ľ�ϸ���Ӱ��

Gauvain Leconte-Chevillard [Namur ľ�ϸ���Ӱ��]

The seventeenth century is often taken as a turning point in the study of religious texts by Western European Christian scholars: as a period that witnessed a shift from “sacred philology” guided by faith to “critical scholarship” built on the principles of reason. In parallel, the period saw a significant increase in the Christian knowledge of Hebrew and Jewish literature, as well as a push to exclude esotericism from academic theology in favour of a “rational” faith. My paper will engage with these narratives by focussing on the case of Christian scholars studying the Zohar, a key text in the Jewish esoteric tradition known as the Kabbalah. I will argue that by exploring the intersection of Zoharic study with Christian biblical scholarship, we can discover something unexpected, not just about the nature of philology as a critical enterprise, but also about how Christian orthodoxies constructed the image of Judaism.

Itamar Ben Ami will comment upon Marcello's contribution.

Scalar fields & spacetime-matter dichotomy

The combination of Mach’s hypothesis concerning the material origin of inertia in mass-interactions and Einstein’s equivalence hypothesis on the unity of inertia and gravity raises the intriguing possibility that gravity may be explained entirely as the dynamical part of a relativized law of inertia. This idea—which was not fully realised in general relativity—was first clearly articulated by a colleague of Einstein, Hans Reissner, so I have named it “Reissner’s hypothesis”.

In this talk, I will revisit this overlooked idea and motivate its reconsideration by clarifying the philosophical appeal of Mach’s principle and Mach’s hypothesis. Drawing primarily on Dennis Sciama’s doctoral work, I will show how Reissner’s insight can be captured in an elegant equation linking the strength of gravitational coupling to the cosmic mass distribution. In the final part of my talk I discuss how similar expressions were considered by leading physicists such as Robert Dicke, John Wheeler and Pascal Jordan throughout the 20th Century for a variety of reasons not always related to Mach’s principle, I then explore some of the possible cosmological implications of these ideas.

Rami Jreige

Humans are social beings. However, we are not alone in the realm of social reality; we share this space with diverse entities, even more than just other animal organisms.  In my work, I develop a new empirically-informed framework for studying social systems that broadens the concept of social reality. This framework is based on three building blocks of social systems: i.) interactions, ii.) relationships, and iii.) social units; and it redefines the manner in which various interactive systems are studied and perceived, encompassing diverse living entities at different levels of organization — from the intricate interplay between hosts and their microbiomes to the interactions among human beings and social groups.

In this presentation, I will present this framework and how it can contribute to recent discussions about the adequacy of using race and/or ethnicity as scientific proxies in microbiome research. I propose that applying a social systems perspective to holobionts (hosts + microbiota), and their interactions challenges the use of race categories in microbiome studies. This perspective views human-microorganism associations as dynamic, evolving social networks which develop over time within complex and fluctuating contexts, rather than fixed traits, offering a more nuanced understanding of human diversity. Additionally, this approach can help us to rethink current models of planetary health and zoonotic diseases to properly acknowledge multispecies social relationships. This presentation is programmatic and outlines the work I will develop during my junior fellowship at the Descartes Centre over the next three months. The research is open to feedback and aims to foster collaborative engagement as it develops.

The indirectnesses of dark matter detection

[Tufts ľ�ϸ���Ӱ��]

How can we write the history of science? In the past few decades, historians working in a variety of fields have challenged the obsolete—but enduring!—narrative of scientific progress that dominated much scholarship on the history of science in the twentieth century. Instead, scholars have focused on scholarly practices, approached science as historically and culturally contingent, identified the “stuff” of science, and looked beyond household names to ask new questions about how scientific knowledge is made, how it circulates, and which other types of knowledge are suppressed in the process.

In this session, historians of science Eric Jorink and Richard Calis discuss their recent books to think further about how we can write the history of science today. They will introduce their work, respond to one another, and explore topics such as the recent shift from scientists’ ideas to their working practices, the potential of archival research for the history of science, and how processes of canonization change our understanding of ‘normal science at work’.

Black Holes as Massive Spacetime

This talk aims to introduce the microscopic state counting of the extremal black hole, performed by Andrew Strominger and Cumrun Vafa, and to analyse the argument’s conceptual structure. In particular, I will identify the various inter-theoretic relations on which it depends. I will also discuss further conceptual questions that the calculation invites: Is the black hole in some sense the same physical system as the D-brane system? Is the black hole in some sense emergent from the D-brane system?

Dominic Ryder [LSE]

Evidence in cosmology: how galaxies became complicated

In contemporary philosophy of science, it is widely accepted that what counts as evidence for a theory depends on the theory itself (e.g., Kuhn 1962; Laudan 1978; Kelly 2016). What scientists observe, measure, and interpret is shaped by the theoretical frameworks, instruments, and practices within which they work. Much philosophical work has been devoted to the problems arising from this theory-ladenness (Boyd and Bogen 2025). However, the question of how exactly a theory selects its evidential base, i.e., how a theory determines which data are evidentially relevant in the first place, remains largely underexplored.

Simon Allzén [Stockholm ľ�ϸ���Ӱ��]

A quasi-local, functional analytic method to detect the stationary limit surfaces of black hole spacetimes with stationary regions is presented. The method is based on ellipticity-hyperbolicity transitions of the fundamental fermionic and bosonic Hamiltonians occurring precisely at the locations of stationary limit surfaces. These transitions can be analyzed by means of the determinantial polynomials of the principal symbols of the Hamiltonians, which in numerical algorithms is computationally favorable over the usual differential geometric procedures that employ either scalar polynomial curvature invariants or Cartan invariants. Moreover, since the functional analytic method relies solely on the effects that stationary limit surfaces have on the time evolutions of the fundamental fermionic and bosonic fields, it is in a sense ontologically different from the differential geometric procedures, which are purely based on the local geometries of the underlying black hole spacetimes. As an application, the detection method is used to determine the locations of the stationary limit surfaces of the Kerr-Newman black hole spacetime. Furthermore, it is shown that the functional analytic method serves as a quasi-local event horizon detector for black hole spacetimes with static regions and gives rise to a relational concept of black hole entropy.

Descartes Centre Summer Colloquium: Inspiring Stories and Positive Motivations in Science

On Tuesday 17 June we are hoping to organize a colloquium that features a series of inspiring moments, historical or current, personal or not, that will raise all of our spirits and remind us to continue all the good work we are doing despite the difficulties we face.

We have reached that time of the year where we are all yearning for our summer vacations! But before we say goodbye for the summer, we get the lovely opportunity to gather once more for the Summer Colloquium. This year we have all been overstimulated with news from around the world. We have heard about political attacks on science, research censorship and an overall decrease in funding. All of this is rather disheartening. But we still love to do what we do.

That is why during this rendition of the Summer Colloquium we want to focus on the positive, on our motivations, on our key vales. This year we will be hearing Inspiring Stories and Positive Motivations in Science. We want to hear about all that makes you keep going, from positive moments with colleagues, to personal values and general inspirations. Anything that keeps you motivated to continue. Let’s keep going, and let us support, inspire and motivate each other in keeping us going.

This year’s Summer Colloquium will be all about the things that inspire us and motivate us to do science, in five to ten minute presentations featuring stories, images, books, films, letters. Anything that gives you the drive and enjoyment that comes with doing science. Our aim is to inspire each other by showcasing the strength and resilience that stems from the positive values and motivations that encourage us.

Join us for the last Descartes Centre Colloquium of the academic year. Afterwards, there will be drinks! 

Influential Patient Stories: Gynaecologists and their patients in the Utrecht Academic Hospital in the 1920s

Historians have argued that the rise of modern hospital medicine since the end of the eighteenth century led to the disappearance of the patient’s narrative. Patients’ stories about illness and health were largely replaced by physical diagnoses when physicians started focusing on observable physical symptoms instead of patients' emotions and experiences. Yet, even in the context of medical specialization in 20^th-century hospitals, patients' stories remained indispensable for doctors in making diagnoses. This paper examines the influence of the patient’s voice on doctors in the gynaecological department of the Academic Hospital in Utrecht in the 1920s.

Another Critical Look at Inflationary Cosmology

Emergent Gravity (EG) is a framework in theoretical physics according to which “gravity is not a fundamental interaction” and “spacetime is a composite object approximately like a fluid” (Liberati 2017). Literature on recent attempts at providing robust models in emergent gravity are replete of moves labelled as “plausible” by scientists themselves. After reviewing important contributions in this framework, I show the sense in which plausibility is used in emergent gravity and discuss the limits encountered by this approach when it relies on analogical reasoning. In particular, I will discuss the use of acoustic black holes in EG and highlight the generation of what I call the “double-gap problem”, resulting in the difficulty of filling a gap between theory and experiment or models and simulations, as well as in an ontic jump from mathematics to physics.  By no means this alter the significance that EG has within the landscape of theoretical physics, I rather try to provide a toolkit to avoid certain inconsistences and stimulate the debate about the epistemological questions raised by EG approaches.

Video

 (even shorter version )

Eugenio Bianchi & Carlo Rovelli [ľ�ϸ���Ӱ�� of Marseille]

Revamped Science Communication: A Tour of the Renewed ľ�ϸ���Ӱ�� Museum Utrecht

We will take a tour of the “museum for curious people” guided by the people who have made it possible.

We will explore the room Kijk, wij dieren (lit: ‘look at us animals’, where it is possible to observe objects of interest for natural history and Blaschka glass models). Paul Lambers, curator of the natural history and scientific instrument collections, will be the guide.

Lastly, we will visit and explore the room Uitdokteren (lit: ‘figuring it out, physician style’, home of the medicine collection). Reina de Raat, curator of the medical and dental collections, will be the guide.

Not the Measurement Problem’s Problem: Black Hole Information Loss with Schrödinger’s Cat

 [Tufts ľ�ϸ���Ӱ��]

Florentine Medical Alchemy in the Renaissance and a practical hands-on experience in the ArtLab

Talk 1 (Jo Hedesan): Francesco I de Medici’s Alchemical Laboratory as Depicted by Jan Stradanus (1570)
My talk will revolve around a painting of an alchemical laboratory created by Jan van der Straet or Stradanus (1523-1605), a Flemish-born artist settled in Florence. In 1570, Stradanus, who was at the time part of the workshop of the better-known Giorgio Vasari, was commissioned for two paintings meant to adorn the Studiolo of Francesco I de’ Medici (1541-1587). The best one is known as The Alchemist’s Laboratory, and was a depiction of the distillation works in Palazzo Vecchio.

I will be discussing what this image and connected information might tell us about the Palazzo Vecchio laboratory and princely alchemy at the Medici court. The laboratory was set up by Cosimo I (1519-1574), the first Grand Duke of Tuscany. His son Francesco was also enthusiastic about laboratory practices: Stradanus’s painting portrays the prince working on the premises amongst other artisans. It seems that the primary purpose of the laboratory was focused toward making medicines. My talk will present the depiction of the laboratory, instruments and practices by linking them with what we know about 16^th century medical alchemy. I will also discuss the complexity of ‘reconstructing’ the Palazzo Vecchio laboratory in light of Stradanus’s depiction, which draws on other contemporary representations and is meant to convey an underlying ideology.

The laboratory of the Palazzo Vecchio seems to have been closed soon after Stradanus’s painting was finished. Francesco commissioned a new Medicean palace, and once the Casino di San Marco was finished in 1575, he relocated the majority of the alchemical works there, hence creating one of the first purpose-built scientific institutions in the world.

Talk 2 (Stefano Mulas): Don Antonio de’ Medici’s Casino di San Marco and its Book (La fonderia, 1604).
In this speech, I would like to present some of the testimonies of the alchemical interests carried out in the Casino of San Marco during the time of Don Antonio, i.e. the book of La fonderia. This work provides practical information, describing a collection of recipes according to the three principles of the Paracelsian philosophy, such as salts from herbs and plants. Moreover, through the reproduction of some of these remedies, we will delve deeper into this practical literature to understand some of the instruments, methods, and results of alchemical practice in 17th century Florence.

Hands-on workshop (Jo Hedesan, Stefano Mulas and Thijs Hagendijk)
In this workshop, we aim to rework an early 17^th-century demonstration of Paracelsus’ tria prima. In his chymical textbook, Tyrocinium chymicum (1610), The French iatrochemist Jean Beguin (1550-1620) described various ways to experientially illustrate the Paracelsian approach to medicine, which described the composition of medicines (or matter, more generally) in terms of three principles: mercury, sulfur and salt. During this workshop, the participants will try to recover these principles from organic material.

Circularities in the search for empirical grounding for the cosmological principle

Video

Academia and Activism

(Preliminary) Program
13:00-14:00       Workshop for students

14:00-14:30       Break/welcome with coffee and tea

14:30-16:00       Workshop with short presentations (among others: Erik van Sebille, Paul Boselie, Mattias Janson, Paul Ziche, ...)

16:00-16:15       Break

16:15-17:00       Lecture by Thomas Fossen (Leiden ľ�ϸ���Ӱ��)

17:00-17:30       General discussion

17:30-18:30       Drinks

In order to be able to plan in detail, please register for this afternoon, indicating which part(s) of the program you want to participate in! Registration is possible by replying to this email or by sending an email to a.dendaas@uu.nl. You will receive a confirmation and some instructions on how to get to the theater.

A brief description of what we aim at with this day:

„Academia and activism“.

The urgency and the inter-/transdisciplinary appeal of this topic need not be argued for – the term “Academia” is adopted here to not only cover the different types of academic disciplines, from the humanities and the social sciences to the natural sciences and medicine, but to also include the academic institutions qua institutions. What we are interest in during this day – in accordance with the Descartes Centre’s mission – , are questions at the interplay between broader conceptual questions and concrete practices, and in how this relates to questions concerning the role of science and of scientific institutions.

We want to organize this day together with institutions and colleagues throughout the university (and, this being a first and therefore also somewhat experimental event, we start on a moderate scale, with the intention to explore this format, and to take this as a first step towards larger events); this topic also comes forth from discussions within the UU’s “Open Science”-movement.

Here are some of the more specific questions that we may discuss – these are intended as suggestions and examples; we want to invite your ideas for topics that we can discuss during this event:

-          Is academia inherently activist, by virtue of its critical spirit? Or should academia, or should ‘science’ (in the broad sense of the term) be neutral and thus refrain from activism? (So we may also question the “and” in the title – should that rather be an “and/or”?)

-          Is science-based activism different from other forms of activism?

-          Is activism a challenge to ideals such as the free exchange of ideas within the scientific community?

-          Can an institution, qua institution, be activist, or is this an attitude or form of activity that needs to come from individuals?

-          Is activism a form of public engagement? Very concretely: should we include activist activities in the UU’s rewards-and-recognitions schemes? How does activism relate to the societal responsibility of the scientist?

-          How activist should the UU be in its communication strategies? How does science-based activism make us of specific media?

-          What is the role of symbols in activist activities – the gown, the lab-coat? What are the symbolically relevant venues for science-base activism?

-          Whom is an academic representing when they participate in activist activities, wearing the professorial gown or a lab-coat? Themselves? The university? ‘Academia’? ‘Science’? This question clearly has legal implications as well as conceptual ones.

-          What should be the role of activism in teaching at universities? Should we train students to become activists?

-          How do colleagues in academic administration, communication and other support roles come into contact with issues relating to activism?

-          A very generic question: All of these problems come together in a asking: What are the boundaries of ‚activism‘? What is the room to maneuver? And how do we keep an open dialogue  on setting new boundaries?

Video

William J. Wolf [ľ�ϸ���Ӱ�� of Oxford] and Patrick M. Duerr [ľ�ϸ���Ӱ�� of Tübingen]

Descartes Centre Summer Colloquium