Editing Mount Wilson Observatory (section)

=== 50-foot Stellar Interferometer ===

To expand on the work of the 20-foot interferometer, Pease, Michelson and George E. Hale designed a 50-foot interferometer which was installed at Mount Wilson Observatory in 1929. It successfully measured the diameter of Betelgeuse, but, other than beta Andromedae, could not measure any stars not already measured by the 20-foot interferometer.<ref>{{cite journal |last=Vaughan |first=Arthur H. Jr. |title=Interferometer Measurement of Star Diameters |url=http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1967ASPL...10...57V&db_key=AST&page_ind=0&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES |journal=[[Astronomical Society of the Pacific]] |date=August 1967 |volume=10 |issue=458 |page=57 |bibcode=1967ASPL...10...57V |access-date=21 September 2020}}</ref>

Optical interferometry reached the limit of the available technology and it took about thirty years for faster computing, electronic detectors and lasers to make larger interferometers possible again.