There are plenty of theories about how the universe began. But what about the question of how it will all end? Humanity's final moments could be due to what's called vacuum decay, the big rip or heat death. Astrophysicist, Dr. Katie Mack, is obsessed with our cosmic future and says there's a certain freedom in knowing how it could all end.

• GUEST: Dr. Katie Mack, Hawking Chair in Cosmology and Science Communication at the Perimeter Institute for Theoretical Physics, Canada.
• PRODUCER: Ali Benton