I was fascinated by the research field of one of my professors, Guy Demortier. He was working on the characterization of antique jewelry. He had found a way to differentiate by PIXE (Proton Induced X-ray Emission) analysis between antique and modern brazes that contained Cadmium, the presence of this element in antique jewelry being controversial at the time. He was interested in ancient soldering methods in general, and the granulation technique in particular. He studied them at the Laboratoire d'Analyses par Réaction Nucléaires (LARN). Brazing is an assembly operation involving the fusion of a filler metal (e.g. copper- or silver-based) without melting the base metal. This phenomenon allows a liquid metal to penetrate first by capillary action and then by diffusion at the interface of the metals to be joined, making the junction permanent after solidification. Among the jewels of antiquity, we find brazes made with incredible precision, the ancient techniques are fascinating.

In fact, this was one of Namur's fields of research at the time: heritage sciences. Professor Demortier was conducting studies on a variety of jewels, but those made by the Etruscans using the so-called granulation technique, which first appeared in Eturia in the 8th century BC, are particularly incredible. It consists of depositing hundreds of tiny gold granules, up to two-tenths of a millimeter in diameter, on the surface to be decorated, and then soldering them onto the jewel without altering its fineness. So I also trained in brazing techniques and physical metallurgy.

I applied for a position as a physicist at CERN in the field of vacuum and thin films, but was invited for the position of head of the vacuum brazing department. This department is very important for CERN as it studies methods for assembling particularly delicate and precise parts for accelerators. It also manufactures prototypes and often one-off parts. Broadly speaking, vacuum brazing is the same technique as the one we study at Namur, except that it is carried out in a vacuum chamber. This means no oxidation, perfect wetting of the brazing alloys on the parts to be assembled, and very precise temperature control to obtain very precise assemblies (we're talking microns!). I'd never heard of vacuum brazing, but my experience of Etruscan brazing, metallurgy and my background in applied physics as taught at Namur were of particular interest to the selection committee. They hired me right away!

CERN is primarily known for hosting particle accelerators, including the famous LHC (Large Hadron Collider), a 27 km circumference accelerator buried some 100 m underground, which accelerates particles to 99.9999991% of the speed of light! CERN's research focuses on technology and innovation in many fields: nuclear physics, cosmic rays and cloud formation, antimatter research, the search for rare phenomena (such as the Higgs boson) and a contribution to neutrino research. It is also the birthplace of the World Wide Web (WWW). There are also projects in healthcare, medicine and partnerships with industry.

For my part, in addition to developing vacuum brazing methods, a field in which I've worked for over 20 years, I've worked a lot in parallel for the CLOUD experiment. For over 10 years, and until recently, I was its Technical Coordinator. CLOUD is a small but fascinating experiment at CERN which studies cloud formation and uses a particle beam to reproduce atomic bombardment in the laboratory in the manner of galactic radiation in our atmosphere. Using an ultra-clean 26 m³ cloud chamber, precise gas injection systems, electric fields, UV light systems and multiple detectors, we reproduce and study the Earth's atmosphere to understand whether galactic rays can indeed influence climate. This experiment calls on various fields of applied physics, and my background at UNamur has helped me once again.

I was also responsible for CERN's MACHINA project -Movable Accelerator for Cultural Heritage In situ Non-destructive Analysis - carried out in collaboration with the Istituto Nazionale di Fisica Nucleare (INFN), Florence section - Italy. Together, we have created the first portable proton accelerator for in-situ, non-destructive analysis in heritage science. MACHINA is soon to be used at the OPD (Opificio delle Pietre Dure), one of the oldest and most prestigious art restoration centers, also in Florence. The accelerator is also destined to travel to other museums or restoration centers.

ELISA uses the same accelerator cavity as MACHINA. The public can observe a proton beam extracted just a few centimetres from their eyes. Demonstrations are organized to show various physical phenomena, such as light production in gases or beam deflection with dipoles or quadrupoles, for example. The PIXE analysis method is also presented. ELISA is also a high-performance accelerator that we use for research projects in the field of heritage and others such as thin films, which are used extensively at CERN. The special feature is that the scientists who come to work with us do so in front of the public!

I remember that in 1989, I finished typing my report for my IRSIA fellowship in the middle of the night, the day before the deadline. It had to be in by midnight the next day. There were very few computers back then, so I typed my report at the last minute on one of the secretaries' Macs. One false move and pow! all my data was gone - big panic! The next day, the secretary helped me restore my file, we printed out the document and I dropped it straight into the mailbox in Brussels, where I arrived after 11pm, in extremis, because at midnight, someone had come to close the mailbox. Fortunately, technology has come a long way since then...

And I can't resist sharing two images 35 years apart!

To the left, a Gold statuette (Egypt), c. 2000 BC, analyzed at LARN - UNamur (photo 1990) and to the right, a copy (in Brass) of the Dame de Brassempouy, analyzed with ELISA - CERN (2025).

The "photographer" is the same, so we've come full circle...

The proximity between teaching and research inspires and questions. This enables graduate students to move into multiple areas of working life.

Come and study in Namur!

Serge Mathot (May 2025) - Interview by Karin Derochette

• The CERN accelerators complex
• The Science Portal, CERN's public education and communication center
• Omalius Alumni article (September 2022): François Briard

In late October, Rector Annick Castiaux, accompanied by Vice-Rector for International Relations and Cooperation Stéphane Leyens, visited Université Savoie Mont Blanc. The aim: to identify opportunities for bilateral collaboration between the two institutions.

Professors Denis Saint-Amand (Faculty of Philosophy and Letters, President of the Namur Institute of Language and Transmediality) and Johan Yans (Director of the Department of Geology and President of the Institute of Life,Earth and Environment) were also part of the UNamur delegation. Université Savoie Mont Blanc was represented by its President, Philippe Briand, as well as Mareva Sabatier (Vice-President of the Board of Directors, in charge of personnel), Pascal Hot (Vice-President in charge of research) and Emilie Viret-Thasiniphone (Director of International Relations).

Meetings were held with representatives from various institutes and laboratories: mathematics, physics, earth science and geology, business administration, literature. Opportunities for collaboration in these fields were discussed.

The RELIEF Network (Réseau d'Échanges et de Liaisons entre Institutions d'Enseignement Supérieur Francophones) brings together four universities: the UNamur, the Université Savoie Mont Blanc, the Université du Québec à Trois-Rivières (UQTR) as well as the Haute École Spécialisée de Suisse Occidentale (HES-SO).

Created in 2015, the RELIEF network aims to:

• Foster exchanges and interactions between partner institutions;
• Develop high-quality joint projects on an international scale, particularly in the French-speaking world, for students and teacher-researchers;
• Strengthen the visibility and impact of initiatives carried out by the network and its members.

Invited to join RELIEF in 2025, UNamur looks forward to this integration.

Olivier Sartenaer's team: Doan Vu Duc, Maxime Hilbert, Charly Mobers, Olivier Sartenaer, Louis Halflants, Andrea Roselli, Gauvain Leconte-Chevillard, Eve-Aline Dubois.

"Several contingent factors enabled the creation of SPiN: the absence of a research structure specifically dedicated to these themes and the almost simultaneous arrival of four young philosophers of science. It's a bit like an alignment of the planets", explains Olivier Sartenaer.

At his side are Juliette Ferry-Danini (Faculty of Computer Science), Thibaut De Meyer (Faculty of Philosophy and Letters) and Gaëlle Pontarotti (Faculty of Science), who form the core of SPiN.

SPiN is part of a research dynamic committed to the heart of contemporary debates.

SPiN researchers explore a wide range of themes, against a backdrop of questioning our relationship to scientific knowledge. These include:

• the relationship between science and pseudoscience;
• reductionism in science;
• genetic determinism and heredity;
• medical ethics and public health (vaccinations, pandemics);
• ethology,
• perspectivism.

This research is carried out by an interdisciplinary team of teacher-researchers, doctoral students and post-docs from the various faculties of UNamur.

SPiN organizes weekly seminars devoted to current research in philosophy of science, as well as seminars linked to more specific themes: health, life sciences, cosmology and theories of emergence and reductionism in the natural sciences.

But SPiN is not limited to the academic sphere: the center intends to take these issues outside the university walls, through events and activities accessible to all. An inaugural event is already planned for next spring on a topical theme: mistrust in science. More info to come!

Democracy is by no means a fixed concept. It is the subject of debate, especially today. Louis Carré, Director of the Department of Philosophy and member of the Espace philosophique de Namur (Institut ESPHIN), proposes a three-dimensional definition: a political regime, a state of law and a way of forming society.

"Etymologically, democracy is a political regime that consists in giving power to the people," he reminds us. "Our Western democracies today are based on the idea that the people are sovereign, without governing directly. From this arises a tension between ideal democracy and real democracy."Vincent Jacquet, professor in the Department of Social, Political and Communication Sciences and president of the Transitions Institute supports the point: "Democracy is an ideal of citizen self-government, but it is in tension with more centralizing, authoritarian logics. [...] Our political systems are crisscrossed by these different tensions, with both authoritarian logics increasingly present, including in our own country, and logics of participation that are sometimes accompanied by a great deal of hope and disappointment too."

The second pillar according to Louis Carré: the rule of law. Democracy guarantees the fundamental rights of all citizens through the constitution. But here again, beware of paradoxes: "One could indeed imagine laws passed by a majority of representatives or by a referendum, but which contravene fundamental rights" the philosopher stresses. Democracy cannot therefore be summed up by the majority principle alone.

Finally, democracy is also a way of forming society. It is based on real pluralism: diversity of opinions, beliefs and values. "This presupposes the existence of a relatively autonomous public space in the face of the power in place, which at times challenges the decisions taken by the governments that have been elected,"insists Louis Carré.

In this context, what is the university's responsibility? Louis Carré begins by reminding us of a simple fact: a large proportion of our elected representatives have passed through university benches. But its teaching mission doesn't stop there. "It's about training enlightened citizens, not just rulers. Universities must offer quality higher education, open to as many people as possible", he asserts.

"Democracy does indeed presuppose citizens capable of debating, reflecting, problematizing issues", adds Sephora Boucenna, Dean of the Faculty of Education and Training Sciences and member of UNamur's Institut de Recherches en Didactiques et Éducation (IRDENA). It's all about training reflective minds, capable of questioning their times.

Universities also train those who, tomorrow, will educate future generations: teachers. And here again, democracy is at stake.

In addition to teaching, universities also have a research and social service mission. It produces knowledge that can enlighten public policy, but also question it. This critical function presupposes real independence from politics. "To analyze democratic mechanisms with lucidity, including those that governments put in place, the university must retain its freedom of research and speech," insists Vincent Jacquet.

This critical function of the university presupposes strong independence. In Belgium, however, university funding is largely a matter for the political authorities. "Celane must not mean being placed under tutelage", warns Louis Carré. "Conducting critical research that doesn't satisfy short-term sponsors requires independence, including in terms of resources. We need a large number of researchers who can analyze different types of dynamics. The more we cut research funding, as is the case today, the fewer researchers we'll have and therefore the less capacity for independent analysis and diversity of perspectives, insists Vincent Jacquet.

The "Université en colère" movement, recently launched within the universities of the Wallonia-Brussels Federation, intends to denounce the effects of definancement. Its representatives are calling for "guarantee the conditions for the development of an open, independent, quality university accessible to the greatest number. Faced with the social, economic and political challenges of our time, and because other choices for society, and therefore budgets, are possible, it is more essential than ever to strengthen the institutions and players at the heart of knowledge production."

Democracy is therefore not limited to elections or institutions. It is based on collective vigilance, carried by citizens, knowledge... and the places where this knowledge is built. In this respect, universities are an essential link in the chain of democratic vitality. Provided it remains independent, accessible and open to society.

"Democracy is not just a matter of institutions. It's about citizens who bring it to life and organize themselves to assert their perspectives at different times", insists Vincent Jacquet. A clear invitation not to remain a spectator, but to participate, with lucidity and exigency, in the construction of a common democratic future.