What we knew about hyperbolic geometry before we knew about hyperbolic geometry
Evelyn Lamb (Self-employed)
MSRI: Simons Auditorium
Like violets in spring, hyperbolic geometry sprouted up in several different places in the early 19th century. But the seeds had been germinating for quite some time before then. We will explore some of the first investigations into the parallel postulate and its negations, from ancient Greece to medieval Persia to Italy in the early modern age. What were people able to prove about hyperbolic geometry before they even acknowledged that it could exist?