Johan Hidding's homepage
About
This is the personal homepage of Johan Hidding. I'm a PHD student astronomy at the Kapteyn institute at the University of Groningen. My research interests are: cosmic structure formation, the cosmic web, (computational) geometry. In particular I study the Zel'dovich and Adhesion approximations to the formation of the Cosmic Web. My main collaborators are: Rien van de Weijgaert (promotor), Sergei Shandarin, Gert Vegter, and Bernard J.T. Jones. On this page you can find several things either having to do with astronomy or not.
Astronomy
- A poster on structures in the Local Universe, featuring the Perseus-Pisces supercluster! If you like it, here is a high resolution version (33MB).
- Hidding, Shandarin & van de Weygaert - The Zeldovich Approximation: key to understanding Cosmic Web complexity - DOI:10.1093/mnras/stt2142
- My talk "the Phase-space Geometry of the Cosmic Web" on the QU3 symposium. There is almost no text in the slides of this talk, this is compensated in the above paper.
- Adhesion poster, a poster on the Adhesion approximation as presented on the 4th KIAS workshop on cosmology.
- Large scale structure, my masters thesis blog.
- On the amount of dark matter in the Universe, a website I made during my bachelors for Actueel Onderzoek.
- Waar zijn ze dan? (in dutch) on the Fermi paradox
Adhesion model & Computational geometry
In this movie I show how the adhesion model can be computed using a weighted Voronoi tessellation.
Zeldovich Approximation in Blender
The equations describing the Zeldovich approximation are identical to this system in geometric optics. The slab of glass has some minute deformations, which are made visible with a collumnated beam of light and a projection screen. As the slab moves upward, the deformations grow and caustics are formed. This movie was made with Blender and LuxRender.
Music
I've been playing the piano for some time. A few years ago I discovered singing was much more fun. I'm currently singing tenor in the Bragi a-capella choir, vocal ensemble Cantatrix as well as more irregular projects that cross my path.
- Dutch national student choir (NSK)
- NSK Programma 2010: wat google ons vertelt
- Bragi - *the* student choir of Groningen directed by Rein de Vries.
- Cantatrix - an ambitious choir operating in the northern part of the Netherlands with Geert-Jan van Beijeren Bergen en Henegouwen.
- Slotkoor - one week of ultimate musicians heaven at Sloß Seehaus under the leadership of Fokko Oldenhuis, featuring sunny Bavaria, a private chappel (with organ), plenty grand pianos, delicious foods from our own chefs, eternal happyness, and German beers and wine.
Programming
Allthough I do most of my programming in C++ and Python, I've a dilletante curiosity in more aestheticly pleasing languages like Scheme. At the moment I'm also learning the ins and outs of D, supposed to be C++'s successor. If you have ever done serious C++ coding the way its meant (using STL containers, iterators, standard algorithms and templates) you will know the kind of frustrations that drove people to design D. Recently a majority of C++0x features are supported by the latest GCC compilers, giving some of the power of scheme to C++.
There are some things that I made that could be considered remotely usefull. These are gathered somewhere else.
Links
Music
Programming- Frank Brokkens C++ annotations
- Abelson and Sussman video lectures on programming. This is not just a course in programming LISP, but teaches a lot of wisdom in programming in general.
- Structure and interpretation of computer programs
- A good reference for R6RS scheme.
- Python Everything you need to start programming Python is here. The language, tutorials and documentation. Python is the easiest, most powerfull and most readable language I have ever used. This has two good reasons: it has a huge standard library (batteries included) and indentation is a syntax element which forces you to write readable code.
- A book on classical dynamics.
- Dimensions - a series of beautifully rendered movies on four dimensional geometry, fractals and topology.
- LinuxCommand.org Teaches about the GNU/Linux command line.
- Paul Bourke's pages
- Paul Graham's pages