This is the personal site of Tom Roelandts. I’m trying to whet your appetite for science with this thing. My education and interests show through, of course, since I focus on stuff that I feel confident writing about. The site used to be solely about the photos, and I still think the thumbnails page is rather cute, but the emphasis has clearly shifted towards the articles lately.

The Diverging Color Map Is the New Rainbow Color Map

Figure 1. The diverging color map is the new rainbow color map.

I am not a visualization specialist, but I’m convinced that the often used rainbow color map is not well suited for scientific visualization. It might be attractive, but it is not effective. This post mainly introduces diverging color maps as a much better alternative… read more


Submitted on 16 November 2015

The Hubble eXtreme Deep Field

Figure 1. The Hubble eXtreme Deep Field (XDF).

This image is the Hubble eXtreme Deep Field (XDF). It was created by combining many images taken between 2002 and 2012 by the Hubble Space Telescope. The total exposure time was 22.5 days (almost 2 million seconds), and the image contains… read more


Submitted on 8 June 2015

Are there Infinitely Many Twin Primes?

Recently, there has been much progress towards proving the twin prime conjecture, one of the great open questions in number theory. There are infinitely many primes, a fact that was already known by the ancient Greek. A short proof, although not the… read more

Submitted on 25 May 2015

If You See a Fireball, Please Report It

Figure 2. Sightings of a single fireball that appeared on 2015-03-15.

If you have ever seen a fireball, which is an unusually bright meteor (or shooting star), then you know that they can be very impressive. But did you also know that reporting your observation can help to further science? Fireballs, and meteors in general, are like… read more

Submitted on 21 March 2015

Normalized Frequency For The Win

Figure 1. Low-pass filter response with normalized frequency.

Frequency response plots are often shown with normalized frequency on the X-axis. This sometimes confuses people. The normalized frequency is computed by dividing the true frequency by the sample rate. Hence, the sample rate itself has… read more

Submitted on 3 March 2015

Why Clipping Should Be Avoided

Figure 2. Clipped sine.

Before you can digitally process an analog (i.e., real-world) signal, you have to convert it to a digital form by sampling it. A very important aspect of this conversion is that you should avoid clipping the original signal. Clipping happens when… read more

Submitted on 16 February 2015


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