The discussion centers on whether a supermassive black hole could end the universe. It is suggested that while a black hole could have devastating effects on nearby celestial bodies, it would not ultimately end the universe due to the dominance of dark energy, which is accelerating the universe's expansion. Participants note that if a black hole were to approach the solar system, its gravitational effects would be observable long before any catastrophic event occurred. The conversation also touches on the nature of gravitational attraction and the forces acting on bodies in the universe. Ultimately, the consensus is that a supermassive black hole cannot end the universe.