Amsterdam Light Festival

Simon’s first long boat trip, to see all the artwork presented at the Amsterdam Light Festival this year. Pleasantly surprised at how many pieces were inspired with his favorite themes (glass fiber, RGB perception, string theory, neural networks).

This photograph seems to convey the essence the artwork! It’s about string theory, and when you move relative to the piece the strings flicker (vibrate). Try scrolling up and down and you’ll see the same effect!

Science Day in Belgium

Yesterday we attended one of the hundreds of Science Days venues open for free all over Belgium. Simon particularly enjoyed chemistry demos, even though he was disappointed that some companies showing their inventions didn’t want to share the actual formulas behind the tricks.

The simple non-newtonian fluid remains a favourite.

Making your own bath bombs.

Simon dazzled by how insulator foam (polyurethane) is produced as the result of a reaction between two highly viscous substances, an isocyanate and a polyol (polyether). Another fascinating thing about this demo was that the tool mixing the two ingredients actually employed magnets!

A workshop explaining why ships don’t sink and if they do, why:

Exploring 3D printing:

Programmable spheres:

Heat indicator (material changing color depending on water temperature):

The good old baking soda and vinegar demo revisited:


Simon is seriously enjoying his new Molymod chemistry modeling sets and has been obsessing about which set contains what atoms and bonds.

Alcohol (Ethanol):

Hurray! We have just built 7,333333333333 x 10^-9 of the human DNA:


Some like the football, Simon plays with the buckyball, or Buckminsterfullerine, made up of 60 carbon atoms:

Water Fountain Powered by Sound Waves

We built a water fountain powered by sound waves! There is a little speaker attached to the bottom of the water basin. Warning: the sound frequencies in the video may be unpleasant!

And here we tried the same with sand. Again, warning: the frequencies may be unpleasant to your ear, so make sure you lower the volume on your device.

Microstructures Interfering With Light

What looks like strange planets in dark space are actually glimpses of the microstructures forming the Giant Blue Morpho’s wings, as seen through a microscope. Simon told me about how a Blue Morpho’s wings aren’t actually blue (have no blue pigment) but appear blue as a result of a physical phenomenon called structural coloration — microstructures interfering with light. This is almost the same phenomenon as iridescence (making a surface appear to change colours as the observer’s angle of view or the illumination angle changes, think of the soap film in a bubble).

We had found Blue Morpho’s wings in the street about half a year ago. Someone threw a small butterfly collection away — several butterflies pinned to a stick. It looked very cruel and we would have never killed a Blue Morpho for the sake of an experiment, but since we stumbled upon such a rare treasure, we picked up one wing and stored it in a book.

Why Cookies Get Bigger in the Oven


Simon is baking Dutch traditional “pepernootjes” (“pepper nuts” or spicy cookies) and explains why they get bigger in size after you put them in the oven and what the optimal tiling pattern is to fit a maximal number of cookies on the baking sheet.

Physics Experiments: Capillary Bowl

Simon really wanted to try building a capillary bowl – a version of a perpetual motion machine in which water circulates. Although aware of the fact that perpetual motion was not possible, he is keen on seeing it for himself. Off we were to the hardware store where we got some funnels and hoses. What we observed was Pascal’s law in action: the level of water evened out and there was no way to get the water rise higher at one end of the hose than at the other and thus no way to get the water flow into the funnel.

Eventually, we did manage to get the capillary bowl to work for a split second when we filled it with coke and beer. The pressure of water is higher than that of foam, because liquid has a higher density than foam. We used alcohol free beer, so there wasn’t that much foam.