Besides celebrating my birthday last Saturday I also visited saw windmill De Ster in Utrecht together with my brother and his wife and children. It was a so called Monumentendag (European Heritage Day), which means that a lot of monuments are open to the public. De Ster is the only original saw windmill in The [...]
8Sep08
Sulfur Hexafluoride
Most people know helium as a gas which is used in filling balloons and as a gas which can alter your voice, it raises the tone of your voice. This is because helium is light weight. But there is also a heavy gas called sulfur hexafluoride which does the opposite: it lowers the tone of [...]