"I think I can safely say that nobody really understands quantum mechanics," said Nobel Prize-winning physicist Richard Feynman. And the notion that this discipline is too complex, counterintuitive, mysterious, almost mystical, persists to this day. The study of the behavior of matter and energy in the microscopic world—atoms, electrons, and photons—celebrates its centenary this year, and the UN has declared 2025 the International Year of Quantum Science and Technology. There is no doubt that it has revolutionized the way we understand research, the world, and geopolitics, but until twenty years ago, there was still reluctance and misunderstanding toward quantum physics within the scientific community itself.

Alba Cervera's (Barcelona, ​​1991) decision to study physics has a lot to do with Star Trek and Isaac Asimov. Her father loved science fiction and instilled that passion in her. Cervera was fascinated by everything related to space and decided she wanted to be an astrophysicist. However, while studying for her physics degree at the University of Barcelona, she discovered quantum information and dedicated herself to it completely. And today she is one of the most recognized scientific voices in that field.

Quantum physics, often perceived as an abstract theory far removed from everyday life, has been one of the most transformative forces of the contemporary world. Since the beginning of the 20th century, this discipline has changed the way we understand reality and has made possible advances such as computers, the internet, and mobile phones. Now, as its application expands into fields such as artificial intelligence and secure communications, quantum physics is once again at the center of scientific and social debate. In this context, Barcelona will host the fourth edition of the City and Science Biennial from November 18 to 23, coinciding this year with the International Year of Quantum Science and Technology. For six days, the Biennial will offer more than 130 activities—80 of them in Barcelona—to bring this scientific revolution closer to the public. The program will take place simultaneously in Barcelona and Madrid, and for the first time will extend to Mexico, within the framework of the Guadalajara International Book Fair (FIL), where Barcelona will be the guest city.

The first time Pol Forn-Díaz heard about quantum information was during a summer course in the Aragonese Pyrenees. He hadn't long finished his degree and was completely fascinated when he heard about it. Antonio Acín, a theoretical physicist at the Institute of Photonic Sciences (ICFO), talking about quantum information. Shortly after, while starting his doctorate in the Netherlands, he met research groups that were applying superconductivity, another topic that interested him, to quantum information. It was a revelation that pushed him to take a leap of faith and launch into research in this entirely new field.

Everything needs a story. It's how humans understand and explain the world. And the best stories are always those of its origins. First there is nothing, and then there is something. It happens with superheroes, with music groups, and, yes, also with scientific theories. The problem is that tracing the exact origin of a theory to identify it as a point in space-time is an activity that contains a good dose of innocence and another of arbitrariness. This is where the power of stories comes into play. The quality of a story is the arbiter that can decide, without any kind of innocence, the instant at which a theory is born.

The development of the quantum mechanics The discovery that began with German physicist Werner Heisenberg's discovery on the island of Heligoland has allowed us to understand how matter works at microscopic scales with an unprecedented degree of precision and detail. And, as always, with understanding comes applications. Surely, as he strolled headlong along the cliffs of that remote island, Heisenberg wasn't thinking about the applications of his quest. He was driven by the pure curiosity to understand nature at its most fundamental level, the intellectual challenge it posed, and, most likely, the ego-sting that represented the possibility of solving a puzzle that Einstein himself was struggling with. But what Heisenberg discovered on that island, and which many other people helped to expand, changed the world. And it did so because it contained the seeds of three types of ideas: scientific ones, which explain how nature works; technological ones, which manipulate matter for practical benefit; and social ones, which redraw the organization of society.

The dining room of the Hotel Métropole in Brussels gave off the usual aroma of morning coffee. The most brilliant minds of the early 20th century gathered around the tables, deep in intense and profound conversations, commenting on and refuting the presentations given the day before during the final session of the Fifth Solvay Conference. This series of meetings between eminent scientists was initiated by the Belgian chemist Ernest Solvay and, since 1911, was dedicated to delving into the most complex problems of physics and chemistry.

Ultra-precise sensors, more secure communications, faster and more powerful computers. These are just a few examples of quantum technologies, an area of technological development that has been advancing rapidly in recent years and is poised to have a highly disruptive impact in the coming decades. There are even some applications already in commercial expansion, such as cryptographic systems and the first quantum computers.

Anna Fontcuberta i Morral's office still smells new. She says she only recently moved in and that some of the furniture is yet to arrive. It's not even been three months since the Catalan physicist reached the top position in the management of the École Polytechnique de Lausanne, better known by its acronym EPFL, one of the world's leading technical universities.