This is the radio anechoic chamber at Denmark’s Technical University (DTU). It opened in 1967, and is currently operated with the European Space Agency (ESA) for the testing of microwave antennas for use in satellites and mobile networks, among other things that I am not even going to try to explain. The idea is to minimise any reflections of microwaves, and the big foam spikes are filled with carbon and iron to absorb the radio waves. This tests the effectiveness of the antennas without any external intrusion, simulating the conditions of, for example, space. Many of these chambers are blue in colour, and according to Sergey Pivnenko, the professor in charge of the chamber, most of them were black in the old days – then some bright spark noticed that it was a bit depressing to work in a black spiky room all day, so the manufacturers of the spikes started to produce them in blue.