No experiment today provides evidence that gravity requires a quantum description. The growing ability to achieve quantum optical control over massive solid-state objects may change that situation -- by enabling experiments that directly probe the phenomenology of quantum states of gravitational source masses.
This can lead to experimental outcomes that are inconsistent with the predictions of a purely classical field theory of gravity. Such “quantum Cavendish” experiments require to explore extreme regimes of both quantum and gravity phenomena, specifically: delocalised motional quantum states of sufficiently massive objects, as well as gravity experiments on the microscopic scale. This seminar reviews the current status in the lab and the challenges to be overcome for future experiments.

Looking at the starry sky, several questions come to our mind, such as "What is the Universe made of?", "How was it created?", "What, if anything, happened before the Big Bang?", "How does the Universe evolve and what is its ultimate fate?". To address these puzzling questions, we need a blend of theoretical developments and observational data. This seminar will discuss the observational and experimental tools we have at our disposal, as well as the two pillars of theoretical physics, namely General Relativity and Quantum Mechanics. Our current understanding of the early universe will be discussed, and the need for a fundamental theory, dubbed Quantum Gravity, will be highlighted, in order to resolve the remaining open questions.

International security and peace are very serious concerns in these days full of conflicts and marked by unpredictable political, economic and social changes. The role science can play in such a tensed global scenario is a complex one. Beside the contribution it can give to promoting dialogue and peace, it can also make available knowledge and instruments that may be used to offend, ranging from application of AI for new kinds of armaments to the development of even more destructive nuclear weapons. Since its creation the Pugwash institution, which earned the Nobel Peace Prize in 1995, is very active to “develop and support the use of scientific, evidence-based policymaking, focusing on areas where nuclear and mass destruction weapons risks are present”. Participating remotely via videoconference, Karen Hallberg, the present Secretary General of Pugwash, will present an overview of Pugwash’s action, with focus on the most critical topics the organization is presently dealing with and on the solutions it proposes to reduce global security threats and the danger of armed conflicts. The presentation is in the context of the course “Sciences, diplomacy and policymaking for a sustainable future” given by Maurizio Bona, who will initiate and moderate a dialogue with Karen Hallberg after her presentation, with the participation of the audience.

The study of habitable worlds has become a central focus in modern astrophysics, propelled by the discovery of exoplanets, the search for life beyond Earth, and the quest to understand the conditions necessary for supporting life. This colloquium will provide an overview of the current state of the art in this highly interdisciplinary field, emphasising the intricate balance of factors that determine planetary habitability. Key physical principles such as stellar properties, atmospheric composition, climate dynamics, and the influence of galactic environments will be discussed, along with the methods used to assess and characterize these conditions across a range of exoplanets.

The study of habitable worlds has become a central focus in modern astrophysics, propelled by the discovery of exoplanets, the search for life beyond Earth, and the quest to understand the conditions necessary for supporting life. This colloquium will provide an overview of the current state of the art in this highly interdisciplinary field, emphasising the intricate balance of factors that determine planetary habitability. Key physical principles such as stellar properties, atmospheric composition, climate dynamics, and the influence of galactic environments will be discussed, along with the methods used to assess and characterize these conditions across a range of exoplanets.

FLASH radiotherapy (FLASH-RT) is an innovative cancer treatment that delivers ultra-high dose rates (≥40 Gy/s) in less than 200 ms. This irradiation modality elicits a biological effect called FLASH effect, that significantly reduces damage to normal tissues while maintaining tumor control. Despite promising preclinical results, the precise mechanisms underlying this effect remain unclear, with hypotheses including transient oxygen depletion and reactive oxygen species dynamics. The clinical implementation of FLASH-RT faces challenges such as compact radiation sources, accurate dosimetry and reliable equipment for beam monitoring and delivery. This seminar reviews the latest advancements, technological challenges and future directions for FLASH-RT in clinical practice.