Editing Planetarium (section)

=== 20th century ===
[[File:25 jarig bestaan van het Zeiss Planetarium Haagse Crt Dr J J Raimond jr, Bestanddeelnr 910-1522.jpg|thumb|The world's first planetarium projector, Zeiss Mark I, 1923]]

In 1905 [[Oskar von Miller]] (1855–1934) of the ''[[Deutsches Museum]]'' in [[Munich, Germany|Munich]] commissioned updated versions of a geared orrery and planetarium from M Sendtner, and later worked with Franz Meyer, chief engineer at the Carl [[Carl Zeiss AG|Zeiss]] optical works in [[Jena]], on the largest mechanical planetarium ever constructed, capable of displaying both [[heliocentric]] and [[geocentric]] motion. This was displayed at the Deutsches Museum in 1924, construction work having been interrupted by the war. The planets travelled along overhead rails, powered by electric motors: the orbit of Saturn was 11.25 m in diameter. 180 stars were projected onto the wall by electric bulbs.

While this was being constructed, von Miller was also working at the Zeiss factory with German astronomer [[Max Wolf]], director of the [[Landessternwarte Heidelberg-Königstuhl]] observatory of the [[University of Heidelberg]], on a new and novel design, inspired by [[Wallace W. Atwood]]'s work at the [[Chicago Academy of Sciences]] and by the ideas of [[Walther Bauersfeld]] and [[Rudolf Straubel]]<ref>{{cite web|last=Engber|first=Daniel|title=Under the Dome: The tragic, untold story of the world's first planetarium|url=http://www.slate.com/articles/health_and_science/science/2014/02/planetarium_history_nazis_persecuted_inventor_rudolf_straubel_of_zeiss.html|work=[[Slate (magazine)|Slate]]|date=24 February 2014 |publisher=[[The Slate Group]]|access-date=24 February 2014|url-status=live|archive-url=https://web.archive.org/web/20140224122914/http://www.slate.com/articles/health_and_science/science/2014/02/planetarium_history_nazis_persecuted_inventor_rudolf_straubel_of_zeiss.html|archive-date=24 February 2014}}</ref> at [[Carl Zeiss AG|Zeiss]]. The result was a planetarium design which would generate all the necessary movements of the stars and planets inside the optical projector, and would be mounted centrally in a room, projecting images onto the white surface of a hemisphere. In August 1923, the first (Model I) [[Zeiss-Planetarium Jena|Zeiss planetarium]] projected images of the night sky onto the white plaster lining of a 16 m hemispherical concrete dome, erected on the roof of the Zeiss works. The first official public showing was at the Deutsches Museum in Munich on October 21, 1923.<ref name="twothousand">{{Cite news |last = Chartrand |first = Mark |date = September 1973 |title = A Fifty Year Anniversary of a Two Thousand Year Dream (The History of the Planetarium) |periodical = The Planetarian |publisher = International Planetarium Society |volume = 2 |issue = 3 |url = http://www.ips-planetarium.org/planetarian/articles/twothousandyr_dream.html |issn = 0090-3213 |access-date = 2009-02-26 |url-status = dead |archive-url = https://web.archive.org/web/20090420022543/http://www.ips-planetarium.org/planetarian/articles/twothousandyr_dream.html |archive-date = 2009-04-20 }}</ref><ref name=ieee>{{cite web |last1=Marsh |first1=Allison |title=A Brief History of the World's First Planetarium - IEEE Spectrum |url=https://spectrum.ieee.org/planetarium-history |website=[[IEEE]] |access-date=23 May 2024 |language=en}}</ref>

Zeiss Planetarium became popular, and attracted a lot of attention. Next Zeiss planetariums were opened in Rome (1928, in [[Aula Ottagona]], part of the [[Baths of Diocletian]]), Chicago (1930), Osaka (1937, in  the [[Osaka City Electricity Science Museum]]).<ref name=ieee/>