Dirk Bertels

The greatest malfunction of spirit
is to believe things (Louis Pasteur)



This personal site covers a wide variety of topics including science, mathematics, computing and music. Use the tree navigation on the right to browse through them.

Many articles are continually reviewed and updated. In particular life sciences - a compilation and physics - a compilation which archives and discusses interesting scientific concepts, and homespun philosophy - covering topics and ideas based on the humanistic sciences. There is also my blog which is rather infrequently used since most of my entries end up on other relevant pages.

Following listings cover the most recent additions - latest ones listed at the top.

Spiral-bound book: Exploring music with the 5 string banjo

This book aims to bring something new to the already profuse material on the 5 string banjo. It stands apart from these other books in that it is aimed at the serious musician, whatever his or her level may be. More than 150 A4 pages of text, tables, diagrams, tabs and music notation. Available in digital and hardcopy formats.

You can Look inside this book on Amazon. You have the choice to order a hardcopy or digital copy directly from the author here, or order a hardcopy through Amazon.

EP Recording: Banjo Demo 2015

Demo EP recorded in August 2015. The background music is entirely self-composed. The EP is a selection of 4 tunes from a solo performance repertoire spanning a variety of styles including African, old-time, bluegrass, salsa and balads.

New android app for twitter users: TweetNEST

This is the frontpage for an android app I coded this year.

It has been uploaded to the android app market - but still needs extensive marketing to get people to buy it.

TweetNEST is a tweet archiving and management tool for twitter users who want to be able to download and store tweets from selected twitter users so they can be managed in a local archive.

Banjo Project The Joy of Life

Videos of some tunes from my 5 string banjo repertoire - recorded late 2013. Many originals, some covers plus some jigs, slip jigs, reels and bluegrass standards.

Scores of these tunes are also available for download - includes music notation, 5 string banjo tablature and chord charts.

Compiled excerpts on J.S.Bach

Every 5 years or so, I tend to throw myself into the monumental crevices that constitute Bach's music - every time disvovering new things and appreciating its art more deeply. I have been accumulating many excerpts from books and articles on Bach since the early 1990's. This compilation consists of a chosen selection from this material.

Higgs Force, the 5th universal force

Very readable article on the discovery of the Higgs Boson, based on lectures given by physicists involved in the experiments that led to the discovery at Cern.

Managed C++ Intel Hex files and Conversions

Code for C++/CLI to read Intel Hex files, store data only to a buffer and the various conversions necessary to do the deed.

Alfons Stout - Antwerp Organist and Composer

A compilation of previous writings and readers' contributions to a distant family member of mine for whom I had great admiration.

Some thoughts on Musical Practice and Performance

Started off this new page which is by no means complete but should give me something to work with. During practice all kinds of ideas spring up and this is the place I can indulgently elaborate on them. Most writing is on practice, not so much on performance as yet ...

More pages on the 5 string banjo

These pages are in addition to The Five String Banjo page I created previously. I am also working on a Banjo Tab manual that lists tunes and licks + performance notes. It will be in CHM Help format to facilitate navigation between topics.

Calculating String Tension

Derives Tension equations, both using imperial and metric units, from a standard equation. Useful for situations where you need to know which string gauges to use without overloading your instrument.

Threads in managed C++

Code frameworks for using the Thread class and the BackGroundWorker, which gives you the option to take action on your thread's progress, useful for progressbars etc.

Fretboard scaling

Uses data obtained from the previously written pages Constructing Scales and Scales and Tuning to construct some equations for calculating fretboard spacing. I used these to compare some fretboard scales for the banjo on the The Five String Banjo page. Also includes a link to a spreadsheet.

The Five String Banjo

Having played the 5 String since my teenage years off and on, I have accumulated a lot of musical material. This page so far covers more general topics on the banjo such as its African heritage, influences, tuning, string gauges, notation, software, fretboard scales, and links. So the stage is now set to include some music ...

Digital Imaging Resolution

A new category has arisen - Imaging. Its new page, Digital Imaging Resolution provides a platform to jot down some theory and throw some light on the various, often confusing, concepts and terminology regarding digital imaging resolution. Thus far it covers Charge Coupled Devices, Optical Format, Physical Pixel Size and Spatial Resolution. More recently added info about High Resolution Colour Imaging and its application to Medical Imaging.

So many knots, so little time ...

A page that lists my favourite knots - with some explanations and further links

Deploying a Visual studio application with NSIS

Another addition to the Managed C++ section. Describing how to use the Free NSIS software to deploy a Visual Studio VC 2008 application including taking care of the additional libraries that your app will need, checking for previously installed versions and serial number registration. Also describes how to debug a Side-by-Side configuration is incorrect error using sxstrace and Depends.exe.

Short Histories

A compilation of (to my mind) interesting historical events. Currently contains following topics: The Ascent of Money, Classic Languages, The Black Man's Burden, History of science, History and Science of Cannabis.

Links, Sites and Software

Something I've been wanting to do for some time now - archiving interesting links, websites and software products. This page is intended to be regularly updated.

Managed C++ Programming

Some new pages on managed C++. The code excerpts are a small compilation of managed C++ code I found especially useful during my last 5 years of programming using this language. I also dedicated a full page on a printing mechanism to print a DataGridView table whose columns are filled from an Access database (mdb) file. It is based on another article in C#. The last link is a step by step explanation on how to connect a PostgreSQL server-side database to a Visual Studio application.

C Code Topics

A work in progress. Discusses some topics on the C language. Writing about this helps to string things together in my own mind. It's a bit of a mix containing some insights on basic stuff and interesting code.

The Atom: Filling the Gaps

Explores how to calculate the electron configuration of elements using the periodic table instead of using these confusing tables.

Quotations and Statistics

New page that has some interesting statistics, general quotations and quirky quotations.

Piano Groove Tutor Version 0.7

Latest version that incorporates tempo and volume locking, and allows people to create their own sessions.

Piano Groove Tutor Version 0.5

A stand-alone version that replaces the earlier Java Web Start version. New features include expandability, adjustable loop settings, and volume control.

New commenting system

Another web programming project that uses Ajax. This one covers a commenting system I built for the web site. This system is easy to integrate in to any web page using Javascript (Ajax), PHP, and MySql. It is asynchronous, meaning it communicates with the server behind the scenes, has local form validation, security code entry in the form, and sends notification emails. Try it out at the end of the article.

Video Editing using Free Software

Finally managed to put this writing I started more than a year ago onto this site. It discusses editing video, such as video captured from a camcorder or webcam. It has a special section on editing DVDs and burning it back to DVD (a feature which is in great demand) - all this using free software. For the editing part, I use Avisynth which requires some scripting skills.

Using Ajax with PHP

Ajax is a great addition to the web developing world - mainly because of the new possibilities it brings in web design. Ajax, which is a Javascript subset that handles data transfer between client and server asynchronously, is truly the mother of the new generation of web standards, generally referred to as Web 2. This article illustrates some of my favourite Ajax applications, both with code and examples you can try out on the page itself. Even if you're not code-literate, try out the examples to get a feel of what it can do.

Piano Groove Tutor

My combined interests in music and programming have resulted in this simple but effective java application. This article covers the general workings of the program as well as some implementation issues. These issues are not only relevant to the Java Midi engine but also discusses more general topics such as interacting with GUIs created with Java's Matisse engine and substituting Java's lack of support for dynamic variables with HashMaps.
All in all, the program's use of midi files and well-formatted music scores are all one needs to create a very good practicing environment.
Update: A second page, piano tutor demo, has been added to assist you in trying out this program using Java Web Start. It also has a forum for you to leave your comments.

Google Tricks

Google has achieved what few conpanies have - become a verb. While most of us google to find information on the net, not many are aware of the powerful capabilities we have at our disposal. The examples in this article illustrate how you can use the Google searchbar in more creative ways ...

Videos of Bach performances

Videos and commentaries on 12 of my favourite Bach pieces - all recorded on digital piano. The process of recording these, finding the software to edit them, doing the editing and finally posting them on to YouTube (from where they can be linked to this website), was quite laborious. Links to relevant sections of my page, Bach Workbooks, are given where appropriate. Some commentaries on how I did the deed can be found on the calendar notes page.

Concepts in Science

Quotations from various scientific literature, intermingled with some notes of my own, or from sources I have long forgotten. The notes were accumulated over a period of time and classified according to topic.

Philosophy of science

Philosophical quotations taken from literature on science.


Some thoughts on PI. Contains a conceptual diagram and code to calculate PI

update: Pentagon

Added a section on the Pentagon Knot and some ramblings about soap bubbles.

Calendar notes

A kind of web diary for me to jot down thoughts, ideas, or notes which don't have a place in any of the categories. This should give my website a more personal touch (for better or worse).

Piano Diary 2000

Includes musical examples and lists some of my favourite piano blues, salsa, and funk licks. I have more diaries in the pipeline (they all need converting for the web). My more recent favourite music involves Jazz, African music and Bach.


Updated extensively to include a hypothesis of mine which states a unique relationship between PHI and the base of our number system, 10.

So far, I haven't come accros any documents that addresses this issue. So if you're intrigued by the nature of PHI, the Fibonacci series, the Pentagon and all that, this is a good place to look.

Penrose tiles

How to make amazing patterns using just 2 types of triangles inherent in the pentagon. Includes examples and necessary measurements to make these triangles.

Internet Explorer Privacy

How to get rid of secret files that stores information regarding ALL the web pages you visit, thereby compromising your privacy.