  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.
