Free Walking Sightseeing Tour #4 in Potsdam, Germany

The historical Royal Prussian War School and the Schwechten building is a building complex that was built on the Potsdam Brauhausberg from 1899 to 1902 on the instructions of Kaiser Wilhelm II. The building ensemble was continuously used after the dissolution of the war school in 1919; From 1946 to 1952 and from 1990 to 2013 it housed the Brandenburg state parliament until it was replaced by the Potsdam city palace. From December 2015 to September 2018 it was a refugee accommodation. From the second half of 2019, 200 apartments will be built in the building. In the GDR period, the nickname "Kremlin" prevailed for the complex.

Wikipedia: Kriegsschule (Potsdam) (DE), Heritage Website

The Brauhausberg is an elevation 88 m above sea level in the Teltow suburb of Potsdam, Germany. It is located in front of the Ravensberg Mountains and forms the northern end of the Saarmund terminal moraine arc. Its name derives from a brewery opened on it in the early 18th century. Its southern neighbour is the Telegrafenberg, which was called Hinterer Brauhausberg until 1832. The Brauhausberg is considered an ancient natural landmark in the glacial valley, long before the Havel existed.

Wikipedia: Brauhausberg (DE)

The Helmertturm is an astronomical-geodetic observation tower on the Telegrafenberg in Potsdam, Germany. It is a listed building.

Wikipedia: Helmertturm (DE), Website, Heritage Website

Potsdam Great Refractor is an historic astronomical telescope in an observatory in Potsdam, Germany.

Wikipedia: Potsdam Great Refractor (EN), Website, Heritage Website

The Michelson interferometer is a common configuration for optical interferometry and was invented by the 19/20th-century American physicist Albert Abraham Michelson. Using a beam splitter, a light source is split into two arms. Each of those light beams is reflected back toward the beamsplitter which then combines their amplitudes using the superposition principle. The resulting interference pattern that is not directed back toward the source is typically directed to some type of photoelectric detector or camera. For different applications of the interferometer, the two light paths can be with different lengths or incorporate optical elements or even materials under test.

Wikipedia: Michelson interferometer (EN)

The Einstein Tower is an astrophysical observatory in the Albert Einstein Science Park in Potsdam, Germany built by architect Erich Mendelsohn. It was built on the summit of the Potsdam Telegraphenberg to house a solar telescope designed by the astronomer Erwin Finlay-Freundlich. The telescope supports experiments and observations to validate Albert Einstein's relativity theory. The building was first conceived around 1917, built from 1919 to 1921 after a fund-raising drive, and became operational in 1924. Although Einstein never worked there, he supported the construction and operation of the telescope. It is still a working solar observatory today as part of the Leibniz Institute for Astrophysics Potsdam. Light from the telescope is directed down through the shaft to the basement where the instruments and laboratory are located. There were more than half a dozen telescopes in the laboratory.

Wikipedia: Telegrafenberg (EN)