Sights of Jena
for your information if you and/or your spouse want to go sightseeing
Jena - The City of Light
historical city wall and modern office building
the photograph is taken from a clever perspective, the two buildings are not at all attached to each other.
city skyline
University Main Building
old castle
Three Giants for the History of Optics
Carl Zeiß
Optician and businessman, maker of scientific instruments (wikipedia).
Deutsches Optisches Museum (DOM): currently closed due to construction work.
Image: Ernst Abbe (by Emil Tesch, public domain)
Image: Otto Schott (CC-BY SA 3.0 SCHOTT AG, Andrea Würzburger, Marketing and Communication)
Image: Carl Zeiß (CC-BY SA 2.0 ZEISS Microscopy)
Planetarium History
Weigel's sit-in Globe
In the 1660s, Professor Erhard Weigel built a globe of 3 or 5 metres diametre and placed it on the rooftop of the newly built city castle. The globe called "Pancosmus" displayed the stars with natural light from outside (holes in the globe, seen from inside) and it allowed for a simulation of weather phenomena like rain and hail. It was an "Aristotelian world view".
(image from Kratochwil 2011)
former ZEISS plant, now mall
The dome on the rooftop of the shopping mall called "Goethe Galerie" was originally a test observatory for the scientific instruments developed by the ZEISS company. Since the ZEISS AG moved out of the inner city, the dome has been used for un-astronomical purposes (e.g. as event location and others). At this rooftop, there was the test dome for the projection planetarium ("Ptolemaic world view") in 1922/3.
dancing projector in mall
Jena has so many planetarium projectors that they can set up an old one of them in a shopping mall. The "Cosmorama" projector is the last dumbbell-shaped model before the invention of fiber technology in the 1990s. Every full hour, the model in the Goethe Galerie makes a little "dance" and the German voice of Mr. Spock explains how it works.
Seven Wonders of Jena
Ara
A passage under the altar of the old city church of St. Michael.
Caput
A figure called "Schnapphans" at the town hall that "snaps" on the full hour.
Draco
A seven-headed dragon made from animal bones, wire and paper mache. It was likely made by students in the 17th century, now in the city museum.
Mons
The mountain called Jenzig.
Pons
The Old Camsdorf Bridge in the Old Town.
Vulpecula Turris
The "Fox Tower" is a an old castle keep (German wikipedia).
Weigeliana Domus
The house of the famous 17th century professor of the Jena university, Erhard Weigel. He was one of the great academic teachers of his time (Leibniz studied with him) and invented one of the first pre-planetariums, a sit-in sky globe.