Well, it is not just decoration, the planetarium is still operating, the Earth takes 365.25 days for completing one circle around the sun, and the other planets rotate also according to their orbital period

Visited the planetarium in Franeker, certainly a must See place

Visited the Deutsches Schallplattenmuseum in Nortorf, low expectations which were greatly exceeded, this ist a great place with respect to history of technology and culture...

This is certainly going to BE an amazing conference ...