You know you are working in the right place when you find yourself proudly wandering around your workplace with a full bag of original 80s LEGO blocks. People cannot help but throwing inquisitive looks and you go like "It's SCIENCE.".
Today I had to take some measurements with my colleagues Aki and Alexander in the Physics Department X-ray tomography laboratory. This was a completely new experience for me, having myself the background of a theoretical mathematician. Nonetheless, it was exciting to learn how the collecting data machinery works. LEGO blocks were used in the spirit of what Aki prophetically taught me regarding experimental physics: "Whatever works!". We needed to move the sample during the measurements and we used the blocks to control the shift distance and stability better. Some previous LEGO playing was required in the sake of experimental science.
A couple of words must be spent regarding the sample. We used the classical "Helsinki walnut"(*). It was a little awkward when I went to the shop to buy only two walnuts. I tried to brag with the cashier "I am gonna X-ray them." but I had the feeling this did not impress her very much. Weird.
The walnut was a brilliant choice of real data for sparse X-ray tomography. It has a good variety of attenuation areas, non-trivial boundaries, and totally looks like a brain. It is an excellent alternative to the classical Shepp-Logan phantom. The walnut dataset is about to become public for the benefit of other researchers (I promise I will spread the news on my blog as soon as it gets published).
Now let's keep fingers crossed that I guessed well the customer's needs with such measurement.
(*) See the paper about sparse tomography by Hämäläinen et al..