Stellingen (Propositions)


It is a nice tradition at Dutch universities to provide a sheet with Stellingen together with the manuscript of the Ph.D. Thesis. Originally, I have been told, the Stellingen indeed were the actual thesis to defend, and what we call a thesis nowadays developed from the growing size of footnotes to the Stellingen.

Browsing the web, you will find that typical Stellingen contain about 10 or so statements, often with an increasing nonsense gradient. Nevertheless, the candidate can be questioned (and has to answer) about each point in the Stellingen during the defense.

Below you will find my 10 Stellingen, which I was ready to defend on January 17th, 2008 in the Agnietenkapel of the University of Amsterdam.

Stellingen for my thesis Simulation of Complex Flows and Multi-Physics
with the Lattice-Boltzmann Method

  1. The Navier-Stokes equation is not able to describe all possible kinds of flow, but the Lattice-Boltzmann method is in principle suitable to simulate all kinds of fluid flow which can be described by the Navier-Stokes equation.
  2. Different micro-worlds can produce the same macroscopic behaviour. The conserved quantities of the macro-world are related to the symmetries of the micro-world.
  3. There is no best method in CFD, but always one which is best suitable to solve a given problem.
  4. The Lattice-Boltzmann equation can be properly applied without knowing about the Boltzmann equation, although a good understanding of the Kinetic Theory does not always result in its proper application.
  5. No paper should be accepted for publication, which is stating the Lattice-Boltzmann method is `easy to implement and parallelisation is simple and straightforward’.
  6. It is no contribution to science when the information hidden in nature gets lost in the terabytes of data produced by numerical simulation.
  7. It is easier to implement inefficient code with modern object-oriented languages, but it is not always a good idea to compensate a lack of thinking power by computing power.
  8. When scientists get less productive with the years, this is not due to a biological aging process, but due to increasingly unproductive living- and working conditions.
  9. Doing research in Medical Physics does not automatically improve ones own health.
  10. It is not true that all Stellingen contain negative remarks about the Netherlands, although it is true that most German believe that most Dutch can’t drive.