated in 41 languages and has sold over a million copies. His most recent book, The Order of Time, is on the nature of time.