Science in Film

At approximately the 80 minute-mark, McConaughey's son sends a "final" message, essentially telling his father goodbye and accepting a form of "death". Explore the psychological implications of the perception that each person has experienced. McConaughey has only been perceiving a couple of months, while close to three decades have been perceived by others. What is "real" in a world of relativity?

Both gravity and love are explored in this movie, and their are compared in ways that argue that they are somewhat scientifically equivalent. Both are intangible yet affect humans. Both cannot be explained yet are undeniably present. Any yet, one is considered a "hard science" and the other is considered a "soft science". Why?