703 Thackeray Hall

### Abstract or Additional Information

The Schwarzschild solution is the simplest model of the gravitational effect of a clump of dense matter as seen from very far away: a black hole. It is commonly-known that there is a future event horizon, behind which lurks the singularity. It is less commonly known that there is also a past event horizon, and the solution admits a canonical analytic extension in which there is a past singularity: a white hole. There is also a region where the past and future event horizons meet: the throat. This talk will describe the null geodesics that go from the white hole singularity to the black hole singularity, by way of the throat. It shall emphasize the use of complex variables to discuss these geodesics, and should serve as an introduction to the complexification of the null geodesics in the extended Schwarzschild u