Editing 1925 in science (section)

==Astronomy and space science==
* January 1 – [[Cecilia Payne]] completes her PhD thesis ''Stellar Atmospheres: a Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars''<ref>{{cite thesis|last=Payne|first=Cecilia H.|title=Stellar Atmospheres: a Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars|publisher=Radcliffe College|year=1925|type=PhD|bibcode=1925PhDT.........1P|oclc=1443459|id={{ProQuest|301786588}}}}</ref> at [[Radcliffe College]] of [[Harvard University]], providing spectral evidence that stars are composed almost entirely of hydrogen with helium, contrary to scientific consensus at the time; however, her findings will be vindicated by 1929 and astronomer [[Otto Struve]] will describe her work as "the most brilliant PhD thesis ever written in astronomy".<ref>{{cite web|url=https://www.aps.org/publications/apsnews/201501/physicshistory.cfm|title=January 1, 1925: Cecilia Payne-Gaposchkin and the Day the Universe Changed|website=American Physical Society|date=January 2015|accessdate=2021-04-01}}</ref>