Christopher Nolan's film INTERSTELLAR has been given some flack about the speech the character of crew member Brand, played by Anne Hathaway, gives about "the power of love". Speaking as a person who has two science degrees, I would agree that the idea that love has some supernatural power over physics is a bunch of hooey. But it certainly has a lot of power of _us_. Which is exactly what the character of Mann, played by Matt Damon, says. He talks about how our instinct for survival, not just for ourselves, but for our children, our extended family, and even our species, drives us to make sacrifices that we might otherwise not contemplate, to drive ourselves beyond our normal limits, or to take actions that might seem selfish in a broader context. That appeals to the graduate student in me who read "The Selfish Gene" decades ago. Nolan steps back and encourages us to choose either viewpoint, the emotional one, or the intellectual one, in which to interpret the events in the last part of the film. I choose the Mann Hypothesis: far future decendents of the human race, having long transcended into the singularity, reach back by perceiving time as a physical spatial dimension, to insure their own existence by influencing events in their past. Cooper, the character played by Matthew McConaughey, makes his own sacrifices, in an effort to insure the survival of his children. Mann and Brand both make their sacrifices, the former for his own life, and latter for the survival of her species. The nature of sacrifice can be seen as the underlying theme of film. I chose the Mann Hypothesis, but it was a kind of smart screenwriting for Nolan to make the film accessible to those who would choose the Brand Hypothesis.