When I realised that the coach was going past Magdeburg on the way to Berlin I got very excited. I tried to photograph the sign on the Autobahn but we were moving too quickly! So you get a picture of the outskirts of the town. It was at Magdeburg that they did a famous experiment about vacuums. They got two huge hollow steel hemispheres and put them together. The join was sealed with something airproof like Vaseline. There was water inside which was boiled. The steam was allowed out of a small hole and pushed the air out with it. The hole was sealed and the apparatus allowed to cool. The steam inside condensed to water leaving a pretty good vacuum inside. Two teams of horses couldn't pull the hemispheres apart because the high air pressure on the outside pushing in met no counter force from the vacuum. At least this is how it was told to me by my Physics teacher. Perhaps I should check that I've got all of the details correct...
