Dr. Katherine (Katie) Mack is a theoretical astrophysicist who studies a range of questions in cosmology, the study of the universe from beginning to end. She currently holds the position of Assistant Professor of Physics at North Carolina State University, where she is also a member of the Leadership in Public Science Cluster. Throughout her career she has studied dark matter, the early universe, galaxy formation, black holes, cosmic strings, and the ultimate fate of the cosmos. Alongside her academic research, she is an active science communicator and has been published in a number of popular publications such as Scientific American, Slate, Sky & Telescope, Time.com, and Cosmos Magazine, where she is a columnist. Her forthcoming book, The End of Everything, takes readers through five universe-ending possibilities. It will be published by Scribner in 2020. You can find her on Twitter as @AstroKatie.