With the 18th century work of Herschel, Laplace, and the ensuing efforts of 19th century astronomers, both theoretical and observational cosmology crossed the threahold of a new era. The discovery of a supernova in the Andromeda nebula (1880's) came as a surprise to some, to others it was confirmation of what they had suspected all along: Our galaxy was not unique. Immanuel Kant had written about this possibility in his influential Universal Natural History and Theory of the Heavens (1755).

Following suggestions from a certain Mr. Wright of Duram__who regarded the fixed stars as a system with the greatest resemblance to that of the planets, rather than a randomly scattered swarm__Kant wrote of the stars in our Milky Way as forming a circular plane. Furthermore he wrote "I consider the species of nebulous stars, of which De Maupertuis makes mention in his treatise "On the Figure of the Fixed Stars" which present the form of more or less open elipses: and I easily persuade myself that these stars can be nothing else than a mass of many fixed stars...And I further saw that that, on account of their feeble light, they are removed to an inconceivable distance from us."

[snip]

"We see that at immense distances there are more of such star-systems, and that the creation in all the infinite extent of its vastness is everywhere systematic and related in all its members...The plan of their revelation must therfore, like themselves, be infinite and without bounds." Kant, 1755)

Kant was 31 years old when he wrote what is often credited to E. Hubble: the discovery that galaxies (nebula) are star systems that lie beyond the Milky Way, and thus enlarging our view of the heavens.

Hubble, Einstein, de Sitter (and others) were almost certainly familliar with Kant's theory (which by the way introduced several aspects of what would later find its way into relativistic cosmology, from SR to the big bang: He had written about "the power of expansion poportional to the heat...the most violent conflagration...the most volatile matter" with obvious Newtonian influence). M. Friedman noted that reference to the Kantian framework was almost necessary arbitration in all debate of the foundations of physical science up until the early 1930's.

I don't recall seeing one equation in Kant's seminal work(s).

Coldcreation