Uber-Morlock: You built your time machine because of Emma's death. If she had lived, it would never have existed. So how could you use your machine to go back to save her?
When Philby and Alexander are talking about Albert Einstein, Alexander mentions that Einstein is a patent clerk. The beginning of this movie takes place in the year 1899. Einstein was still in school and didn't become a patent clerk until 1902.
At the end of the movie, when Mrs. Watchitt is standing in the doorway, there is a picture of H.G. Wells hanging on the wall behind her.