2011/12/09 by Christopher M. Graney, Graney, Christopher M.
Physics and Astronomy · #FOS: Physical sciences #Historical Astronomy and Related Studies #History and Developments in Astronomy #History and Philosophy of Physics (physics.hist-ph) #Popular Physics (physics.pop-ph) #physics.hist-ph #physics.pop-ph
paper · pdf · doi:10.48550/arxiv.1112.1988
20 pages, 4 figures, 2 tables + figures. v2 includes improved Gingerich reference on Tycho, minor corrections
openalex publication_date 2011/12/09 · arxiv created 2012/01/06 · arxiv updated 2012/01/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Tycho Brahe, the most prominent and accomplished astronomer of his era, made measurements of the apparent sizes of the Sun, Moon, stars, and planets. From these he showed that within a geocentric cosmos these bodies were of comparable sizes, with the Sun being the largest body and the Moon the smallest. He further showed that within a heliocentric cosmos, the stars had to be absurdly large - with the smallest star dwarfing even the Sun. (The results of Tycho's calculations are illustrated in this paper.) Various Copernicans responded to this issue of observation and geometry by appealing to the power of God: They argued that giant stars were not absurd because even such giant objects were nothing compared to an infinite God, and that in fact the Copernican stars pointed out the power of God to humankind. Tycho rejected this argument.