# Radboud Center for Natural Philosophy

Welcome to the website of the RCNP! It is currently still under construction, but feel free to look around anyway.

The RCNP was founded by Klaas Landsman and is dedicated to research at the intersection of mathematical physics, philosophy of science and the history of science. It is embedded within three institutes and centers at Radboud University: the Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), the Institute for Science in Society (ISiS) and the Center for the History of Philosophy of Science (CHPS). Its current focus is on mathematical physics, philosophy of physics and history of physics, and especially on the themes of emergence, randomness and determinism. For a detailed description of the idea behind the foundation of the RCNP and its approach, take a look at this PDF.

The RCNP has its own office in the Erasmus building 18.02. Members work there on Mondays and Tuesdays, and our biweekly reading group is also organised there.

The picture above shows the current members of the RCNP. From left to right: Manus Visser, Henk de Regt, Karla Weingarten, Klaas Landsman, Kian Salimkhani, Silvester Borsboom and Marij van Strien.

## Aim

The RCNP aims to revive Natural Philosophy in the tradition of Newton's *Philosophiae Naturalis Principia Mathematica*, but also in the spirit of modern physicsts like Einstein, Bohr and Penrose, who actively tried to combine natural science and philosophy. We believe that the deepest questions about Nature can only be addressed by an interdisciplinary approach to the mathematical principles of natural philosophy, in which mathematical, philosophical and historical ideas are combined to understand our best theories of modern physics. These domains are often scattered around various faculties, but we explicitly aim to bring them together so that they can reinforce one another.

## Research

Our research currently centers around three themes: emergence, randomness and determinism. We study these themes from the viewpoints of mathematical physics, philosophy of physics and history of physics. In mathematical physics, we work on quantum field theory in curved spacetimes and black hole thermodynamics, trying to understand the emergence of apparently deterministic, thermodynamic laws on the cosmological level from the random behaviour of microscopical constituents in the context of quantum gravity. In the philosophy of physics we work on various topics, centered around fundamentality, emergence and idealisation. Our historical research focuses on determinism and chance in the nineteenth and early twentieth centuries.

## Our logo

The logo of the RCNP is composed of three intertwining Penrose triangles forming Borromean rings.

The impossible Penrose triangle is named after Lionel Penrose and his son Roger Penrose, who is a great inspiration for the RCNP. The triangle was used extensively in the works of the Dutch artist M.C. Escher, who is widely admired among mathematicians. The three triangles stand for the three fields in which the RCNP is active (history of physics, philosophy of physics, mathematical physics), the three main themes of RCNP research (emergence, randomness, determinism), and the three great theories of modern physics (statistical mechanics, quantum theory, general relativity). The three triangles are topologically linked, but cutting one of them will result in two unknotted and unlinked triangles. This symbolises the necessity of combining all three triads in our research.