Mary Steenburgen's main reason on deciding to do this film was because she was always a fan of Alan Rickman and always wanted to work with him.
Alan Rickman wore prosthetic teeth for his role as Eli Michaelson.
When Eli and Sarah are back in their house with the reporters on their lawn, the scene pans between the characters and the mantel. On the mantel is a black and white picture of a man with a mustache which actually happens to be younger Alan Rickman, probably from Truly Madly Deeply.
Mary Steenburgen and Ted Danson are married in real life, but their characters never interact. Danson's role is little more than a cameo.
The first American Nobel Prize winner in sciences was Michelson (without a) his first name was Albert.